Infrared (IR) Filters — Technical Guides for Optical Engineers

Infrared (IR) filters are optical components that transmit one band of infrared light and reject the rest. They are made by depositing a multi-layer thin-film stack onto an optical glass, fused silica or crystal substrate, so their behaviour is set by the coating design as much as by the glass: hard-coated interference filters, IR-cut (hot mirror) filters, band-pass filters, long-pass and short-pass edges and neutral-density parts all come out of the same coating process. This page collects every Jingyu Optics guide on the subject — 29 articles covering specification, selection, cost, quality, comparison and troubleshooting — so that an engineer can find the relevant note without searching.

How an IR filter is specified

The parameters below come up in every one of the guides, and each of them changes what a coating house has to do. They are the fastest way to describe a part in an enquiry.

• Centre wavelength (CWL) and pass-band width (FWHM): the band the part must transmit, and how wide it is.
• Transmission in band and blocking outside it (cut-off range and optical density): most IR filters fail on rejection, not on transmission.
• Edge steepness: how quickly transmission falls from pass band to blocking band, which decides how many coating layers are needed.
• Substrate and thickness: optical glass, fused silica, quartz or crystal glass, and the thickness that the mount and the wavefront budget allow.
• Angle of incidence: a coated filter shifts to shorter wavelengths as the incidence angle grows, so the working geometry belongs in the specification.
• Environment: operating temperature range, cleaning regime, abrasion and humidity exposure decide whether a hard coat and an environmental test are required.
• Mechanical tolerances: outside dimensions, thickness tolerance, chamfer, edge quality and surface quality grade.

All 29 IR filter guides

Specification guides

• IR Filters for IPL and Beauty Devices: Specification Guide for Optical Engineers
  Specifying IR filters for IPL and beauty devices is largely a matter of deciding which three numbers actually govern the application and letting the rest
• IR Filters for Medical and Life-Science Instruments: Specification Guide for Optical Engineers
  Specifying IR filters for medical and life-science instruments is largely a matter of deciding which three numbers actually govern the application and
• IR Filters for Solar and Photovoltaic Manufacturing: Specification Guide for Optical Engineers
  Specifying IR filters for solar and photovoltaic manufacturing is largely a matter of deciding which three numbers actually govern the application and

Selecting a filter for an application

• Selecting IR Filters for Biometric and Fingerprint Recognition: Material, Coating and Tolerance Trade-offs
  IR Filters covers a wider range of options than most drawings imply, and the differences between them decide both performance and price. This article
• Selecting IR Filters for Optical Communication and Datacoms: Material, Coating and Tolerance Trade-offs
  IR Filters covers a wider range of options than most drawings imply, and the differences between them decide both performance and price. This article
• Selecting IR Filters for Stage Lighting and Entertainment: Material, Coating and Tolerance Trade-offs
  IR Filters covers a wider range of options than most drawings imply, and the differences between them decide both performance and price. This article
• IR Filters for Time-of-Flight Sensing: Material, Coating and Tolerance Trade-offs
  Time-of-flight cameras build a depth map by timing a 940 nm VCSEL pulse against the return, and they do it in sunlight that dwarfs the signal. The

What drives cost and lead time

• IR Filters for Aerospace and Defense Optics: What Actually Drives Cost and Lead Time
  Two quotations for the same IR filters part in aerospace and defense optics can differ by a factor of three, and the reason is rarely the material. This
• IR Filters for Drone and UAV Imaging Payloads: What Actually Drives Cost and Lead Time
  Two quotations for the same IR filters part in drone and UAV imaging payloads can differ by a factor of three, and the reason is rarely the material. This
• IR Filters for Projection and Display Systems: What Actually Drives Cost and Lead Time
  Two quotations for the same IR filters part in projection and display systems can differ by a factor of three, and the reason is rarely the material. This
• IR Filters for Thermal Imaging and Night Vision: What Actually Drives Cost and Lead Time
  Two quotations for the same IR filters part in thermal imaging and night vision can differ by a factor of three, and the reason is rarely the material.

Inspection, standards and traceability

• Qualifying IR Filters for Agricultural Sensing and Crop Monitoring: Inspection, Standards and Traceability
  A part that measures correctly in the lab and fails in service is almost always a qualification gap rather than a manufacturing defect. This article sets
• Qualifying IR Filters for Gas Sensing and Environmental Monitoring: Inspection, Standards and Traceability
  A part that measures correctly in the lab and fails in service is almost always a qualification gap rather than a manufacturing defect. This article sets
• Qualifying IR Filters for Robotics and Factory Automation: Inspection, Standards and Traceability
  A part that measures correctly in the lab and fails in service is almost always a qualification gap rather than a manufacturing defect. This article sets

Failure modes and practical fixes

• Troubleshooting IR Filters in Architectural and Appliance Glass: Failure Modes and Practical Fixes
  Failures in IR filters used in architectural and appliance glass tend to follow a small number of patterns, and each pattern has a signature. This article
• IR Filters for Optical Fiber Sensing: Failure Modes and Practical Fixes
  Fiber Bragg grating interrogators and distributed fiber sensors read strain, temperature or vibration from light that travels down a fiber and returns at
• Troubleshooting IR Filters in Scientific and Laboratory Instrumentation: Failure Modes and Practical Fixes
  Failures in IR filters used in scientific and laboratory instrumentation tend to follow a small number of patterns, and each pattern has a signature. This
• Troubleshooting IR Filters in Security and Surveillance Cameras: Failure Modes and Practical Fixes
  Failures in IR filters used in security and surveillance cameras tend to follow a small number of patterns, and each pattern has a signature. This article

IR filters vs the alternatives

• IR Filters vs the Alternatives for AR/VR and Smart Glasses: A Practical Comparison
  There is always more than one way to solve the optical problem in AR/VR and smart glasses, and the options are not equally good at everything. This
• IR Filters vs the Alternatives for Hyperspectral Imaging: A Practical Comparison
  There is always more than one way to build a hyperspectral imager, and the options are not equally good at everything. A filter wheel, a linear variable
• IR Filters vs the Alternatives for Industrial Laser Processing: A Practical Comparison
  There is always more than one way to solve the optical problem in industrial laser processing, and the options are not equally good at everything. This
• IR Filters vs the Alternatives for Semiconductor and Photolithography: A Practical Comparison
  There is always more than one way to solve the optical problem in semiconductor and photolithography, and the options are not equally good at everything.

Design trends and sourcing notes

• IR Filters for Aquaculture and Water Farming: Design Trends and Sourcing Notes
  A camera on a fish cage, a raceway or a pond edge works through turbid water, low sun angles, salt spray and a surface that grows whatever the season
• IR Filters in Automotive ADAS and LiDAR: Design Trends and Sourcing Notes
  Requirements in automotive ADAS and LiDAR have been shifting - thinner parts, wider bands, harsher environments - and those shifts change what IR filters
• IR Filters in Machine Vision and Industrial Inspection: Design Trends and Sourcing Notes
  Requirements in machine vision and industrial inspection have been shifting - thinner parts, wider bands, harsher environments - and those shifts change
• IR Filters in Smartphone Camera Modules: Design Trends and Sourcing Notes
  Requirements in smartphone camera modules have been shifting - thinner parts, wider bands, harsher environments - and those shifts change what IR filters
• IR Filters in Spectroscopy and Analytical Instruments: Design Trends and Sourcing Notes
  Spectrometers and analytical instruments use IR filters to define the spectral windows the detector sees, and the demands on those filters keep tightening

Standards, traceability and documentation

• IR Filters in Satellite and Earth Observation Instruments: Inspection, Standards and Traceability
  An earth observation instrument is a radiometer that happens to fly. Its most consequential optical parts are band filters, and their job is not to make
• IR Filters for Thermal Imaging and Fire Detection: Inspection, Standards and Traceability
  Thermal cameras and flame or fire detectors rely on long-wave infrared filters whose spectral and environmental traceability decides whether the detector

Manufacturing and supply

Jingyu Optics Co., Ltd. is an optical component manufacturer in Zhuji, Zhejiang, China. The company supplies optical glass and fused silica substrates, custom multi-layer thin-film coatings and precision cold-fabricated glass components to OEM/ODM customers. The catalogue covers 426 products across three groups: coatings (255), materials (135) and fabrication (36).

Over 3,000 m² own plant, Class 1000 cleanroom, nearly 20 coating chambers, laser cutting machines, ultrasonic cleaning lines and spectrometric inspection systems; one-stop chain of substrate cold processing → multi-layer coating → ultrasonic cleaning → 100% final inspection.

Ordering: Sample lead time: 1–2 days for coated stock optics, and about 3 days for custom-coated parts, subject to coating design complexity. In-stock products ship within 1–2 days. Custom fabrication orders take approximately 5–7 days. Our team starts processing right after receiving your order. We can provide quotations and arrange expedited production if you have a required lead time. MOQ depends on the product. We are flexible: small-batch and trial orders are welcome for new projects, and we scale up to mass production once the design is validated. T/T bank transfer and major international payment methods. Shipping terms include EXW, FOB, CIF; by sea, air or express courier as you prefer. An engineer (not a robot) replies within 24 hours with a quotation and lead time. Enquiries go to the contact form or xiao@gobofactory.com.

Markets served: Europe, North America, Russia & CIS, Australia and New Zealand, South America, the Middle East, and China (mainland, Hong Kong, Macau and Taiwan).

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