Optical Filter Fabrication

There are perhaps about as many types of glass filters as there are applications for them. Yet despite all the variety, one thing is clear: Sydor Optics offers exceptional manufacturing capabilities when it comes to custom optical filters. With the largest collection of double-sided grinding and polishing machines in North America, Sydor Optics can precisely fabricate custom filters to meet your exact requirements, from basic prototyping to high-volume production and every step in between. While color glass filters can be ordered directly from the original manufacturer, standard surface flatness and transmitted wavefront tolerances may not meet your precision requirements which is why Sydor Optics double-sided polishing process stands out.

Sydor Optics has extensive experience manufacturing uncoated filter substrates and colored filter glass. Common optical filters include shortpass, longpass, bandpass, notch and edge with filter coatings suited for the infrared (IR), ultraviolet (UV) and visible (VIS) color spectrums.

Optical filter fabrication

Our capabilities include:

  • styled list bullet High-Volume Capabilities
  • styled list bullet Custom manufacturing of uncoated filters
  • styled list bullet Available in a variety of materials and sizes

Available Optical Substrate Types

Based upon customer demand, Sydor Optics offers Optical Filters made from the following substrate materials. Of course, if you don’t see a material you need, please contact a Sales Engineer, who will gladly discuss additional options that may be available.

Optical Filter Manufacturing Limits

Diameter / Thickness / Length / Widthmaterial dependent
Diameter Tolerance± 0.1mm
Thickness Tolerance± 0.01mm
Cosmetics (MIL-PRF-13830B)60-40 to 20-10
Surface Roughness – before coating≤ 10 Ǻ rms
Parallelism≥ 1 arc second
Transmitted Wavefront Error (TWE)* – before coating> 1/20 wave over clear aperture
Optical Density Tolerance (uncoated)± 0.01 OD
Optical Density Tolerance (coated)± 0.03 OD
Clear Aperture≤ 95%
Optical filters

Types of Optical Filters

Color Filters

Color glass filters are fabricated to selectively transmit a particular range of wavelengths or colors of light. In designing color filters to transmit a particular range, they’re also designed to block other wavelengths or colors. Sydor Optics can fabricate custom color filters to allow long wavelengths to pass (longpass), or short wavelengths (shortpass), or both (bandpass).

Dichroic Filters

Sydor Optics fabricates dichroic filters to transmit a particular range of the spectrum (the passband) while reflecting another range (known as the rejection band). Dichroic filters are commonly used for color separation in digital projection and CCD imaging. Sydor Optics can handle the custom fabrication of even the most complex dichroic filters.

Bandpass Filters

Bandpass filters are basically designed to selectively transmit a particular spectrum range and reject the other wavelengths. Bandpass filters are commonly used in a variety of applications, including chemistry, fluorescence microscopy, high-speed optical imaging, and spectroscopy.

Longpass Filters

As their name implies, longpass filters are designed to allow only long wavelengths to pass while blocking shorter wavelengths of light.

Shortpass Filters

Shortpass filters are a type of edge filter, designed to isolate desired wavelengths in the spectrum, and “cut” undesired wavelengths out of the optical system.

Notch Filters

Notch filters can be fabricated to the most demanding specifications for use in laser-based fluorescence, multi-photon microscopy, and Raman spectroscopy, and other high-speed imaging applications. As with other types of optical filters, Sydor Optics can fabricate custom notch filters to meet your specific needs and applications.

Edge Filters

As with other kinds of optical filters, edge filters are designed to separate a broad spectrum of light into light that is transmitted, and light that is rejected, or blocked. Edge filters can be used to reduce harmonics and light scatter and can be fabricated to function as longpass, shortpass, or bandpass filters.

Neutral Density (ND) Filters

Neutral density filters can be used to reduce the intensity of light by reflecting or absorbing a percentage of light at a specific wavelength. Neutral density (ND) filters reduce light intensity by absorbing or reflecting light and provide even attenuation across the specified wavelengths.

Infrared (IR) Filters

Infrared filters allow for high transmission in the IR spectrum and strong rejection to isolate even the narrowest band of wavelengths. As their name implies, IR filters can be fabricated for use in the harshest environments in FLIR, security, environmental and other infrared applications.

Ultraviolet (UV) Filters

Ultraviolet (UV) filters are used to block ultraviolet light (UV blocking), but allow visible light to pass. Sydor Optics can fabricate custom UV filters to meet your specific needs and applications including combining UV filters with other (bandpass/longpass) optical filters.

Broadband Filters

While certain kinds of optical filters are used to narrow wavelength ranges, broadband filters are designed to do the opposite: provide exceptional transmission throughout a broad range of wavelengths (but still exclude or reject the rest). Sydor Optics can fabricate custom broadband filters in various shapes and sizes to meet your specific needs and applications.

Filter Substrates

Sydor Optics can also manufacture filter substrates for you to coat. Our double-sided grinding and polishing machines allow for filter substrates created precisely to your specifications and are ideal for third-party coating.

Available materials for filter substrates include fused silica, display glass, low expansion, and optical glass. Please contact a Sales Engineer who will be happy to discuss all options for filter substrates.

Filter Shapes

Sydor Optics can manufacture custom optical filters — with various shapes and sizes — using CNC Glass Machining capabilities to meet your specific needs.

Some of the standard optical filter shapes that Sydor Optics customers frequently order include:

  • Circular Filters
  • Square Filters
  • Rectangular Filters
  • Elliptical Filters

Optical Filter Applications

  • Cinematography
  • Clinical Chemistry
  • Laser Systems
  • Machine Vision
  • Microscopy
  • Signal Attenuation
  • Spectroscopy
Optical filter fabrication

If you are starting a new program or need assistance, please contact us.

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