Optics for drones with infrared sensors create an advanced optical system for enhanced surveillance in various drone applications.
Optics for drones with infrared sensors create an advanced optical system for enhanced surveillance in various drone applications.
The advantage of optical domes is protecting custom domes and optical components from underwater pressure.
The Germanium Optical Dome ensures optical clarity for drones by protecting optical instruments and maintaining their performance.
Key Takeaways Optics for LiDAR and sensing are crucial for a LiDAR system, which uses a laser to measure distances by calculating the time it takes for light to return—essentially answering what is LiDAR. LiDAR technology has advanced from its early use in satellite tracking to applications in mapping and autonomous vehicles. Modern LiDAR systems utilize various lasers, including 1550 nm Er-doped fiber lasers and 534 nm or 1064 nm lasers for different environments. Custom optics, including bandpass filters, are essential for optimizing LiDAR performance and controlling background noise. Advancements and Accessibility in Optics for LiDAR Technology Optics for LIDAR and sensing are far more affordable today than they were just ten years ago, and the technology is currently accessible to almost anyone. In fact, if you carry around a newer iPhone Pro, you’ve got your own mini LIDAR system, though it may be there more as a novelty than for any practical purpose. Light Detection and Ranging (LiDAR) was first introduced in 1961, not long after the laser was invented, as a method to track satellites by measuring the time it took for a laser signal to return. A LiDAR altimeter was used to map the surface of the moon in 1971, but the device was enormous, expensive, and gave subpar results. Today, improved technology is used to create maps, elucidate archeological sites, and provide the vision needed for autonomous vehicles. But that’s just a few of the thousands of uses of this key photonic technology. But just what is LiDAR, and what optics are needed for a successful, high performance system? That’s what we’ll look at here. First questions first: what is LiDAR, and how does it work? What Is LiDAR? A LiDAR system is the photonic analagy of radar. Light from a precisely directed, rapidly firing laser is bounced off an object or terrain. On its return, time of flight calculations give the exact distance between two points, information that can be used to create detailed 3D models or topographical maps. LiDAR mapping is derived from time of flight calculations on laser light. Laser for LiDAR A LiDAR system can be designed to use UV, vis, or NIR lasers. The laser selected depends on the objects being surveyed and the environment the imaging takes place in. Non-scientific applications typically use 600-1000 nm lasers, but care must be taken since these wavelengths can be damaging to the human eye. Er-doped fiber 1550 nm lasers are the preferred option for many military applications, as they are both relatively eye-safe and not visible to night vision goggles. They are also used for topography mapping, measuring distance, and obstacle avoidance, but they rely on InGaAs sensors and are therefore more expensive to use LIDAR based on lower-wavelength lasers. LiDAR can use eye safe Er -doped fiber 1550 nm lasers to generate topographic maps like these. For underwater and bathymetry applications, you need a laser that has good transmission in pure water as well as limited backscattering from the small particles that will be encountered in seawater. we recommend 534 nm frequency-doubled diode pumped YA lasers. These lasers penetrate water with minimal attenuation. For airborne topographic mapping, 1064 nm diode-pumped YAG lasers are preferable. Other key laser parameters key to your LiDAR setup include pulse repetition rate, laser power consumption, and beam divergence. You will also need to choose between flash LiDAR, in which the whole field of view is illuminating at once, or more conventional scanning LiDAR which goes over the field of view point by point. Controlling the Spectral Width with Bandpass Filters When laser at 1064 nm is used for long range airborne LiDAR systems, one challenge to be overcome involves the high levels of background noise created by radiance from the sun. Signal to noise ratio can be increased by fitting the LiDAR receiver with a narrow bandpass filter. Harsh environmental conditions necessitate a robust filter that can perform consistently and reliably. Multilayer thin film coatings that provide transmission narrowly matching the laser wavelength are often chosen. When narrow linewidth meter-oscillator power-amplifier (MOPA) based pulsed lasers are used, the central wavelength is determined by the seeding laser pulse but is affected by numerous diode conditions (temperature stabilization, drive current, and pulse repetition rate, among others). Wavelength control is no longer simple, and in this situation a bandpass filter should be chosen with a band wide enough to allow for any expected wavelength shifts. Custom LiDAR Systems At Avantier, we focus on custom optics that are tailor-made to meet our customers’ exact specifications. LiDAR is one field where there is no one size fits all, and if you try to fit a ready-made solution into your application you’re sure to run into frustration. A better option is to work with our optical engineers and designers to order a system custom-made to your specifications. Sound intriguing? Contact us today to start exploring your possibilities or set up an initial consult with one of our experts in LiDAR technologies. Related Content
Micro prisms are designed with precision to handle specific wavelengths and coatings, optimizing performance in any optical system.
C-Lens manufacturing demands high-quality micro lenses with excellent surface quality and cost-effective production methods.
Key Takeaways Micro-optics, including lenses used in biomedical sensors and optical fibers, enable advanced miniaturized technologies. These tiny components enhance consumer products and biomedical devices with their precision. Manufacturing methods include traditional techniques, photoresist reflow, and soft lithography. Micro-optics are often integrated into microsystems or produced in arrays for various applications. The Power of Micro-Optics Can a lens be mounted on a surface smaller than the head of a pin, or the full power of complex optical devices be condensed into a package smaller than a fingernail? That’s what micro-optics are about. Microlens Arrays https://youtu.be/4GwimAIed5c?si=yOkcOMCSr2YDZSoH A micro-optic is an optical component or array between a few micrometers and a millimeter in size. These miniature optics are taking an increasingly central position in modern manufacturing as advances in manufacturing make them more accessible to consumer needs. Once the exclusive domain of specialized defense and research projects, cost-effective micro-optics are now to be found in consumer products everywhere, from fiber optical communication systems to smart phones to biomedical devices. Here we’ll look at a few examples. Biomedical Applications of Micro-Optics Biomedical sensors are one important use of micro-optics. The core of these sensors is typically a MOEMS, or micro-opto electromechanical system, which incorporates both micro-optics, tiny electronic parts and other mechanical components to create an robust, lightweight system that can be integrated into the human body. The MOEMS used in biomedicine are composed of micoroptics combined with electronics and mechanical components These systems must be carefully manufactured for optimal strength, wear resistance, stiffness, and fatigue resistance. They must also be optimized for their exact function and the environment they will find themselves in the body. For instance, a 3D intraoral scanner, used within the back, used on photonics MEMS (micro-electronic-mechanical systems) technology can be used to map the 3D image needed for accurate dental restoration. Back pain is difficult to diagnose, but a FBG sensor can be incorporated into the intervertebral disc to provide a better understanding of pressure distribution in the intervertebral disc, and improve clinical diagnostic of disc strain. What about the inner-eye pressure that causes glaucoma? Intraocular pressure build up can be monitored with a micro-sized optical implant using a flexible photonics crystal membrane. A micro-optic sensor can be used to determine the cause of back problems. Manufacturing of Micro-Optics Some micro-optical parts are manufactured in nearly the same way as their non-micro counterparts, though their small size presents unique challenges and requires extra care in manufacturing. The small beam collimator lenses for laser diodes are an example of micro-optics which are usually manufactured with traditional techniques. These tiny lenses may one or two millimeters across. The ultra-tiny components needed for optical data transmission, though, are not practical to make with traditional methods. A single optoelectronic chip may include microlasers, tiny photodetectors, and a variety of lenses or beam collimators. One manufacturing method used for these very small micro lenses is called photoresist reflow. A photoresist material is deposited on a circular area with a tiny diameter, typically in the tens of microns. When the device is heated, the photoresist melts. Surface tension gives the melted photoresist a well defined surface with a curvature that is nearly spherical. Replication techniques such as injection molding, hot embossing, UV casting involve first manufacturing a master structure, then mass producing a large number of identical tiny optics. Soft lithography, also known as micro contact printing, is another option for microptic manufacture. Here lithograph is applied to optical materials such as a wafer, and surface tension provides the smooth aspheric surface desired. One type of soft lithography is nano imprint lithography (NIL), which uses UV light and special stamps to transfer lens patterns onto prepared optical polymer material. Thousands of lenses can be manufactured on a single 8 inch substrate. What about if more flexibility is needed? Then direct laser writing may be a possibility. This method can be used to fabricate even complex three dimensional microstructures, and the possibilities it might lead to are currently being explored. Most of these tiny micro-optics are not usually produced and sold individually. They might be inserted directly into their optical microsystems, which can then be combined into micro-electronic-mechanical systems (MEMS) with unique functions. They can also be produced in the form of one or two dimensional arrays. When necessary, laser-based processes can be used to insert a single microlens on the end of an optical fiber or other micro component. single microlens on the tip of a optical fiber Have we piqued your interest? Contact us today if you’d like to know more about micro-optics and how we can produce custom micro-optics for your application. Related Content
Key Takeaways: Molded glass domes, including optical glass domes with flanges, offer superior optical clarity and durability. Common issues include distortion, haziness, and reduced transmission. Long-term challenges involve radiation degradation, thermal failure, and mechanical stresses. Ideal dome selection requires assessing application needs, manufacturing methods, and material choices. Optical Dome with Flange In the fascinating world of optical camera systems, achieving transparency is only the first step. What truly distinguishes flanged camera optical glass domes, however, is their remarkable optical invisibility. Even the most discerning eye or camera lens cannot detect their presence. In optical terms, this achievement is described as near-zero “wavefront error,” which represents a new standard of clarity and precision. At the pinnacle of optical camera dome systems, our solution seamlessly integrates optical camera domes with proprietary flange mounting technology. Not only are these domes rugged and durable, but they also easily adapt to existing systems, promising resilience in even the harshest environments. With the right choice of flanged optical glass domes that can withstand pressures up to thousands of PSI, camera systems are being ushered into a new era of optical clarity and durability. Common issues with flanged molded camera glass domes: Overall Distortion This type of distortion arises from poor glass dome design, variations in wall thickness, and material inhomogeneity. For camera systems, distortion becomes even more problematic. Localized Distortion & Speckle These issues result from mold marks, bubbles, pits, scratches, and other local defects. Haziness Haziness occurs due to micro-surface abrasion, devitrification, and low-quality bulk material. Reduced Transmission Poor-quality material leads to signal attenuation, exacerbating reduced transmission. Color Shift & Chromatic Aberration Non-neutral material color filtering and color dispersion cause color shifts and aberrations. Parallax Error This error stems from overall system design, including camera positioning. Fresnel Reflections (Fresnel Losses) A natural surface effect that reduces transmission and causes multiple images and signal loss. However, good system design and anti-reflective coatings can mitigate this. Mounting Issues: A poorly designed flange mounting system poses risks to costly equipment. Rayotek’s flanged glass domes, with a proven track record, are securely mounted and fully sealed against hostile environments. Long-term reliability issues In designing a flanged molded optical glass dome: Radiation (Light) Degradation Prolonged exposure to sunlight and intense lighting can lead to yellowing and solarization of dome materials. Thermal Failure & Degradation Plastic domes become brittle and lose strength and optical clarity when subjected to excessive heat. Glass domes, if made from the wrong material, can crack or even explode due to thermal shock. Mechanical Stresses Impacts, explosions, abrasion, and other environmental hazards can compromise both optical and mechanical performance. Flange Seal Failure The strength of a mounted glass dome relies on the seal to the flange. Equally critical is the reliability and durability of the seal between the housing and the glass dome. Addressing the quality and reliability issues mentioned above encompasses solutions ranging from straightforward, cost-effective measures to more complex and expensive ones. It’s crucial for designers to grasp the essential requirements of the application and to be aware of the constraints posed by imaging and image processing equipment. Avantier’s approach involves understanding the requirements and limitations, developing tailored solutions, optimizing technology usage, providing value to customers, and continuously improving its offerings to overcome quality and reliability issues effectively. How to Select the Ideal Glass Dome? When selecting the optimal glass dome for your specific application, it’s crucial to consider several key factors. Understand Application Requirements: Before choosing a dome, thoroughly assess your application needs to avoid unnecessary expenses. Overkill in specifications often translates to overcost. Determine the essential features required without compromising performance. Performance Limitations of Imaging System: Ensure that the dome does not impede the imaging system’s functionality. However, avoid going beyond what is necessary to prevent overspending. Align the dome’s specifications with the imaging system’s capabilities. Manufacturing Method Impact: The method of manufacturing significantly affects both optical and mechanical performance, as well as manufacturing costs. Ground and polished domes are precise but expensive. Plus, the manufacturing process can be time-consuming. Molded glass domes can be press-molded or slumped. Press-molded domes may exhibit mold marks and distortion, making them better-suited for non-optical applications. Slump-molded glass domes offer superior surface quality compared to ground and polished domes at a lower cost. Material Selection: The chosen material greatly influences optical performance and durability. Plastic is inexpensive but prone to degradation and scratching over time, particularly under harsh conditions. Slump-molded glass domes are typically made from high-quality glass, offering durability and optical clarity. Flange Material and Sealing Process: Select appropriate flange materials by considering factors like temperature, pressure, chemical exposure, and radiation. We provide specialized expertise in sealing processes tailored to specific applications, ensuring optimal performance without unnecessary costs. Conclusion Choosing the appropriate glass dome for your application requires a thorough understanding of your specific requirements to effectively balance performance and cost. Factors such as manufacturing method, material selection, and flange sealing play crucial roles in ensuring optical clarity, durability, and resilience in various environments. Avantier is committed to excellence in crafting flanged camera optical glass domes. We utilize premium materials and innovative manufacturing processes to ensure unparalleled optical integrity and long-term reliability. By prioritizing these key considerations, you can confidently choose the optimal glass dome solution for your imaging system needs. Related Content
Optical domes protect optical systems and maintain optical performance even under high pressure conditions.
Laser Metrology uses laser interferometers with specific wavelengths and semi-reflectors for precise measurements.