COLORED FILTER GLASS
We have a large portfolio of colored filter glass compositions that are engineered to transmit or absorb light in the ultraviolet (UV), visible, and infrared (IR) regions of the electromagnetic spectrum. New technologies and applications are constantly evolving and frequently require custom filter glass compositions. We operate in a single, integrated manufacturing facility with in-house research and engineering capabilities. This enables us to quickly develop custom glass compositions and to manufacture filter glass that meets the demands of emerging technologies.
SIZE AND FORMAT
Molded: Go Beyond the Square
Filter glass doesn’t always have to be square; it can also be molded into complex, contoured shapes. Our unique manufacturing process enables us to mold filter glasses into shapes that are traditionally difficult — and expensive — to achieve through machining and fabrication. We can even manufacture flat molded shapes in various sizes; this helps to reduce fabrication costs and reduces the overall cost of your parts.
If you could design a better performing part or system with the use of optics, contours, or other features, you should be able to. Don’t be constrained by the traditional square format; gain greater flexibility and design freedom by considering molded filter glass.
Our filter glasses are available as unfinished, 6" - 6.5" (15.2 cm - 16.5 cm) square blanks and are supplied at a nominal thickness of +2mm/-0mm. This standard format enables efficient processing and easy inspection.
GLASS TYPES AND APPLICATIONS
Visible Bandpass Filters
Visible bandpass filters are useful for isolating specific regions of a spectrum. They transmit light within defined wavelength ranges while absorbing other undesired wavelengths. We offer bandpass filters with high transmission in the blue-green, blue, and violet spectral regions.
- Blue-Green Bandpass Filters
- Blue-green bandpass filters can be used to selectively transmit and absorb wavelengths in the blue and green spectrums. The glasses provide high transmission in the blue-green region and high absorption in the longer yellow, orange, red, and infrared wavelengths. These filters are commonly used in electronic applications, such as in aviation instrumentation panels.
- Blue Bandpass Filters
- Blue bandpass filters can be used to selectively transmit and absorb wavelengths in the blue spectrum. The filters provide high transmission in blue region while absorbing much of the spectrum in the green, yellow, and in some cases red region. These filters are used in a variety of applications such as photography, astronomy, photometers, and in electronic sorting machines.
- Amethyst Filters
- Amethyst bandpass filters transmit violet, blue, and red wavelengths and provide absorption in the green and yellow regions of visible light. They are used for diverse applications such as medical illumination and color correction.
Ultraviolet Bandpass Filters (Ultraviolet Transmitting - Visible Absorbing)
Our ultraviolet (UV) bandpass filters are engineered to exhibit high transmittance in the UV-A, UV-B, or UV-C regions. These filters appear nearly black as they absorb almost all visible radiation but actually provide high transmission in the UV wavelengths of light. They are suitable for a wide range of applications, such as non-destructive testing equipment, tanning and phototherapy devices, forensic detection and analysis equipment, and theatrical lighting. We have filters that are tailored to industry applications with many of our glasses targeting high transmission at 254 nm and 365 nm.
Longpass filters are characterized by their ability to transmit over a wide spectral range with transmission being “cut-off” below a specific wavelength. They exhibit high transmission over the longer wavelength region and have full absorption in the shorter wavelength region. We offer longpass filters that span the ultraviolet, visible, and infrared regions. Longpass filters are useful for sorting applications, food and beverage inspection, imaging systems, machine vision, and sensing applications.
- Ultraviolet / Visible Transmitting
- These clear glasses feature high transmission across the UV and visible spectrum with tailored transmission cut-offs ranging from 310 nm to 390 nm. These filters can be used for UV curing systems and photolithography mask aligners.
- Sharp-cut Yellow, Orange, Red
- Our sharp-cut borosilicate filter glasses exhibit low thermal expansion characteristics and offer excellent durability in many applications. These glasses can be tailored for specific “cut-off” wavelengths with high transmission at longer wavelengths and full absorption at shorter wavelengths.
- Infrared (IR) Transmitting - Visible Absorbing
- Commonly used with night vision imaging systems (NVIS), IR transmitting visible absorbing glass blocks all visible light and allows IR light to pass through the glass.
Infrared Absorbing - Visible Transmitting (Heat Absorbing Filters)
Heat absorbing filters can be used to absorb infrared radiation. They’re useful for medical and dental applications when unwanted heat can impact patient and staff comfort.
At times, IR light is also unwanted in security and military applications. Our IR absorbing filters can reduce the signature (red and infrared wavelengths) of all light sources, preventing detection by typical night vision goggles. Select compositions meet the requirements for secure lighting for military applications.
This filter glass is nearly opaque to all radiations between 200 nm and 5 µm when used at 1.5 - 4.1 mm thickness. This glass is useful for direct viewing of extremely high intensity light sources such as the sun and some arc lamps as well as in calibration processes requiring full absorption.
Neutral Density Filter Glass
Neutral density filters evenly absorb light across the visible spectrum. They’re used to reduce transmittance of light in industrial and imaging applications. Lasers or other high intensity light sources can also cause damage to sensitive sensors and they may need to be attenuated with a neutral density filter. An excess of light can also cause over-exposure in imaging applications.
Neutral density filters are also used to test the photometric accuracy of instruments such as spectrometers.
Rare-earth Doped Calibration Filters
These filter glasses are commonly used as a standard for wavelength calibration of spectrophotometers or absorption of specific wavelengths. The filters have absorption bands that cover a wide range of wavelengths from the UV region (< 250nm) to the near infrared region (> 1.5um).
Most glasses have the capability to fluoresce to some extent when irradiated with energy. Our uranium doped glass exhibits a consistent yellow-green fluorescence when exposed to UV light and is useful for fluorescence microscopy.
Color Correction Daylight Blue Filters
If a light source appears too warm or too cool, it can significantly alter the perception of colors and the environment. A color correction filter adjusts the effective color temperature of the light system and can produce light with a correlated color temperature of 5500, 6500, or 7500°K. We offer two standard glass compositions which are widely used, but we can also develop custom correction filters for specific light sources and applications.
CUSTOM FILTER GLASS DEVELOPMENT
Technological innovations are rapidly changing our world; filter glass compositions that met specifications before, may no longer be compatible. As new technologies develop and change, our research and engineering team can create custom glass compositions that meet new requirements for thermal expansion, chromaticity, transmission, absorption, durability, and chemical resistance. Submit your requirements for custom glass development on our request a quote form.