Aspherical Lenses

Hyperion Optics’ manufacturing equipment expand our aspherical products’ deliverability to LWIR applications, from high precision VIS imaging systems to infrared athermal lenses, we are able to process on optical glasses and infrared materials such as Germanium, Zinc Sulfide, Zinc Selenide, Calcium Fluoride, Chacolgenide glasses etc.

We insist to simulate every aspherical equation and specs from customer’s inquiry to make sure we are capable of delivery, and provide suggestions based on our study and understanding. For complicated design, we are willing to run trial test on H-K9 glass to verify your design’s feasibility, with profiler map provided for customer’s reference.

Our aspherical lenses manufacturing cost also assists our customers to use aspherical surfaces in their design to achieve better system performance or compactable goal, meanwhile keep pricing competency in the market.

We are able to work on optics LRIP project (low ratio initial production) , such as 5-10 pieces for optical feasibility study, to volume 200 pieces to 500 pieces production. Let us know your delivery plan; we can work on precise part dispatch planning.

Asphere Lenses

Due to the more complex surface profile of asphere which significantly reduces or eliminate optical aberrations as compared to the simple lens, Aspheric lenses have at least one surface that is not a true sphere,It has been more widely exploited in the lens optical design stage.

IR Asphere Lenses

At Hyperion Optics, we work with various infrared materials. Besides spherical parts, with increasing demand of IR aspheric components, designers are more likely to use aspheric parts in LIRP projects to meet relatively reliable performance meanwhile to decrease the element quantity within the system. Our aspheric component manufacturing capability covers 0.8 micron up to 12 micron for your infrared application from combination of materials needed in order to achieve your application expectation.

Diffractive Optical Elements

Diffractive optical elements (DOEs) shape and split laser beams in an energy-efficient manner. You can implement a broad range of applications with minimal light loss – examples of diffractive micro optics can be found in production facilities for laser material processing, in medical laser treatments and diagnostic instruments, in areas such as lighting, printing technologies, and lithography as well as in measuring and metrology systems. DOEs are used to pattern light in work areas for custom illumination. Hyperion Optics offers DOEs for all wavelengths across the spectrum.

Parabolic Mirrors

Parabolic reflectors are used to collect energy from a distant source (for example sound waves or incoming star light). Since the principles of reflection are reversible, parabolic reflectors can also be used to focus radiation from an isotropic source into a narrow beam. In optics, parabolic mirrors are used to gather light in reflecting telescopes and solar furnaces, and project a beam of light in flashlights, searchlights, stage spotlights, and car headlights. In radio, parabolic antennas are used to radiate a narrow beam of radio waves for point-to-point communications in satellite dishes and microwave relay stations, and to locate aircraft, ships, and vehicles in radar sets. In acoustics, parabolic microphones are used to record faraway sounds such as bird calls, in sports reporting, and to eavesdrop on private conversations in espionage and law enforcement.

Cylindrical Lenses for customizition

Hyperion Optics' cylindrical components have been widely used for laser based applications with reliable optical performance and durability. We are able to provide Zygo report of all cylindrical surfaces we produce, and intensive measurement can be met upon customer’s request, such as optical axis deviation.

We are working closely to innovators and photography equipment designers who develop customized anamorphic systems where use cylindrical lenses as image aspect ratio changer.

For attach-on anamorphic lenses for smart phones, anamorphic cinema projection system, and front mounted anamorphic attachment. Please check out our anamorphic lenses for more information. If you are in the stage of developing your own anamorphic lenses, don’t hesitate contacting one of our optical engineers for free consultation to receive assistant from manufacturing perspective.

At Hyperion optics, we keep utilizing optical edging technique for most demanding requirement, which is essential in cylindrical component manufacturing. We provide full inspection data along with shipment including Zygo interferometry report and centering testing results.

Achromatic cylindrical lenses are ideal for eliminating spherical and chromatic aberration at the image plane, for example using monochromatic light source, achromatic cylindrical lenses can form a 50-90% smaller spot compared to singlet.

For most severe laser or imaging applications which involve cylindrical components, such as anamorphic projection, anamorphic photography, and achromatic cylindrical lenses are introduced. Hyperion Optics can manufacture based on custom design doublet or triplet achromatic cylindrical cemented lenses by using centering alignment device with UV curing unit to process precision bonding and testing at the same time. Every singlet is fully inspected before bonding.

Hyperion Optics provides various fan angle line generating Fresnel lenses for laser alignment and machine vision applications. Unlike ordinary cylindrical lenses, line generating Fresnel lenses can produce uniform distribution of energy along the line.

We provide in both optical glass (N-BK7 or equivalent) and plastic version for your specific requirement. With our highly efficient cementing techniques, we support low volume customized solution and performance trial. Please note, free sampling is available upon request for all fan angle products.

Diameter varies from 4mm to 8mm, 2/2.5mm +/-0.1mm in center thickness. Fan angle available from 110°, 20°, 14°, 10°, or custom made. Our optical glass version line generating Fresnel lenses have much better imaging quality, which is also high working temperature durable. Compared to rod lenses, our products are much easier to mount.

Cylindrical lenses are used to focus, expand or condense light into a single dimension. Cylindrical lenses are widely used in laser scanners, optical information processing and computing, dye lasers or anamorphic lenses. Hyperion Optics has decade of cylindrical lenses manufacturing experience, ranging from ordinary plano-convex, plano-concave to cemented achromatic cylindrical lenses.

For most laser applications, Hyperion Optics’ cylindrical lenses offer always comes with competency in price; our monthly capability is 3,000 pcs. For prototyping quantity, we provide interferometry report along with the shipment upon request.

Rod lenses’ optical performance is similar to cylindrical lenses, incident collimated light passes through the polished circumference of the rod lens will be formed into a line. Variety of laser and imaging applications utilize rod lenses as line generator optics.

Hyperion Optics provides a range from micro sized rod lenses manufactured with variety of optical materials including fused silica ultra-violet version for OEM applications, also custom sizes and variations in surfaces requirement additional coatings are available upon request.

Engineers normally find that the optical uniformity varies from center to the two ends on a rod lens, Hyperion Optics insists polishing circumference on a longer length rod substrates then slice and ground the ends to tolerance to yield a better polishing result which would impact on the overall line uniformity in actual use.

Infrared Lenses

We work on a wide range of infrared materials that covers almost full infrared spectrum. Hyperion Optics supplies Zinc Selenide, Zinc Sulfide, Silicon, Germanium, Gallium Arsenide, and Calcium Fluoride, Barium Fluoride as well as Chalcogenide spherical lenses and aspherical lenses. We use laser based edging device to control MWIR and LWIR lenses’ decenter deviation, and test on reflective centering station to fulfill extreme precise tasks.

Zinc Selenide has great transmittance through the band 0.5-22μm, especially at 10.6μm, and is commonly used in thermal imaging and FLIR systems, also its outstanding low absorption coefficient and high resistance to thermal shock makes it an ideal choice for high power CO2 laser applications. For laser ZnSe components please browse our Laser Optics category for more information.

Since Zinc Selenide is a relatively soft material that scratches and digs can be easily remained on the surfaces during processing flow, it is not recommended for use within harsh environments, Hyperion Optics’ advanced manufacturing techniques for ZnSe ensure superior surface quality compared to our competitors. For cosmetic sensitive systems, our best effort can reach 20-10 in S/D grade. ZnSe aspheric lenses are also available for your application; please refer to IR Aspheric Lenses for more information. ZnSe Dome optics are also available in our Dome category.

Our infrared lenses are also available with AR coating according to specific requirement. Please take great care when handling, mounting and cleaning infrared lenses, further, For your safety, please follow all proper precautions, including wearing gloves when handling these lenses and thoroughly washing your hands afterward.

In addition, along with our outstanding aspherical (including DOE surface) manufacturing capability, Hyperion Optics is definitely one of your best choices in SWIR/MWIR/LWIR lenses development project.

Types of infrared lenses:

Chalcogenide Lenses

Barium Fluoride Lenses

Calcium Fluoride Lenses

Magnesium Fluoride Lenses

Gallium Arsenide Lenses

Germanium Lenses

Sapphire Lenses

Silicon Lenses

Zinc Selenide Lenses

Zinc Sulfide Lenses

Take two as examples:

Chalcogenide Lenses

Chalcogenide glass is containing one or more chalcogens (sulfur, selenium and tellurium, but excluding oxygen). Chalcogenide components are becoming popular in various IR applications due to its excellent wide band transmittance (3-5µm, 8-12µm) with reliable machinability, which perform rather differently from oxides; particularly low band gaps help optical designers to introduce more flexible IR solutions.

Zinc Sulfide Lenses

Based on Hyperion Optics' IR material processing capability, we now introduce our Chalcogenide glass family components, as equipped with the most advanced manufacturing devices, Hyperion Optics is able to deliver quality Chalcogenide components just like other IR materials. Our Chalcogenide material inventory ranges from Schott IRG22, IRG23, IRG24, IRG25, IRG26; in addition, as our partnership with China based material vendor HUBEI NEW HUAGUANG (Known as NHG) Material Technology Co., Ltd,. We also supply Chalcogenide components with their Chinese equivalents which is a highly cost-effective solution for our potential customer whether it is a concept approval project or series production scenario.

With the rapid development of military weaponry and correlative targeting and monitoring systems, ZnS is widely utilized in multi-spectral IR applications. Its relatively high transmittance through 3-5µm and 8-10µm enable ZnS being an ideal choice for multi-spectral applications. Further, within NIR and SWIR range, CLEARTRAN CVD ZnS can also be considered as indispensable alternative for optical designers.

What is optical mirror

Optical Mirrors are designed to reflect light for a variety of applications, including beam steering, interferometry, imaging, or illumination. Optical Mirrors are used in a wide range of industries, such as life sciences, astronomy, metrology, semiconductor, or solar.

Hyperion Optics offers a range of laser, flat, metal substrate, focusing, or specialty Optical Mirrors in a multitude of reflective coating options, including Protected Aluminum, Enhanced Aluminum, Protected Silver, Protected Gold, or Dielectric. Choosing the proper reflective coating option ensures high reflectivity of the needed wavelength or wavelength range. Optical Mirrors designed for laser applications are optimized for the given laser wavelength. Additionally, Optical Mirrors designed for lasers feature damage thresholds that are suitable for the designated laser. Metal substrate Optical Mirrors are ideal for applications requiring a constant coefficient of thermal expansion between the Optical Mirror and the mount. Optical Mirrors with a concave surface are ideal for light focusing applications.

Optical mirrors have a smooth, highly-polished, plane or curved surface for reflecting light. Usually, the reflecting surface is a thin coating of silver, or aluminum on glass. Product specifications for optical mirrors include diameter, radius of curvature, thickness focal length, and surface quality. The diameter or height of an optical mirror is measured straight on. If the optical mirror’s curvature was extrapolated into a sphere, then the radius of that sphere is the radius of curvature for the mirror. There are two thickness measurements for optical mirrors: center thickness and edge thickness. Units of measure include inches, feet, and yards; nanometers, centimeters, and millimeters, and miles and kilometers. With optical mirrors, focal length is the distance from the mirror at which light converges. Surface quality describes digs and scratches. A dig is a defect on a polished optical surface that is nearly equal in terms of length and width. A scratch is a defect whose length is many times its width.

Optical mirrors are made from many different materials, each of which influences the mirror’s reflectivity characteristics. Choices for materials include borosilicate glass, copper, fused silica, nickel, and optic crown glass. Borosilicate glass is also known as BK7 and boro-crown glass. Copper is used in high-power applications because of its high thermal conductivity. Fused silica has a very low coefficient of thermal expansion and is suitable for use with moderately-powered lasers or changing environmental conditions. Ultraviolet (UV) grade optical mirrors are also commonly available. Nickel is used in applications which require resistance to both thermal and physical damage. Proprietary materials for optical mirrors include Pyrex (Corning Inc.) and Zerodur (Schott Glaswerke).

Optical mirrors are sometimes coated to enhance their reflectivity. Choices include bare, enhanced, and protected aluminum; silver, bare gold and protected gold; and coatings made from rhodium and dielectric materials. Enhanced aluminum coatings are used to improve reflectance in the visible and ultraviolet regions. Protected aluminum coatings provide abrasion resistance while protecting the surface of the aluminum, an excellent reflector in the upper UV, visible and near-infrared (IR) regions. Optical mirrors with bare gold and protected gold coatings are used in the near-IR to far-IR regions. Silver coatings provide better reflectance than aluminum; however, silver’s tendency to oxidize and tarnish requires thorough sealing from the atmosphere. Rhodium coatings have a reflectivity of approximately 80% of the visible spectrum.

Heat mirrors and cold mirrors are special bandpass filters that can reflect infrared light and ultraviolet light and only allow visible light to pass through, also known as heat-absorbing filters, also known as IR cut filters. Heat Mirror will be a large number of heat generated near-infrared light isolated optical path to protect the heat-sensitive devices, where the need for high light intensity and need to be separated from the heat applications can be.

Reflective film from the coating material can generally be divided into two categories; one is the reflective metal film, one is all dielectric reflective film.

Media reflection film using the principle of multi-beam interference, which, contrary to the media anti-reflective film, can significantly improve the light in the air glass interface reflectivity. By alternately plating high and low refractive index multilayer films on the surface of the lens, the synthetic amplitude of the reflected light can be increased, and the reflectivity of the reflective film can be more than 99.9% of specially optimized design. In contrast, the reflectivity of the reflective metal film is only 97%.

What is optical filters

Fluorescence filter is a fluorescence imaging filter for biomedical and life science instruments, the key components, the main role is in the biomedical fluorescence analysis system for the separation and selection of substances in the excitation and emission fluorescence Of the spectral characteristics of the band. It is usually required that the filter cut-off depth be greater than OD5 (optical density, OD = -lgT). The core requirements for filters used in fluorescence detection systems are high cut-off steepness, high transmittance, high positioning accuracy, high cut-off depth, and excellent environmental stability.

Fluorescence filter is a combination of three, three are excitation filters, emission filters and dichroic filters.

Excitation Filter (Exciter Filter, Excitation Filter, Excitation Filter): In the fluorescence microscope, only the excitation wavelength of the filter can pass through the fluorescence. In the past, a short-pass filter was used, and now a band-pass filter is basically used. The housing is marked with arrows indicating the direction of propagation of the recommended light.

Emission Filter (Emitter Filter, Emitter): Select and transmit the fluorescence emitted by the sample, the other range of light cut-off. The wavelength of the emitted light is longer than the wavelength of the excitation light (closer to red). A band-pass filter or a long-wave-pass filter may be selected as the emission filter. The housing is marked with arrows indicating the direction of propagation of the recommended light.

Dichroic Mirror (Dichromic Beamsplitter, Dichromatic Beamsplitter): also known as dichroic mirrors or dichroic mirrors. And placed at an angle of 45 ° to the optical path of the microscope. This filter reflects one color of light (excitation light) and transmits another color of light (emitted light), the reflectivity of the excitation light is greater than 90% and the transmittance of the emitted light is greater than 90%. The impervious portion of the spectrum is reflected rather than absorbed. Filter in the transmitted light and reflected light color complement each other, and thus also known as dichroic filters.

Our optical filters are designed for fluorescence imaging applications, with durability in mind and high-performance optical specifications in manufacturing. The filter substrate is made of quartz, which can achieve 1/10 lambda surface accuracy, while the thermal expansion coefficient of quartz is relatively small, can obtain higher image quality.

We equipped with 4 coating chambers to provide various filters to our customers. For custom specifications, please talk to our coating engineers, we are more than happy to simulate the coating result for you. Contact us today, and find out our coating capability for your needs.

Band pass filter can separate a band of monochromatic light, the ideal transmittance of band-pass filter through the bandwidth is 100%, while the actual band-pass filter pass band is not the ideal square. The actual band-pass filter generally has a center wavelength λ0, a transmittance T0, a half width of the pass band (FWHM, a distance between two positions where the transmittance in the pass band is half the peak transmittance), the cutoff range and other key parameters to describe.

Multichannel filters differ from conventional bandpass filters by allowing only one continuous band of light to pass through it, allowing two or more bands of light to pass through.

Multi-channel filters can be achieved on a filter to achieve the need for multiple general filter stack to achieve the effect, making the design more compact, and can reduce costs.

This filter in the optical communications, infrared and medical applications have a wide range.

Neutral gray-scale filter is a non-selective filter, that is, ND mirror for a variety of different wavelengths of light to reduce the capacity is the same, uniform, only to weaken the role of light, and The original color of the object will not have any impact, so you can reproduce the real scene contrast.

The main purpose of using ND mirrors is to prevent over-exposure.

For example, when you want to extend the exposure time when the light is strong, use the ND lens to reduce the light entering the lens, you can use a slower shutter shot. For example, in the daytime when the light is strong with slow shutter speed to capture the waterfall to show the virtual effects of water and other special effects, you need ND mirror.

What is Prisms optical

Hyperion Optics supplies a range of prisms optical to meet UV-Visible-NIR applications, with high surface quality and tight tolerance angles.  Our materials selection ranges from flint/crown glasses, fused silica, ZnSe, CaF2 etc.

For custom need, such as cemented prism or additional treatment on the surfaces, please have us assess your requirement, our engineers are always happy to assist.

Right angle prisms turn light through 90° by internal reflection from the hypotenuse, or 180° from two right angle surfaces. When the light incident angle is perpendicular to the right angle surfaces, the light will be reflected at the surface of glass/air interface.

When the input light is incident from hypotenuse surface, the light will be fully reflected in the glass / air interface at the right angle surfaces. The second total reflection occurs at next right angle surface.

Compared to regular reflective mirrors, right angle prisms are easily to be mounted; further its reliable mechanical stress has better stability and strength. Hence right angle prisms have been considered as suitable alternatives to reflective mirrors in various applications.

Hyperion Optics supplies a range of right angle prisms to meet UV-Visible-NIR applications, with high surface quality and tight tolerance angles.  Our materials selection ranges from BK7, Bak4, fused silica, ZnSe, CaF2 etc.

Material tips for your application:

• For working wavelength down to 175nm or so, with low thermal expansion requirement, Fused silica is the right choice with tighter tolerance control due to its excellent mechanical stability.
  
• For visible and NIR wavelength, N-BK7 or CDGM H-K9L is suitable and cost effective.
  
• For infrared wavelength, ZnSe and germanium are the right material to pick up.
  
• Calcium fluoride has relatively wide transmittance range from 0.18~8um, it is the best choice when your application covers such wide transmission range.

Hyperion Optics has full capability of processing right angle prisms based on the materials we proposed above with 3 precision levels fit your actual demand.

Cemented Prism Cube

Hyperion Optics are specialist of providing custom prisms, meanwhile, we are also capable of precision prism bonding of custom design.

From simple bi-prism bonding to multiple elements cementing, we provide detailed testing report regarding key specs such as angles, surface accuracy and coating measurement. Let us help you with your own custom bonding design.

Corner cube is total reflecting prism formed by 3 perpendicular surfaces, where the incident light angle does not influence the final emerging light angle but reflected by 180°, it offers excellent parallelism between the incident and exit beams.

Hyperion Optics supplies both corner cube in mount or without mount, our precision corner cube retroreflectors have been used for Laser ranging, positioning and guidance, laser communication, optical transformation.

Dove prisms are used as reflective prism inverting the image. Dove prism is shaped from a truncated right-angle prism. Normally, dove prisms are used in the parallel optical path based on critical angle principle to meet total internal reflection with limited FOV.

A beam of light entering one of the sloped faces of the prism undergoes total internal reflection from the inside of the longest (bottom) face and emerges from the opposite sloped face. Images passing through the prism are flipped, and because only one reflection takes place, the image is inverted but not laterally transposed.

Optical Window

Hyperion Optics supply a range of custom precision grade windows, elliptical windows to seal optical enclosures especially suited to small power laser applications. Windows can be provided uncoated, or AR coated on single or both faces, or to your custom wavelength requirement. Our custom windows can also be coated with beamsplitter and mirror coatings to meet your bespoke customer needs.

Our precision optical windows range from UV to VIS, NIR, SWIR further MWIR and LWIR applications. We offer a variety of substrates, such as Germanium (Ge), Silicon (Si), N-BK7, UV Fused Silica, Zinc Selenide (ZnSe), or Multiple anti-reflection coating options are available for the Ultraviolet (UV), Visible, or Infrared (IR). Please also refer to our IR optics category for more information.

We are confident to provide our valued customer the best cost-effective offer which can improve your instrumentation and supply chain experience.

Borosilicate Windows

Borosilicate Windows are ideal for high temperature and harsh environment applications. With its excellent shock and thermal resistance property, borosilicate window products can maintain flatness in different environmental conditions.

Unlike common borosilicate that is drawn flat, is produced by a float technique that yields superior surface flatness — typically 4 - 6λ per inch.  For more information per material property, please refer to Schott official  brochure.

Hyperion Optics orders directly from Schott, offer two grades of custom borosilicate or equivalent windows, float grade which are cut from standard float sheet material and polished grade which are further intensively polished for better flatness and surface quality according to application requirement. We have been providing our standard and custom optical window for filter, first surface mirrors, protection windows utility.

Infrared Windows

Among other materials for Hyperion Optics showing good transmission in 2-15 µm range. Due to high refractive index Ge lenses became very useful components of IR imaging systems operating in both “atmosphere windows”: 3-5 and 8-12 microns.

Both monocrystalline and polycrystalline Ge may be used for manufacturing of optical components. We produce Germanium lenses and windows for infrared thermal imaging applications and pyrometry (see our webpageGermanium windows and lenses for thermography). Also such components for spectroscopy as ATR prisms,detector windows, and IR Polarizers are available.

Ge is also good electromagnetic interference (EMI) shielding material. Its special grade called EMI for its ability to shield against electromagnetic interference has become increasingly important for modern military applications where other signals (within millimeter and centimeter range) can be strong enough to make nearby IR systems ineffective. Typical resistance for EMI grade Germanium is about 4 Ohm x cm but it depends on required level of spurious signal suppression. Using Ge window with such resistance these signals are effectively shorted out and the IR system shows good performance.

ZnSe ZnS window

• Low Dispersion
• Available Uncoated or AR Coated
• Ideal for Thermal Imaging, FLIR, and Medical Systems

Hyperion Optics Zinc Selenide Windows (ZnS Windows) are perfect for a wide variety of infrared applications including thermal imaging, FLIR, and medical systems. This chemical vapor deposited material has extensive usage in high power CO2 laser systems because of its low absorption coefficient and high resistance to thermal shock. Zinc Selenide (ZnSe) is a relatively soft material that scratches easily, and it is not recommended in harsh environments because its Knoop Hardness is only 120. When handling, apply uniform pressure and wear Latex finger cots or gloves to prevent contamination.

Light Guides

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Hyperion Optics’s ranges of custom light guides are available in a variety of materials. Currently, we offer BK7 or equivalent, Sapphire or equal and UV Fused Silica light guides, in an assortment of diameters and thicknesses.It serves as the key element in cosmetic laser or intense pulsed light (IPL) applications. IPL is commonly used for the removal of unwanted hair, as well as a range of other cosmetic applications. IPL applications make use of a variety of wavebands to target different chromophores. For this reason, our custom light guides are available in a choice of materials to suit your waveband requirement.

Our custom BK7 or equivalent light guides offer a high internal reflection to minimize the loss of transmitted light. BK7 or equivalent can provide over 90% transmission between 330 and 2000nm, which makes this material an excellent choice for IPL applications used to treat pigmentation, as the peak absorption of the human pigment melanin is 335nm. BK7 or equivalent is also recommended for its high homogeneity and low bubble and inclusion content.

Our product also provides over 90% transmission at 335nm and work efficiently down to 185nm, making them an excellent alternative to BK7 or equivalent for pigmentation treatment. Besides, our custom fused silica light guides offer high thermal conductivity and an increased laser damage threshold, both of which are essential for cosmetic laser applications.

We also provide custom sapphire lenses light guides, a common alternative to BK7 and fused silica. Sapphire is a highly hard material, which offers increased durability and resistance to damage. Sapphire also provides excellent transmission over the entire visible and SWIR range.

A light-guide manipulates, or guides, the light to illuminate a larger lighting surface area.Lightguides, like light pipes, will also be made from optically transparent polymers, such as polycarbonate or acrylic.It made to your exact specification, available in UV fused silica, BK7 or equivalent and sapphire or equivalent for use in a variety of wavebands. Our highly skilled metrology and QA technicians can individually inspect and test each component to ensure it meets our excellent quality standard.

Quartz Fused Silica Windows

Hyperion Optics supplies a wide range of custom Quartz, UV fused silica and IR fused quartz windows through UV to infrared spectrum.

Custom quartz windows: have a useful transmission range from 0.26 visible to 2um in the infrared, which working temperature up to 1050°C, with typical AR coating applied, quartz windows are suitable for most visible to infrared applications.

Germanium Window

In the range of 2-12 μm, germanium is the most commonly used material for the production of spherical lenses and windows for high efficiency infrared in imaging system. Germanium has a high refractive index (about 4.0 through 2-14μm band), usually do not need to be modified due to its low chromatic aberration in low power imaging systems.