25 Years of Change in Optical Manufacturing and Product Specs Manufacturing optics has seen extensive developments over the last 25 years.  In the past, optical manufacturing relied heavily on manual processes and standardization. Customization was difficult, and optical parts were typically produced with high tolerances. Today, techniques such as nanotechnology, additive manufacturing (3D printing) and CNC manufacturing enable us to custom produce precision optics with almost any geometry desired. What does this mean in practice? Let’s take a closer look at the evolution of manufacturing in two specific product lines: aspheric lenses and microscope objective lenses.  Advances in Optical Manufacturing: The Aspheric Lens Aspheric lenses are lenses designed to eliminate spherical aberrations, coma, field distortions, and astigmatism, among other aberrations. They have a non-spherical profile and focus light to a small point. 25 years ago the manufacturing of aspherical lenses was an extremely expensive undertaking, but today we can produce these lenses at scale and at a price point that makes them affordable for applications across industry, research, medicine, and defense. Today, aspheric lenses are included even in consumer products. Optical advances mean that today we can produce high quality aspheric lenses at a better price point than ever before. What made the difference? Changes in manufacturing technology, advances in materials, and innovations in computational design were all part of it.  Modern materials such as plastics and advanced optical glasses not only provide high optical qualities like reduced chromatic aberrations, they are, in some cases, easier to form into non-spherical optics. Plastics, for instance, lend themselves well to molding and can thus be shaped into any aspherical form desired. New Manufacturing Techniques like computer controlled precision polishing enable us to perfect even the most intricate aspheric shapes. Other  manufacturing techniques like advanced glass molding and injection molding have seen vast improvements over the past two decades. This new new fine control of the manufacturing process enables us to produce miniature aspheres as well as  custom pieces created to our customers’ exact specifications. Innovations in Computational Design allow our optical designers to calculate the ideal geometry for an asphere given required specifications and application notes.  Advances in Optical Manufacturing: Microscope Objective Lenses Microscope objective lenses are the optical centerpiece of the microscope. They consist of a multi-lens assembly and are placed so as to accept light emitted by the object (specimen) being imaged. Perhaps not surprisingly, the objective lens is the most difficult part of a microscope to design and produce, and the quality of the final image is directly related to the quality of the objective. Microscope objectives have seen innovations in materials, design, and manufacturing technology over the past 25 years Microscope objective lenses can be produced with increased numerical aperture and increased magnification when compared to 25 years ago. Examples of these in use include ultra-high resolution objectives for applications like STED (Stimulated Emission Depletion) microscopy and PALM (Photo-Activated Localization Microscopy.)  Just as we saw when we looked at the evolution of aspheric lenses, improvements in objective lenses have been driven by three key factors: advances in materials and manufacturing technology and innovations in design.  Modern materials used in microscope objectives include advanced substrates like fluorite glass.  Many modern objectives also feature enhanced optical coatings, which minimize optical aberrations, reduce light loss and increase contrast. This enables the microscope to produce images that are sharper and more vibrant, even under high magnification. Design innovations include the refinement of flat-field corrected objectives as well as  immersion lens systems.  We’ve become adept at creating smaller, more compact objective lenses that perform better than the bulky system of yesterday.  These lenses may be designed with the special needs of fluorescence and confocal microscopy in mind, enabling them to be used for high contrast imaging of living cells. Advances in manufacturing technology enable us to produce high quality objectives in a more efficient, cost-effective manner than before, and to conduct extensive automated quality controls on each piece before it is assembled into the final objective. This is only a small survey of some of the advances we’ve seen over the past twenty-five years. If you’d like to find out more, have a look at our article on how optical innovations like these are fueling technological change. References Blom, H and Widengren, J. Stimulated Emission Depletion Microscopy. Chemical Reviews 2017 117 (11), 7377-7427.  Singh, R.,  and Chen, Y.  “Comprehensive advancements in automatic digital manufacturing of spherical and aspherical optics,” Proc. SPIE 12769, Optical Metrology and Inspection for Industrial Applications X, 127690B (27 November 2023); Spring, Keller, & Davidson. Microscope Objectives Introduction. Evident Scientific,  Yin, S., Jia, H., Zhang, G. et al. Review of small aspheric glass lens molding technologies. Front. Mech. Eng. 12, 66–76 (2017).  Related content

25 Years of Change in Technology and Features of Optics, optical technologies The past 25 years have seen enormous advances and transformations in optics and optical technologies. Here we’ll look at just what changed— and how these changes are transforming our lives, work, and research.  Then and Now: 25 Years of Optics What would most surprise a time-traveling visitor from 2000, visiting today’s optical factory? Would it be the sleek, high-performance optics that come in smaller and smaller sizes, with finely crafted detail that the naked eye cannot even distinguish? Would it be the versatile flexibility in free-form optics, or the economical new ways we have of manufacturing aspheres to scale? Would it be the new lightweight, eco-friendly materials we have to work with, or our abilities to use computer technology to polish and perfect precision optics to meet even the highest standards? All this— and much more. The history of optics, from the time when Egyptians and Mesopotamians crafted their first lenses till now is marked with multiple periods of fast growth and multiple key milestones, but there’s something special about the rate of recent progress. Optics has come into its own, and the optical industry is advancing at exponential rates. What happened to make today’s optics so much smaller, smarter, and more efficient? Let’s look at 25 years of progress, condensed into one brief page.  Smaller Microlenses aren’t new— but the techniques we use to produce them have changed dramatically, giving  flexibility that just wasn’t there 25 years ago. We’ve also learned how to manufacture thinner, lighter, standard components and how to make a tiny assembly do the job that before required a large, clunky collection of optical components.  One example of this is the digital camera of 2000. Back then we’d figured out the technology to take digital pictures, but it came in a cumbersome package that required delicate treatment. Today, we’ve managed to condense that same capability into fingerprint-size in a  smartphone camera— and make it robust enough you can carry it around in your pocket.  Smarter Look through any lineup of modern optical products versus older versions, and you’ll notice immediately that today’s optical products are  smarter than they were yesteryear. 25 years ago even complex assemblies relied on analog components and had limited functionality. In most cases, they required extensive manual control. Today, by contrast, optics are coupled with advanced computer technology and AI to create highly automated systems that require a minimum of personal guidance and intervention. Automation, real-time data analysis and adaptive functionality can easily be built into an optical system.  But there’s another important way that the optical industry has got smarter: manufacturing processes are smarter too. Take the process of polishing a precision lens— no longer do we need to rely on manual labor; instead, computer-controlled polishing can ensure that the final result Is as smooth and blemish-free as the application requires, even if the optic is not a standard spherical shape.  More Efficient But today’s optics aren’t only smaller and smarter– they’re also more streamlined and efficient.  You’re likely to have noticed that most of the optics you work with on a day to day just work better than those you used even ten years ago. Advances in design mean we’re better at correcting aberrations than we were, and enhanced optical coatings enable us to fine-tune the function of an optical component in a way that was never before possible.  As an optical designer and manufacturer, we’ve also perfected more efficient manufacturing processes for many optical components that used to be impractical to produce at scale. Free-form optics, aspheres, and micro-optics are just some examples of specialized components that used to be very limited 25 years ago and can be produced on scale today.  Efficient manufacturing processes for optical components like aspheres enable them to be produced at an affordable price bracket and at scale New Materials, More Durability One of the secrets to the advances in optics we see today lies in the use of advanced materials like composites, silicon carbide (SiC),  and lightweight alloys. Many traditional optical materials were heavy and environmentally unfriendly, and often they lacked industrial strength and durability. Something as simple as changing the substrate used can result in enormous changes in performance, lifespan, and environmental sustainability.  Modern materials that were not available 25 years ago enable us to produce optics that are stronger, better, and more efficient. The enhanced durability of many modern materials leads to one special side effect: simpler assemblies. No longer do we have to use over-engineering to ensure system durability. Instead, it’s built-in from the substrate up. 25 Years of Advances: Product Specs and Optical Applications If this article has whet your appetite and you’d love more detailed information on how optics have changed over the past twenty-five years, have a look at our two special articles detailing changes in product specs and in optical application. And if you’d like to inquire how you can harness some of these technological advances in your own application, contact us today!  References Corning, Anne. The Latest Advancements in Optics. March 18, 2024.  Hecht, Jeff. Photonic Frontiers: Optics: Looking back/Looking forward: A transformation of optical components. Jan 2015, Laser Focus World,  Rivera, Lanie. Optics Become Less Rough, More Tough. July/August 2016, Science & Technology Review,  Winzer, P.  et al.”Fiber-optic transmission and networking: the previous 20 and the next 20 years [Invited],” Opt. Express 26, 24190-24239 (2018) Wikipedia contributors, “History of optics,” Wikipedia, The Free Encyclopedia, Related content

Key Takeaways Photoacoustic Microscopy (PAM) is a high-resolution imaging technique that integrates optical and acoustic methods to overcome the optical diffusion limit.  It enables in vivo imaging at depths of several millimeters using endogenous and exogenous contrast agents.  PAM is categorized into optical-resolution (OR-PAM) and acoustic-resolution (AR-PAM) types, each suited for different depth ranges. Applications include medical diagnostics, surgical guidance, and disease research.  Avantier provides custom optics for PAM, supporting breakthroughs in imaging speed and quality, including real-time intraoperative histology. Photoacoustic Microscopy Photoacoustic microscopy (PAM) is a cutting-edge in vivo tissue imaging technique that combines optical and acoustic methods to break through the optical diffusion limit. It is capable of producing images with high spatial resolution at depths up to several millimeters and can simultaneously image multiple contrasts. One could, for instance, use these methods and different contrasts for anatomical, functional, flow dynamic, metabolic, and molecular image modalities.  How Does Photoacoustic Microscopy Work? Photoacoustic microscopy begins with light: typically, a nano-second pulsed laser beam. It is this laser pulse energy that triggers the acoustic effect.  Photons, absorbed by tissue, cause a local temperature rise. Weak acoustic scattering occurs as the tissues expand in a thermo-elastic way, and the resulting wide-band acoustic wave can be detected by ultrasound technology.  The energy is converted into a voltage signal, and a one-dimensional, depth-encoded image, called an A-line, is created for each laser pulse. 2D raster scanning is then used to form a 3D photoacoustic image from multiple one-dimensional A-lines. Photoacoustic microscopy uses both light and acoustic methods to produce an image more detailed than could be produced by either method alone The key to in vivo imaging with PAM is the deep penetration of diffused photons and the low scattering of sound — 1000 times less than that of light. This enables researchers to produce quality imaging at a depth impossible with only optical methods and also enables them to determine the exact penetration depth at which imaging should occur. This versatility  means one can use the same methodology for high resolution imaging of a mouse ear and a mouse brain, for instance. Axial resolution is determined by the bandwidth of the ultrasound transducer.  There are two main types of photoacoustic microscopy; OR-PAM, optical resolution photoacoustic microscopy, where the optical focus is tighter than the acoustic focus, and AR-PAM, acoustic resolution photoacoustic microscopy, where the acoustic focus is tighter. OR-PAM is typically used for depths up to 1 mm, and AR-PAM for depths from 1-3mm.  Optical properties of the tissue being imaged determine the contrast of the image. Non-invasive endogenous contrast agents such as intrinsic red blood cells, DNA, lipids, and glucose can be used as contrast absorbers.  For other applications, exogenous contrast agents such as organic dyes, nanoparticles, or fluorescent proteins may be used. Photoacoustic microscopy can produce high resolution images with endogenous contrast agents. This graph compares the absorption spectra of some of the more common contrast agents found in biological tissue Applications of Photoacoustic Microscopy PAM imaging is particularly important in medicine and research, where it provides a window into what is happening inside otherwise opaque tissue. It may be used for diagnostics, providing valuable data on blood flow, oxygen metabolic rates, or tumor growth.  It can also be used to guide a surgeon’s knife in delicate surgeries, or to gain a better understanding of the changes that occur in diseased tissue.  One example of photoacoustic microscopy in action in medical research is in the study of inflammatory skin diseases. Using PAM combined with optical coherence tomography, researchers were able to determine oxygenation differences as well as thickened epidermis, vascular patterns with dilated vessels in a disorderly network, and the absence of melanin in eczematic in skin tissue.  Photoacoustic Microscopy at Avantier At Avantier, we specialize in producing high quality custom optics for applications like photoacoustic microscopy. Our clients have been able to push past the limits of known technologies and achieve novel imaging speeds and quality. One example is the authors of a recent paper in Science Advances, Optical-resolution parallel ultraviolet photoacoustic microscopy for slide-free histology, who used a custom F-theta lens produced by Avantier  to achieve the imaging speeds needed for potential real time intraoperative photoacoustic histology.  Do you have an optical project you’d like to take to the next level? Our experienced engineering and design teams are available to work with you to design and bring to production the exact optical components or systems your application requires. Contact us today for your next project.  References Attia ABE, Balasundaram G, Moothanchery M, Dinish US, Bi R, Ntziachristos V, Olivo M. A review of clinical photoacoustic imaging: Current and future trends. Photoacoustics. 2019 Nov 7;16:100144  Ning, B., Sun, N., Cao, R. et al. Ultrasound-aided Multi-parametric Photoacoustic Microscopy of the Mouse Brain. Sci Rep 5, 18775 (2016). Rui Cao et al. ,Optical-resolution parallel ultraviolet photoacoustic microscopy for slide-free histology.Sci. Adv.10,eado0518(2024). Yao J, Wang LV. Photoacoustic Microscopy. Laser Photon Rev. 2013 Sep 1;7(5):10.1002/lpor.201200060. doi: 10.1002/lpor.201200060. PMID: 24416085; PMCID: PMC3887369. Zabihian B., Weingast J., Liu M., Zhang E., Beard P., Pehamberger H., Drexler W., Hermann B. In vivo dual-modality photoacoustic and optical coherence tomography imaging of human dermatological pathologies. Biomed. Opt. Express. 2015;6(9):3163–3178. doi: 10.1364/BOE.6.003163. Related Content

Key Takeaways LiDAR enables advanced VR experiences by providing precise, real time 3D spatial mapping.  Once bulky and expensive, modern LiDAR systems are now compact enough to fit into smartphones like the iPhone Pro 12.  This technology enhances VR/AR experiences with benefits such as better spatial tracking, faster virtual object placement, enhanced realism, and improved depth sensing.  Key specifications include detection range, range precision, accuracy, field of view, and scan patterns.  Avantier specializes in designing high precision LiDAR components, enabling customized solutions for AR/VR applications. LiDAR VR/AR Applications LiDAR VR/AR  applications are taking augmented and virtual reality applications to the next level. Once far to expensive and bulky for consumer applications, today a basic LiDAR system can be condensed to fit into a smart phone and cost less than a hundred dollars. Here we’ll look at just how they work, and what to expect from the combination of LiDAR and AR/VR. LiDAR for AR/VR makes augmented or virtual reality more responsive What is LiDAR? Think of LiDAR as optical radar. An acronym for Light Detection and Ranging, it uses light waves from a laser to create a highly accurate, super-speedy 3D map of an object or area. Wavelength of the laser is typically 250 nm to 11μm but depends on the application requirements. A quick working sensor makes time of flight  (TOF) calculations— determining just how long each laser pulse takes to reach the target and return— and uses this raw data  and point clouds to create a precise 3D map of terrain or objects and their placement in space. The intensity of the reflected light can provide extensive information, too, about the type of materials scanned and their density. LiDAR for AR/VR uses time of flight principles to determine the topology of an object or landscape LiDAR scanners were originally developed for research purposes, especially meteorology applications. It was successfully used to map the surface of the moon back in 1971, but the technology behind it has improved dramatically and LiDAR today is cheaper, faster, and more powerful than ever before. This new affordability is part of the reason behind the explosion of LiDAR use across real world industries today. We see it in self-driving cars, in speed enforcement, in stormwater management in agriculture— and in AR/VR. LiDAR and AR Before the integration of LiDAR with augmented reality, AR was limited by clunky machine vision systems that struggled to provide precise real time 3D mapping. Today, with precise spatial mapping at the speed of light, LiDAR gives AR and VR systems the potential to be faster, more accurate, and so more responsive. Today LiDAR for AR/VR can be condensed to fit inside a smartphone When Apple integrated a miniature LiDAR system into the 2020 iPad Pro and iPhone Pro 12, the power of LiDAR became available to AR and VR app makers for the first time. Since then, they’ve been experimented with extensively.  There’s more than one way that augmented reality (AR) and virtual reality systems can be improved by LiDAR integration. A few benefits of the integration include: Better Spatial Tracking Faster Placement of Virtual Objects Enhanced Realism Improved Depth Sensing LiDAR for AR/VR Specifications Producers of smartphones and AR and VR viewing devices today have the potential to take their viewer’s experience to the next level by incorporating LiDAR technology into their devices. But types and capabilities of LiDAR scanners vary greatly. Here’s a brief summary of some of the most important specs for AR/VR LiDAR. The LiDAR Detection Range gives the maximum distance at which LiDAR can detect an object. It is dependent on laser power, laser type, and aperture size.  While airborne LiDAR may be used to map surfaces hundreds to thousands of meters away, the types of LiDAR incorporated in consumer devices typically have a much more limited detection range. The iPhone Pro 12’s LiDAR, for instance, can scan at distances up to five meters.  LiDAR Range Precision tells you just how repeatable measurements will be. If precision is high, multiple measurements of the same object will cluster close to a mean value; but low precision tells you there is significant scatter. LiDAR Range Accuracy is like precision, but rather than comparing measurements to each other, it compares them to the actual distance. High accuracy means measurements are very close to the real distance. Field of View (FOV) refers to the angle over which the LiDAR system works: either the angle covered by the sensor or that which signals are emitted, whichever is smaller. A mechanically rotating system may have 360 degree field of view, but for many virtual reality applications, a smaller FOV is sufficient.  Scan Pattern tells you how the laser beam moves to perform its measurement, and includes information like point density and the number of scan lines. In some LiDAR scanners, this may be customizable. AR/VR LiDAR at Avantier Avantier is a premier producer of custom high precision optics, including LiDAR components and systems built to our customer’s exact specifications. Our expert engineers and designers are available to help you at any stage of the process, whether you’re doing your initial research or have a custom design ready to go.  Contact us today for your next project. References Applied Tech Review. LiDAR Powering Future AR/VR and Metaverse Experiences. May 2024.  Luetzenburg, G., Kroon, A. & Bjørk, A.A. Evaluation of the Apple iPhone 12 Pro LiDAR for an Application in Geosciences. Sci Rep 11, 22221 (2021).  Wandinger, Ulla. “Introduction to lidar.” Lidar: range-resolved optical remote sensing of the atmosphere. New York, NY: Springer New York, 2005. 1-18.  Related Content

Product Highlights Parabolic mirrors can focus collimated light without introducing spherical aberration. An Off-Axis Parabolic mirror  (OAP mirror) is a segment taken from a larger parabolic mirror.  When collimated light strikes an OAP mirror, it is focused to a point. Unlike a centered parabolic mirror, an OAP mirror offers the advantage of providing more space around the focal point, allowing for greater interaction with the beam without disrupting it. OAP mirrors offer precise beam control, are chromatic aberration-free, and come in various configurations.  Reflective coatings (metal or dielectric) enhance performance. The off-axis design and material choices impact cost and precision. Introduction to Off-Axis Parabolic Mirrors Off-axis parabolic mirrors (OAPs) are a widely used type of aspherical mirror, known for their ability to converge and collimate light beams efficiently. These mirrors are designed by extracting a portion of a parent paraboloid, resulting in unique optical properties. Unlike traditional lenses, off-axis parabolic mirrors leverage reflection, eliminating chromatic aberration and providing superior beam manipulation. Key Features and Advantages Precision Beam Control The paraboloidal surface of OAPs ensures perfect correction of spherical aberration, enabling precise convergence and collimation of light. The off-axis design separates the focus from the optical axis, allowing these mirrors to simultaneously perform beam steering while converging or collimating light. Chromatic Aberration-Free Unlike refracting optics, OAPs do not rely on material dispersion, making them ideal for applications requiring high optical precision across a broad spectrum of wavelengths. Core Parameters of Off-Axis Parabolic Mirrors Clear Aperture The clear aperture represents the maximum diameter of a parallel light beam that the mirror can handle. It is typically circular, ensuring efficient optical performance. Focal Length Focal length defines the distance between the mirror surface and its focal point: – Parent Focal Length: Distance from the paraboloid vertex to the focus, independent of the off-axis distance. – Effective Focal Length (EFL): Distance between the focus and the main reflected beam, influenced by the parent focal length and off-axis displacement. Off-Axis Distance and Angle The off-axis configuration is defined by: – Off-Axis Angle: The reflection angle of the main beam, typically between 0° and 90°. – Off-Axis Distance: The lateral distance between the paraboloid’s symmetry axis and the main ray. Customization Options OAP mirrors can be tailored with surface shape accuracy, reflectivity, surface finish, and additional features such as holes or mounting mechanisms based on user requirements. Diagram of an Off-axis parabolic mirror Reflective Coatings To maximize performance, OAP mirrors are coated with reflective films suited to specific applications. Below are the common coating types: Metal Coatings Aluminum Coating: Offers wideband reflectivity, particularly effective in the ultraviolet range when combined with magnesium fluoride. It is durable and economical, with reflectivity exceeding 80% in the visible spectrum. Silver Coating: Provides high reflectivity (95% in the visible and over 97% in the infrared) but is unsuitable for UV applications due to high absorption. Requires a controlled environment due to lower durability. Gold Coating: Optimal for infrared applications, with high reflectivity beyond 650 nm. Gold coated OAP mirrors are also highly resistant to laser damage and have minimal phase delay effects. Dielectric Coatings Dielectric coatings are multilayer stacks of materials with varying refractive indices. These coatings offer: – High Reflectivity: Can achieve over 99.9% reflectivity. – Custom Bandwidth: Tailored for specific wavelength ranges. – High Laser Damage Threshold: Suitable for high-power applications. Dielectric coatings are sensitive to incident angles, causing reflectivity peaks to shift towards shorter wavelengths at higher angles. OAP Mirror Applications Off-axis parabolic mirrors are indispensable in fields such as: Astronomy Laser systems Spectroscopy Optical communications Biomedical imaging Their unparalleled optical precision and versatility make them essential components in advanced optical systems. By understanding their core parameters and coating options, users can effectively integrate OAPs into their applications for optimal performance. Design specifications OAP mirrors have a complex design that requires careful attention to detail and advanced knowledge for successful creation. Only skilled engineers can design a specific OAP mirror that meets the necessary specifications and is suitable for its intended application. This section includes a schematic of the OAP mirror.  Detailed image of OAP Mirror The beam’s aperture can be either circular or square and is aligned with the Z axis. Depending on the angle, the size of the aperture on the optical surface may look elliptical or rectangular. For optics with large off-axis angles or apertures, a non-wedge design is often more affordable. This design allows you to set a tilt angle in relation to the main Z axis. You can make off-axis parabolic mirrors (OAP mirrors) from different materials, like metals (using single-point diamond turning), glass, and special ceramics such as SiC. The material you choose will greatly affect both the cost and precision of the mirrors. For more information, please visit the in-depth article. ” OAP Mirror “ Examples of projects The following is a physical introduction of the off-axis parabolic mirror: Conventional off-axis parabolic mirror Aperture: 1 inch and 1/2 inch, Surface accuracy: <1/4L Coating:  protected Ag or Au Off-axis angle: 45° Material: 6061 Al Conventional off-axis parabolic mirror Large aperture off-axis parabolic Mirror 1 Aperture: 400mm Surface accuracy: <1/2L Coating: Protected Ag Off-axis angle: 30° Material: fused silica Large aperture off-axis parabolic Mirror Large aperture off-axis parabolic mirror 2 Aperture: 300mm Surface accuracy: <1/3L Coating: dielectric film Off-axis angle: 40° Material: Zerodur Large aperture off-axis parabolic mirror Custom Off-Axis Parabolic Mirrors At Avantier Inc., we specialize in producing custom high-performance Off-Axis Parabolic (OAP) Mirrors for a variety of applications. We offer a wide range of coating options, including protected gold, protected silver, and protected aluminum. For visible and infrared applications, protected aluminum is typically a recommended choice. We can provide SM-threaded, unthreaded, or post-mountable adapters for any in-stock OAP mirror. If you are interested in purchasing stock Off-Axis Parabolic Mirrors, please visit our Stock – Off-Axis Parabolic Mirrors page. Our OAP mirrors are diamond-turned to ensure a smooth surface and minimize surface roughness. Contact us today to discuss a custom order for an optical mirror tailored to your desired focal length

Key Takeaways Fourier Ptychographic Microscopy (FPM) is an innovative computational imaging technique that overcomes traditional limitations in microscopy by offering both high resolution and a wide field of view.  Key advances, including ESA-FPM, REFPM, and LRA-piFP, enhance speed, resolution, and robustness.  Applications span digital pathology, drug screening, 3D imaging, and metrology.  Manufacturing challenges include LED precision, optical aberration, and sample thickness limitations. Super-resolution Fourier Ptychographic Microscopy (FPM) FPM addresses the fundamental trade-off between resolution and field of view in conventional microscopy by combining principles of structured illumination, ptychography, and phase retrieval. This technique enables high resolution, wide field imaging using low numerical aperture, low magnification objective lenses. Super-resolution Fourier Ptychographic Microscopy Principles FPM utilizes an array of programmable LEDs for illumination from different angles, expanding the frequency domain bandwidth by overlapping pupil functions. Key components include: LED array illumination: Provides angularly varying illumination to capture multiple low-resolution images of the sample from different incident angles. Low-NA objective lens: Captures wide field-of-view images at low resolution, which are later computationally enhanced. Digital camera: Records the series of low-resolution intensity images corresponding to different illumination angles. Computational reconstruction algorithms: Combines the captured low-resolution images in the Fourier domain to synthesize a high resolution image with both amplitude and phase information. The reconstruction process alternates between spatial and Fourier domains, applying constraints to produce a high-resolution, wide-field complex sample image. The configuration of Fourier ptychography Advantages of Super-resolution Fourier Ptychographic Microscopy High Resolution and Wide Field of View (FOV):  This technology combines the advantages of both high-magnification and low-magnification imaging, allowing for detailed views across large sample areas. Resolution Enhancement: It utilizes computational techniques to improve resolving power beyond the physical limits of the optical system. Phase Retrieval Capabilities: This feature enables the extraction of phase information from samples, allowing for the visualization of transparent structures without the need for staining. Digital Aberration Correction: The system can computationally correct optical imperfections, enhancing image quality without requiring modifications to physical lenses. Recent Advancements Efficient Synthetic Aperture FPM (ESA-FPM) reduces the number of required raw images, significantly decreasing acquisition time. Resolution-Enhanced FPM (REFPM) pushes the resolution limits even further by incorporating advanced optical designs. Low-Rank Approximation FPM (LRA-piFP) improves reconstruction robustness in the presence of noise and environmental perturbations. These advancements have improved acquisition speed, resolution, and robustness against environmental perturbations. Applications Digital pathology: Enables rapid, high-resolution scanning of large tissue samples for diagnostic purposes. Drug screening: Facilitates high-throughput analysis of cellular responses to pharmaceutical compounds. Three-dimensional imaging: Allows for the reconstruction of 3D structures from 2D image data. Label-free imaging: Provides contrast in transparent samples without the need for staining or fluorescent markers. Metrology and scientific research: Offers high-precision measurements for various scientific and industrial applications. Digital pathology Manufacturing Challenges LED array precision: Requires extremely accurate positioning and control of multiple light sources. High precision motorized stage requirements: Necessitates nanometer-level positioning accuracy for sample or optics movement. Illumination brightness consistency: Demands uniform light output across all LEDs in the array. Optical aberration minimization: Requires high-quality optics to reduce inherent system aberrations. Sample thickness limitations: Imposes restrictions on the thickness of samples that can be effectively imaged. Pixel aliasing issues: Necessitates careful consideration of sensor resolution relative to the achieved optical resolution. Case Study: Super-Resolution Imaging of Biological Cells Experimental Setup – Sample: Fixed HeLa cells stained with fluorescent dyes – Microscope: Standard brightfield microscope modified with LED array – Illumination: Programmed LED array for structured illumination – Reconstruction: Fourier ptychographic phase retrieval algorithms Findings Resolution Enhancement: Achieved ~0.6 µm spatial resolution Phase Contrast Imaging: Revealed detailed phase information Large Field of View: 10x larger than confocal systems Cost and Time Efficiency: Significantly more affordable and faster Applications: Detailed visualization of sub-cellular structures Challenges Computational Load: Required GPU-based processing Alignment Sensitivity: Precise calibration needed Noise Handling: Preprocessing steps required Impact and Future Directions – Potential for transformative applications in cancer research, drug development, and pathogen detection – Future focus on live imaging, machine learning integration, and hardware optimization Leading Institutions in FPM Research California Institute of Technology (Caltech) Chinese Academy of Sciences (CAS) University of Connecticut Howard Hughes Medical Institute National Science Foundation (NSF) Fourier Ptychographic Microscopy Advancing Imaging Innovation Fourier Ptychographic Microscopy represents a significant advancement in microscopy techniques, offering high resolution, wide field imaging with phase information. Despite manufacturing challenges, its potential applications in various fields, particularly in digital pathology, make it a promising technology for future research and development. Reference: https://www.nature.com/articles/s41598-017-09090-8 https://medicalxpress.com/news/2024-06-feature-domain-fourier-ptychographic-microscopy.html https://pmc.ncbi.nlm.nih.gov/articles/PMC10887115/ https://pmc.ncbi.nlm.nih.gov/articles/PMC4369155/ https://clpmag.com/diagnostic-technologies/anatomic-pathology/microscopy/fourier-ptychographic-microscopy-may-transform-digital-pathology/ https://pubmed.ncbi.nlm.nih.gov/38391937/ https://phys.org/news/2022-10-rapid-full-color-fourier-ptychographic-microscopy.html Related Content

Key Takeaways: Gravitational wave detection, a groundbreaking astrophysical advancement, relies on precision optical systems in space-based telescopes.  Using laser interferometry, these systems detect spacetime distortions caused by gravitational waves.  Key components include Nd:YAG lasers, beamsplitters, reflectors, and detectors. Challenges involve maintaining thermal stability, alignment, and stray light suppression.  These systems enable the observation of low-frequency waves, revealing phenomena like black hole mergers and early universe signals, advancing gravitational wave astronomy and cosmology. Optical Systems in Space Gravitational Wave Telescopes Gravitational wave detection represents one of the most groundbreaking advancements in modern astrophysics, driving the development of highly sophisticated technologies. At the heart of this innovation lies the optical system of space gravitational wave telescopes, which is integral to achieving the extraordinary precision and stability required for successful measurements. These systems utilize laser beams in a laser interferometer gravitational wave observatory, enabling high-precision interferometry to detect gravitational waves caused by the passing of these elusive ripples through space-time.  Unlike traditional radio telescopes that capture radio waves, these interferometric detectors create stable light paths across vast inter-satellite distances. Such capabilities make them indispensable in gravitational wave astronomy, unraveling the universe’s most enigmatic phenomena. This article explores their purpose, components, configuration, and the challenges faced in this cutting edge field. Purpose of the Optical System Interferometric Detection The optical system’s primary purpose is to detect minute spacetime distortions caused by gravitational waves. This is accomplished by measuring phase differences in laser beams, which indicate changes in distance or spacetime curvature. Precision Requirements These systems must deliver extraordinary sensitivity, capable of detecting changes at the picometer or even femtometer level over distances spanning millions of kilometers. Key Components for Space gravitational wave telescope Laser Source: A highly stable and coherent laser, often a Nd:YAG laser operating at 1064 nm, is used to minimize phase noise, ensuring reliable measurements. Beamsplitter: This component divides the laser beam into separate paths, enabling the creation of interference patterns critical for detecting gravitational waves. Reflectors: Corner cube reflectors or drag-free test masses serve as end mirrors. These components are designed to be minimally affected by external forces, ensuring accurate measurements. Telescopes: High-precision collimation and focusing systems direct the laser beams across vast inter-satellite distances, ensuring beam stability and alignment. Detectors: Photodetectors or quadrant detectors capture interference patterns, allowing for precise measurement of phase shifts caused by gravitational waves. Optical Cavities: These structures enhance sensitivity by increasing the effective path length within the interferometer, thereby amplifying the detection capability. Nd:YAG Crystal Sample Beamsplitter Ritchey-Chrétien Telescopes System Configuration of Space Gravitational Wave Telescopes Michelson Interferometer: A common setup, such as that used in the LISA mission, where laser beams travel between spacecraft to form an interferometer. Long Baseline Interferometry: Space-based systems operate with baselines of millions of kilometers, providing heightened sensitivity to low-frequency gravitational waves in the millihertz range. Drag-Free Systems: Ultra-stable test masses in free fall are employed to isolate the optical system from external forces, ensuring precise detection of gravitational waves. Challenges in Optical System Design Thermal Stability: In the harsh space environment, maintaining thermal stability is essential to prevent thermal fluctuations from distorting optical components. Wavefront Aberration: Optical components must minimize wavefront distortions to ensure accurate measurements over vast distances. Alignment Precision: Spacecraft must maintain precise alignment of their optical systems despite the challenges posed by orbital dynamics and microgravity. Stray Light Suppression: Effective suppression of stray light is critical to avoid contamination of the gravitational wave signal.   Applications Astrophysical Observations: Space gravitational wave telescopes enable the detection of phenomena such as binary mergers, collisions in black holes, and neutron star interactions. Cosmological Studies: These systems provide insights into the early universe by capturing low-frequency gravitational wave signals inaccessible to ground-based detectors. Engineering Space Gravitational Wave Telescope Optical Systems The optical system design of space gravitational wave telescopes is a marvel of engineering, enabling the unprecedented precision required for gravitational wave detection. By overcoming challenges in sensitivity, stability, and alignment, these systems allow scientists to observe cosmic events that would otherwise remain undetectable, opening new windows into the universe’s most enigmatic processes.Related Content

Key Takeaways: Manufacturing space gravitational wave telescopes, like the Engineering Development Unit Telescope and the Laser Interferometer Space Antenna (LISA), requires extreme precision, advanced materials, and innovative systems to detect gravitational waves. Key challenges include producing high-precision optical components, developing radiation-resistant materials, and maintaining ultra-stable laser systems. Inter-spacecraft alignment and environmental durability are crucial for performance, especially under harsh space conditions. Costly manufacturing processes and complex supply chains complicate production, but recent solutions such as additive manufacturing, active optics, and advanced metrology help overcome these challenges. The Challenges of Manufacturing Space Gravitational Wave Telescopes The Engineering Development Unit Telescope arrived at Goddard Space Flight Center in May 2024. This prototype was manufactured and assembled by L3Harris Technologies in Rochester. The primary mirror is coated in gold to reflect the infrared lasers and reduce heat loss from exposure to cold space, allowing it to operate optimally near room temperature. This development marks a significant advancement in astrophysical observations and cosmological studies.  Space gravitational wave telescopes, such as the Laser Interferometer Space Antenna (LISA), are designed to detect minuscule ripples in spacetime caused by gravitational waves. LISA, set to launch in the near future, will use a constellation of spacecraft spread over millions of kilometers to form a sensitive laser interferometer in space. This innovative approach enables unprecedented precision in measuring these ripples, requiring extreme stability and durability in space’s harsh environment. The advancements in LISA’s technology and engineering serve as a reference point for developments like the Engineering Development Unit Telescope, emphasizing the importance of sophisticated systems capable of operating in near-perfect isolation from external vibrations. As highlighted, the development of space gravitational wave telescopes is a monumental undertaking, requiring extreme precision, durability, and stability to function effectively in space’s demanding environment. Below, we explore the primary challenges involved in their manufacturing: Gravitational waves 1. High-Precision Optical Components Surface Accuracy: Telescope mirrors and lenses require nanometer-scale surface smoothness to minimize phase noise and optical distortion. Achieving such precision is a complex and labor-intensive process. Wavefront Aberration: To preserve wavefront integrity, optics must be fabricated with sub-wavelength tolerances. This demands meticulous attention to detail and cutting-edge technology. Large-Aperture Telescopes: Large apertures are necessary to transmit and receive laser beams across millions of kilometers. Achieving a lightweight yet precise optical assembly is a significant challenge. 2. Material Challenges Low Thermal Expansion Materials: Space environments experience dramatic temperature fluctuations, making it essential to use materials with minimal thermal expansion. A glass ceramic called Zerodur, along with options like ULE (Ultra-Low Expansion glass) or silicon carbide, provides the necessary stability. However, processing and shaping these materials remain a notoriously difficult challenge. Radiation Resistance: Components must endure cosmic radiation without degrading in performance. Advanced coatings and materials that can withstand long-term exposure are required. Drag-Free Test Masses: Test masses, often made of ultra-high-density and purity materials like gold-platinum alloys, must serve as inertial references. Manufacturing these to exact specifications is extremely challenging. 3. Ultra-Stable Laser Systems High-Purity Lasers: These telescopes rely on lasers with extremely narrow linewidths and unparalleled stability over long durations. Developing and maintaining such lasers is an intricate process. Frequency Stabilization: Stabilizing laser frequency to picometer-level precision requires complex cavity and modulation systems. Miniaturizing these systems for space use adds another layer of complexity. 4. Inter-Spacecraft Alignment Long-Distance Beam Steering: Aligning laser beams between spacecraft separated by millions of kilometers requires precise beam-directing systems and rigorous calibration. Pointing Stability: Maintaining nanoradian-level pointing accuracy demands highly stable and responsive control mechanisms to counteract dynamic orbital conditions. 5. Environmental Durability Thermal Control: Space telescopes must withstand a wide range of temperature gradients. Advanced thermal management systems are essential to prevent expansion or contraction of optical elements. Mechanical Vibrations: Vibrations during launch pose significant risks to delicate optical systems. Shock-absorbing designs and materials are critical for protection. Contamination Control: Dust, outgassing, and other contaminants can severely impact optical performance. A clean environment during assembly and operation is crucial. 6. Integration of Drag-Free Systems Free-Floating Test Masses: Test masses must be isolated from all contact with surrounding structures. Minimizing stray forces, such as electrostatic fields or thermal gradients, requires precise engineering. Electrostatic Positioning: High-precision sensors and actuators must maintain the test masses in perfect free fall without perturbation, demanding exceptional design and integration accuracy. 7. Large-Scale Assembly and Testing Ground Testing Limitations: Simulating zero gravity and long-baseline interferometry on Earth is practically impossible. Innovative testing setups are required to approximate space conditions. System Integration: Aligning optical, mechanical, and electronic components with high precision during assembly is an intricate and demanding task. 8. Cost and Scalability High Manufacturing Costs: Advanced materials, nanometer-scale fabrication, and rigorous testing processes make these telescopes exceedingly expensive to produce. Complex Supply Chains: Specialized components and precision manufacturing often involve multiple industries and countries, complicating logistics and increasing costs. Examples of Recent Solutions Additive Manufacturing: Enables the production of lightweight, complex structures with precise tolerances. Active Optics: Adaptive systems compensate for residual aberrations in real time, improving overall performance. Advanced Metrology: High-precision interferometers and wavefront sensors are used for testing and aligning components, ensuring unparalleled accuracy. Overcoming Challenges of Manufacturing Space Gravitational Wave Telescopes The challenges of manufacturing space gravitational wave telescopes highlight the intersection of cutting-edge technology and engineering ingenuity. By overcoming these obstacles, scientists and engineers are paving the way for groundbreaking discoveries in astrophysics, bringing us closer to unraveling the mysteries of the universe. Related Content

Key takeaways Optics debris detection is essential for managing orbital debris, which includes over 40,500 pieces of space debris larger than 10 cm traveling at high speeds. These collisions pose severe risks to satellites.  Advanced methods like laser ranging, LIDAR, and light sheet systems effectively track space debris.  Avantier offers custom optics solutions tailored for detecting orbital debris, ensuring precision and reliability for satellite payloads. Our expertise makes high-performance optics accessible for addressing this growing challenge. Orbital debris poses a very real risk to satellites and orbital spacecraft, and optics debris detection is the most effective way to mitigate that risk. Here we’ll examine how optical tracking, laser ranging and other methods can be used to determine the precise orbit of space debris. But first, why is space debris a problem? Orbital Debris: An Emerging Problem The low earth orbit was free of manmade objects until 1957, but since then, the number of small and large pieces of debris orbiting our planet has skyrocketed.  Today, there are an estimated 40500 pieces of space debris larger than ten centimeters, and 130 million greater than 1 mm.  Since these pieces of debris  travel at speeds in the order of kilometers per second, collisions can be catastrophic. It has been estimated that a small coin traveling at 10/km/s can deliver the same impact as a small bus, traveling at 100 km/hr. Even small pieces of space debris, then, are too dangerous to be ignored.  Proliferation of space debris in lower earth orbit has made optical debris detection a necessity. Optics Debris Detection Large pieces of space debris (with size greater than a meter) are cataloged and tracked from the ground using radar or simple optical methods. Radar provides a reliable method of following the orbits of space debris as they circle the earth, and can provide data accurate to within a few kilometers. This data can be relayed to the operators of any functional satellites who might be in danger of a collision.  Smaller pieces of space debris, though still dangerous, require more sophisticated optical methods or equipment that is mounted on LEO satellites. In one type of basic orbital debris detection sensor setup suitable for use in space, a permanent light sheet is generated using a low power laser and conic mirror. Such a system could be designed to weigh no more than 2 kg, and have a size of about 10 cm x 10 cm x 20 cm, making it suitable for incorporation into a wide variety of satellite systems. The scattering, reflection, transmittance or absorbance of light that happens when a piece of orbital debris intersects the light sheet could be detected by a CCD camera fitted with a wide angle lens. A wide range of information can be gleaned from this setup, including information on the size and light scattering properties of the object.  A basic optical debris detection sensor can provide information on debris passing through a light sheet propagated from an object in orbit. Precise orbital detection of mid-sized debris can also be achieved using carefully designed orbital laser ranging and LIDAR techniques. Often passive optical means and solar illumination are used to first recognize a piece of space debris, which is then illuminated with an intense ns-pulsed TOF laser. The receiver telescope is equipped with single photon detectors, capable of detecting backscattered photons. This detection method has been used to detect objects of as little as 10 cm in diameter, and typical ranging accuracy is about 3 m rms. Space Debris Detection at Avantier Avantier’s experienced optical design team has specialized in high performance custom optics, and  are familiar with the unique requirements of satellite payloads as well as the highly specialized optics needed to map space debris from the ground. Though high quality custom optical components and systems typically require a long turnaround and high budget, our in-house state of the art manufacturing equipment and dedicated team allow us to make these optics as accessible as possible to you, with as short a turnaround possible.  We can work with you from any stage of the process, whether you have a tested design ready to go or need help figuring out how to make your ideas work. Contact us today to place your custom order or set up an initial consult. References Bennet, Rigaut, Ritchie, & Smith. (2014). Adaptive Optics to Enhance Tracking of Space Debris. SPIE, https://spie.org/news/5541-adaptive-optics-to-enhance-tracking-of-space-debris Englert et al (2014). Optical Orbital Debris Spotter. Acta Astronautica, Volume 104 Issue 1, https://www.sciencedirect.com/science/article/pii/S0094576514002872 ESA (2024) Space Debris by the Numbers. https://www.esa.int/Space_Safety/Space_Debris/Space_debris_by_the_numbers NASA. (2018) Orbital Debris Management and Risk Mitigation. Academy of Program/Project & Engineering Leadership. https://www.nasa.gov/wp-content/uploads/2018/12/692076main_orbital_debris_management_and_risk_mitigation.pdf?emrc=e20460 Related Content