The reflector telescope is unique among telescopes because of its reflective design. Instead of using lenses to refract or bend light to form images, it uses a combination of curved surfaces and flat mirrors to reflect light for imaging.  Modern astronomical telescopes are typically reflector telescopes. Gregorian telescopes, Newtonian telescopes, and Cassegrain telescopes are all variations on the basic design. Here we’ll take a closer look at these three types of telescopes, and then go on to look at a reflector telescope produced with modern materials: the silicon carbide reflector telescope.  Three Types of Telescopes: A Closer Look Newtonian Reflector Telescope The original Newtonian reflector telescope was designed by Isaac Newton in 1668. This type of telescope is based on a primary mirror (parabolic surface) and a plane secondary mirror, and the light path is deflected to the side of the lens barrel. Newton Reflector Telescope Cassegrain Reflector Telescope If you need a long focal length with a short tube length, you may prefer a Cassegrain telescope, as first designed by Laurent Cassegrain in 1672.  The Cassegrain reflector telescope structure is usually a primary mirror (parabolic surface) and a convex secondary mirror, and the optical path passes through the central hole of the primary mirror. Cassegrain Reflector Telescope Gregory Telescope Another option is the Gregory telescope; a design that eliminates spherical and chromatic aberration.  The structure of the  Gregory reflector telescope involves a primary parabolic mirror surface and a concave ellipsoid secondary mirror. The quality of the image is dependent on the size of the aperture, and large versions of this design are used in many large telescopes like the Magellan telescopes, the Large Binocular Telescope, and the Vatican Advanced Technology telescope. Gregory Reflector Telescope Since all of these designs rely extensively on mirrors, it is particularly important to choose appropriate mirror materials. Mirror materials mainly include glass materials, low expansion metals, and ceramics. Glass materials have low thermal expansion coefficients and excellent optical properties, but their thermal conductivity and specific stiffness are poor. Metal materials have excellent thermal conductivity, but their thermal expansion coefficients are relatively large, and their surface shape accuracy is easily affected by temperature. Metal mirrors do have the advantage of high melting point, high hardness, high wear resistance, and oxidation resistance. What is a Silicon Carbide Reflective Telescope? If metal and glass both have significant downsides, what is the material of choice for large-format modern reflective telescopes? A modern material that has nearly ideal mechanical and physical properties: silicon carbide. Silicon carbide is a lightweight, stable compound produced by the reaction of carbon and silicon at high temperatures. When sintered or heat treated, these elements react to form a structure with ceramic characteristics.  Silicon carbide reflective telescopes, based on silicon carbide mirrors, are built to take advantage of the many advantages of this modern substrate. Lightweight, durable, and with good radiation resistance, these telescopes are pushing the boundaries of astronomical research worldwide. One example of a silicon carbide reflector telescope is the 4m Daniel K. Inouye Solar Telescope (DKIST), formerly known as the Advanced Technology Solar Telescope. This Gregory reflective telescope was designed to study solar magnetism and the solar winds and flares controlled by it, and utilizes a 4.24 meter primary mirror to do so. The secondary silicon carbide mirror has dimensions of 0.65 m, and the telescope has adaptive optics meant to correct for atmospheric distortions.  The LORRI (Long Range Reconnaissance Imager) on board the New Horizons spacecraft is another silicon carbide reflecting telescope. The design of telescope is Ritchey–Chrétien, a specialized type of Cassegrain reflector, and it features a main  silicon carbide mirror with a diameter of 208 mm. The effective focal length of the telescope is 2630 mmm, and  the imaging system can take pictures at very low light. It hs been used to successfully take high resolution images of Jupiter, Pluto, Arookoth, and the moons of Jupiter and Pluto. Advantages of the SiC Reflector Telescope But why, exactly, has SiC become the substrate of choice for high performance reflector telescopes? As an optical material for telescopes, silicon carbide has some important advantages. Lightweight: Silicon carbide material has high specific stiffness, which enables designers to reduce weight while maintaining high performance. This is particularly important for space telescopes, and can significantly reduce launch cost and energy consumption in orbit. High Precision: The surface accuracy of the silicon carbide mirror can reach nanometer level, which ensures the high-resolution imaging ability of the telescope. Good Thermal Stability: Silicon carbide material has low thermal expansion coefficient and high thermal conductivity, and can maintain stable performance at extreme temperatures. This makes it well suited for telescopes that need to operate in a wide temperature range, such as those working in space. Strong Radiation Resistance: Silicon carbide material has excellent radiation resistance to space particles, prolonging the service life of telescopes produced from it.  Large aperture: Silicon carbide can be used to manufacture large aperture mirrors, even up to 4 meters. Researchers are increasingly turning to silicon carbide when they require a material that is strong, durable, and suitable for high performance optics. Whether on the ground or in space, silicon carbide mirrors are well suited for use in high-performance telescopes.  Silicon Carbide Reflective Telescope Reflector Telescopes at Avantier At Avantier, we produce custom optics for a wide range of applications, including cutting-edge space exploration. If you need custom optics for your reflector telescope or simply would like some design help in getting started, we’d love to partner with you. Contact us today to place your custom order or schedule a free initial consult.  References Bae JI, Lee HB, Kim JW, Lee KM, Myung-Whun K.  Development of a Silicon Carbide Large-aperture Optical Telescope for a Satellite.  Korean J. Opt. Photon. 2022;33:74-83.  https://doi.org/10.3807/KJOP.2022.33.2.074 Rimmele, The unique scientific capabilities of the Advanced Technology Solar Telescope, Advances in Space Research, Volume 42, Issue 1, 2008, Pages 78-85, ISSN 0273-1177, https://www.sciencedirect.com/science/article/pii/S0273117708001129 Robichaud et a.  “Silicon carbide optics for space and ground based astronomical telescopes”, Proc. SPIE 8450, Modern Technologies in Space- and Ground-based Telescopes

Key Takeaways Avantier specializes in high-precision microscope objectives. Our process involves detailed optical and mechanical design, precise lens fabrication, meticulous structural part machining, careful lens group assembly and debugging, rigorous installation and adjustment, and final re-inspection and secure packaging. Our state of the art design and manufacturing processes ensure high-performance objectives for diverse applications. Introduction to Manufacturing High Resolution Microscope Objectives With over two decades of experience in optical engineering and manufacturing, our company specializes in the design and production of high-precision microscope objectives. Our portfolio encompasses a wide range of standard and specialized objectives, from conventional 2X to 100X flat field designs to advanced supercomplex metachromatic objectives. This article provides a detailed technical overview of our manufacturing process, focusing on the production of a 20X microscope objective as a representative example.  Optical Design The process of designing a new objective begins with meticulous optical design, driven by customer specifications and application requirements. Requirement Analysis: Optical engineers analyze customer-defined parameters, including usage requirements, lens specifications, and acceptance criteria. Design and Simulation: Utilizing advanced optical design software (e.g., ZEMAX), engineers develop and optimize the optical system. Tolerance Analysis: Critical to manufacturability, engineers refine tolerances for optical components, ensuring ideal performance within production capabilities.Engineering Drawings: Aided by state of the art design software,  the team generates detailed engineering drawings for all optical elements. ZEMAX Screenshot of 20X Optical Design   Architectural Design Even as the optical design process is underway, structural engineers develop the mechanical design of the objective. Mechanical Requirements: Structural design factors in all customer-specified mechanical parameters, including external dimensions and interface threads. Manufacturing Constraints: Engineers optimize structural tolerances, surface treatments, and material selection based on production processes. Engineering Drawings: Comprehensive engineering drawings for all structural components are created. CAD Screenshot of 20X Objective Structural Design Lens Processing When the design of the objective is complete, it is time for fabrication to begin. The fabrication of high-quality lenses is a multi-stage process requiring precision and control. Process Planning: Process engineers generate detailed process diagrams, including lens drawings, tooling requirements, and manufacturing sequences. Material Preparation: Raw optical materials are cut to precise dimensions according to process drawings. Grinding: Coarse Grinding: Initial shaping of the lens blank is done using coarse grinding methods. Fine Grinding: Precise shaping of the lens radius (R value) and thickness is accomplished by fine grinding that may be computer-guided. Lens Grinding Polishing: After the lens is shaped, the required surface finish is achieved through various polishing techniques (classical, low throw, high throw). Lens Polishing Edging: The outer diameter of the newly polished lens is then ground to specified dimensions. Lens Edging Inspection: After the edging is finished, rigorous testing using interferometers, projectors, micrometers, and calipers is done to verify lens dimensions and surface quality. Lens Outer Diameter Test Cleaning: Ultrasonic cleaning is used to remove contaminants, and this cleaning is followed by cleanliness inspection. Coating: For many lenses, the next step in the process is the application of optical coatings using vacuum deposition techniques to meet spectral requirements. Coating Test Cementing: Bonding multiple lens elements is accomplished using UV-curable adhesives, with precise centering adjustments. Blackening: Application of black ink to lens edges is done to minimize stray light. Lens Edge Blackening Final Inspection and Storage: When the edging is complete, we run a comprehensive inspection of lens parameters and surface cleanliness, followed by packaging and storage in a controlled environment. Lens Surface Wipe Inspection Structural Parts Processing Producing a microscope objective also involves the fabrication of mechanical components, which  is performed using precision machining techniques. Process Planning: Process engineers develop detailed process drawings and tooling requirements. Material Preparation: Raw materials are cut to specified dimensions. Machining: Precision machining is done with lathes, milling machines, and other equipment. Metal Working Workshop Inspection: All parts are subject to dimensional and geometric verification using coordinate measuring machines (CMMs) and other metrology equipment. Surface Treatment: After inspection, surface treatments such as anodizing, sandblasting, and electroplating are done as required. Final Inspection and Storage: Comprehensive inspection and packaging is done in a controlled environment. Mirror Group Assembly and Debugging: The assembly of lens elements into optical groups is a critical step. Assembly Techniques: Two important techniques are employed in assembly: point glue repair and optical axis turning. Point Glue Repair: Point glue repair involves precision alignment and bonding using UV-curable adhesives. Semi-Automatic Glue Repair Machine Optical Axis Turning: Precision machining is done to ensure concentricity and perpendicularity of lens elements. Lens Installation and Adjustment: Objective Debugging: Assembly and adjustment of the objective lens is accomplished using a microscope frame and star target observation. Objective Point Adjustment Perfect Star-Dot Image Image with Coma Aberration Resolution Testing: A resolution target is used to evaluate and test the objective resolution. Resolution Target Image Under 20X Objective Focal Length Adjustment: The objective lens focal length is adjusted through precision machining. Re-inspection and Packaging: Before an objective lens leaves our factory, final quality control and packaging ensure product integrity. Re-inspection: Comprehensive testing of assembled objectives is done using star target observation and MTF testing. Objective Lens MTF Detection Packaging: The objective is securely packed to ensure comprehensive protection during shipping and storage. 20X Objective Packaging Carton 20X Objective Packaging Bottles Manufacturing High Resolution Microscope Objectives The manufacturing of high precision microscope objectives is a complex and demanding process requiring expertise in optical design, precision machining, and assembly. Our company’s commitment to quality and continuous improvement ensures the delivery of high-performance objectives for a wide range of applications. Related Content

KeyTakeaways LiDAR for Robotics: LiDAR (Light Detection and Ranging) enables precise mapping by using laser light, offering reliable vision even in darkness or challenging environments.   1D LiDAR: Measures distance using a single laser pulse, ideal for collision avoidance, UAV altitude measurement, and industrial inspection.   2D LiDAR: Scans a plane by rotating, improving spatial awareness for security, motion detection, and autonomous vehicles.   3D LiDAR: Creates full 3D maps, simplifying setup and replacing multiple sensors.   Advanced LiDAR: Includes Flash, OPA, and MEMs LiDAR for enhanced imaging. A LiDAR sensor for robotics is more than simply another mechanical imaging system. LiDAR, short for Light Detection and Ranging, uses light in much the same way radar uses radio waves— to create a highly accurate, highly reliable map of surrounding objects. Since it relies on its own laser light source rather than ambient light, it can “see” even in darkness and when the atmosphere is opaque to visible light. Less prone to interference than ultrasonics, it is well suited to robotic vision, especially where precision and reliability are at a premium.  Advances in robotics promise more effective systems with the potential for more autonomy, and it is in these effective, semi-autonomous systems that require minimal guidance that foul-proof vision systems are becoming of more and more importance. Developments in LiDAR sensors have made this technology, once inaccessible except to the best funded research, well within the reach of any industrial or research application. In this article we’ll look at several different types of LiDAR sensors— 1D, 2D, and 3D sensors— and how they function in various robotic applications.  LiDAR sensors for robotics can be used to provide reliable information on the environment in which a robot is used 1D LiDAR Sensors A one-dimensional LiDAR is a compact economical system with one basic function— to measure the distance between it and an object directly in front of it by line of sight. It accomplishes this by sending one-directional pulses of laser light and detecting the time of flight when the pulse is reflected back. This can be converted to an incredibly precise, real time distance measurement.  One dimensional LiDAR systems can be used for dependable collision avoidance as well as for altitude measurement on UAVs, basic surveillance, industrial or agricultural inspection,  or quality control purposes. These systems are sometimes referred to as laser range finders.  A 1 D LiDAR sensor for robotics is a compact, affordable way to avoid collisions or calculate altitude 2D LiDAR Sensors 2 Dimensional LiDAR  systems are one step up from 1D LiDAR, both in expense and size, but they are still an economical option compared with 3D LiDAR and they provide significantly more information than is possible with a 1D model. The basic core of a 2D LiDAR sensor is the same as that of the 1D version— a laser coupled with TOF sensor— but, unlike the 1D version, this one spins around at a constant rate on what is essentially a turntable, providing data on every point in the plane.  2D LiDARS can be used for many of the same functions 1D LiDAR sensors are used for and provide a significant upgrade in the amount of information received.  They are often used in security applications and  motion detection, and can be used on autonomous cars. The update rate of a 2D LiDAR generally depends on the rate at which the turntable spins. It is also important to realize that the spatial resolution of objects will decrease as the distance from the LiDAR sensor decreases as the sensor itself is limited in angular resolution.  3D LiDAR Sensors 3D Dimensional LiDAR  systems are more complex and significantly more expensive to produce, but they offer a complete 3D view of the environment in which they are placed. They are designed to scan both horizontally and vertically and produce detailed 3D maps of their surroundings.  Aside from their comprehensive imaging output, one benefit of these sensors is the ease of use for the end user. Setup for a 3D LiDAR sensor is often simpler than putting together an effective  imaging system using 2D and 3D LiDAR systems, and a single 3D sensor can take the place of multiple 2D and 1D sensors.  More Types of LiDAR Not all types of 2D and 3D LiDAR rely on mechanical systems and turntables. One alternative approach is Flash LiDAR, which uses flashes of light that are then returned to a 2D detector array. Optical phase arrays (OPA) LiDAR systems use several sensors, placed near each other and firing off not simultaneously but in sequence. Another type of 3D LiDAR, Microelectromechanical system (MEMs) LiDAR, uses a multitude of tiny mirrors to direct laser pulses to cover a wide area without any rotation involved.  LiDAR Sensors at Avantier At Avantier, our engineering and design teams are at the forefront of optical development, and we’re pushing the envelope each and every day. Working closely with our clients, we design and produce cutting-edge optical systems that challenge the status quo and bring you where you need to be. If you’d like a custom optics for your robotic application, get in touch with us today.  References  Mochurad, Lesia, Yaroslav Hladun, and Roman Tkachenko. 2023. “An Obstacle-Finding Approach for Autonomous Mobile Robots Using 2D LiDAR Data” Big Data and Cognitive Computing 7, no. 1: 43. https://www.mdpi.com/2504-2289/7/1/43 Royo, Santiago, and Maria Ballesta-Garcia. 2019. “An Overview of LiDAR Imaging Systems for Autonomous Vehicles” Applied Sciences 9, no. 19: 4093. https://doi.org/10.3390/app9194093 Troyer, Tyler et al. 2016. Inter-row Robot Navigation using 1D Ranging Sensors, IFAC-Papers OnLine, Volume 49, Issue 16, Pages 463-468, ISSN 2405-8963, https:/www.sciencedirect.com/science/article/pii/S2405896316316470 Related Content

Key Takeaways Semiconductor manufacturing requires high-precision optical lens assemblies.  Custom objectives face challenges like miniaturization, thermal instability, and cost.   Semiconductor lens assembly solutions include advanced fabrication, adaptive optics, and thermally stable materials.   Key design considerations are optical performance (NA, chromatic correction, FOV), material selection (low dispersion, high transmittance), and specialized coatings.   Meeting these demands requires a collaborative approach and cutting-edge manufacturing to ensure reliable performance in harsh fab environments. In today’s rapidly advancing technological landscape, semiconductor manufacturing pushes the boundaries of precision and miniaturization. Custom objectives, essential optical components within sophisticated imaging systems, are at the heart of this progress, enabling. These intricate optical lens assemblies enable critical processes like photolithography, wafer inspection, and metrology. This summary delves into optical design considerations for these custom optical systems, exploring the challenges and highlighting innovative assembly solutions. From high NA microscope objectives to complex multi-element lenses, achieving optimal system performance requires careful attention to optical performance, material selection, coating requirements, and robust manufacturing capabilities. Microchip semiconductor manufacturing Design Considerations for Custom Objectives: When designing custom objectives for semiconductor manufacturing and inspection, there are three areas that need special attention: optical performance, materials selection, and coating requirements. Optical PerformanceKey parameters include: Numerical Aperture (NA): High NA (often >0.95) is essential for sub-wavelength resolution. Chromatic Correction: Objectives must perform consistently across multiple wavelengths (e.g., DUV, EUV). Field of View (FOV): Balancing high resolution with a wide FOV is crucial for throughput. Aspheric or freeform lenses may be required. Material Selection:Materials must exhibit: Low Dispersion: Minimizes chromatic aberration. High Transmittance: Maximizes light throughput, especially in UV/DUV. Environmental Stability: Resistance to temperature variations, chemicals, and radiation. Examples include fused silica and CaF2. Coating Requirements:Essential coatings include: Anti-Reflection (AR): Minimizes light loss and enhances contrast. Hard Coatings: Protect lens surfaces from damage. Bandpass Filters: Isolate specific wavelengths for metrology and inspection. Challenges and Solutions: Miniaturization, thermal stability, cost, and environmental challenges can complicate the design process and require carefully crafted solutions. Miniaturization and Complexity: Smaller devices require increasingly complex lens assembly designs and tighter tolerances. Challenge: Achieving nanometer-level accuracy in lens alignment and managing higher-order aberrations in high-NA systems. Solution: Adaptive optics, freeform lens technologies, and advanced fabrication techniques (e.g., diamond turning, computer-controlled polishing). Thermal Stability: Semiconductor environments experience thermal fluctuations that can degrade lens performance. Challenge: Maintaining optical performance despite temperature variations. Solution: Thermally stable materials (e.g., fused silica, ULE glass), athermal designs, and active cooling systems. Cost Considerations: Developing high-end custom objectives is expensive, especially for low-volume production. Challenge: Balancing performance with cost effective solutions. Solution: Collaborative development with optical suppliers, standardized modular designs, and rapid prototyping. Environmental Challenges: Semiconductor fabs present harsh environments with contaminants, vibrations, and chemicals. Challenge: Protecting lenses from these factors. Solution: Protective coatings, vibration isolation systems, and purge systems can maintain a clean optical path. The Future of Semiconductor Lens Assembly Solutions Designing custom objectives for semiconductor applications demands a multifaceted approach, taking into account the complex interplay of optical, material, and environmental factors. Continuous innovation in design, fabrication, and environmental control is necessary in order to meet the stringent quality standards and performance requirements of this industry. Addressing the challenges posed by miniaturization, thermal instability, cost constraints, and harsh environments requires a collaborative effort, leveraging the expertise of a skilled engineering team with advanced manufacturing capabilities.  Optical advances such as  active alignment techniques and a wider range of optical lens assembly types are crucial for ensuring the reliable performance of optical systems in semiconductor manufacturing. Avantier, an ISO 9001 certified company, offers high NA microscope objectives and customized solutions with cutting-edge technologies, manufactured and tested to the highest quality standards. Contact us today for your next project in semiconductors or any other industry that requires high-performance optical systems.  Related Content

Key Takeaways Custom optical objectives, especially those with high NA, are crucial for advanced semiconductor manufacturing.  These objectives enable precise photolithography, metrology, and defect inspection for sub-5nm nodes.  While offering high precision, improved yields, and enhanced resolution,  custom  optics also pose challenges in design, manufacturing, and cost.  Emerging trends like meta-lenses and AI-assisted design are driving further innovation. Custom optical objectives are crucial for semiconductor manufacturing and inspection, enabling the precision needed for advanced technologies. High numerical aperture (NA) objectives are particularly important for achieving the resolution required for sub-5nm feature sizes. The semiconductor industry relies heavily on a complex and interconnected supply chain to deliver the cutting-edge products and systems that power modern devices. Within this ecosystem, specialized companies that focus on the design and manufacture of high-precision optical components play a crucial role. Key Applications Photolithography: High NA objectives focus UV or EUV light onto wafers with nanometer precision, creating intricate circuit patterns. They require high transmission at specific wavelengths (e.g., 193nm or 13.5nm), exceptional thermal stability, and minimized aberrations. Metrology and Inspection: Custom objectives can enhance tools like CD-SEMs, optical profilometers, and defect inspection systems. High NA lenses improve resolution and depth of field for precise dimensional measurements and sub-nanometer defect detection. Laser-Based Processes: Custom-built objectives ensure accurate beam focus and uniform energy distribution. They also mitigate thermal damage in applications like laser annealing, drilling, and patterning. Wafer inspection in the semiconductor manufacturing process Challenges in Design Designing a custom objective for specific applications is  a complex process. Thermal stability is often of paramount importance due to the heat generated by high-power light sources. Precision manufacturing is essential, as even minor imperfections can degrade performance. Material selection is critical for optimal transparency and minimal birefringence at specific wavelengths. Cost and time constraints may also pose significant hurdles. Advantages of Custom Objectives: Given numerous design and manufacturing challenges, why choose custom objectives?  A custom-designed and manufactured objective can provide significant performance improvements, and you’re likely to see a number of advantages as you incorporate these objectives into your system: High Precision and Accuracy: Sub-nanometer accuracy is achievable, enabling features down to 5nm and below to be patterned or inspected. Aberration correction can be optimized. Improved Yield and Defect Detection: Early defect detection and precise overlay control lead to high yields in advanced semiconductor nodes. Enhanced Resolution: High NA lenses enable smaller feature sizes for EUV lithography and nanometer-scale defect detection. Thermal Stability and Environmental Control: Low-expansion materials and controlled environments ensure consistent performance across a wide range of temperatures and environmental conditions. Flexibility and Tailored Solutions: Custom designs,  including unique substrates, geometries, and manufacturing processes, meet the needs of specific applications. Supporting Advanced Technologies: Integration of meta-lenses and AI-assisted design further improves performance. Limitations of Custom Objectives: Although custom objectives are invaluable for many semiconductor manufacturing and inspection applications, they do have their downsides. Limitations of custom objectives include: High Costs: Design, prototyping, and testing are expensive and time-consuming. Manufacturing Complexity: Precise alignment during assembly is challenging. Long Development Time: Extended design and manufacturing time impact time-to-market. Limited Scalability: Custom optics often have a high per-unit cost due to low production volumes. Maintenance: Specialized maintenance and servicing are typically required for made-to-order optics. Material Limitations: Finding suitable materials for high-NA objectives under extreme conditions can be challenging. Contamination Sensitivity: EUV systems are highly sensitive to contamination. High NA Systems in Semiconductor Applications High NA objectives are essential for: EUV Lithography: Achieving sub-5nm feature sizes for advanced nodes. Defect Detection: Detecting critical sub-nanometer defects. Metrology Tools: Analyzing surface and subsurface features. Emerging Trends: Meta-Lens Integration: Ultra-thin, high performance systems. AI-Assisted Design: Accelerating development through optimized design parameters. Sustainability: Energy efficiency and environmentally friendly materials. Advanced Node Technology: Enabling next-generation nodes. Photonics for Semiconductors: Driving efficiencies in various processes. Avantier’s High NA Solutions for Semiconductor Applications Custom objectives, particularly high NA systems, are indispensable for semiconductor manufacturing and inspection. Cutting edge optical research promises further advancements, enabling the optics industry to fully meet the evolving demands for semiconductor technology. Avantier’s products and services are specifically tailored to meet the exacting demands of this dynamic industry, providing the critical optical solutions needed for leading-edge semiconductor manufacturing and inspection equipment. We offer high NA microscope objectives and customized solutions with  state-of-the-art technologies.  Contact us today to discuss your next projects and find out more about how we can partner with you. Related Content