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Edge Filters

Edge filters can detect boundaries between image areas. These boundaries have distinctly different brightnesses and reveal other aspects of image texture.

We offer four types of edge filters:

  • Notch
  • Long Wave Pass
  • Short Wave Pass
  • Multi-Edge


Notch optical filters are ideal for numerous illumination and detection applications because they block a preselected wavelength region while transmitting all other wavelengths outside that region. These filters can also remove a single laser wavelength from an optical system. As a result, our notch filters deliver rich, saturated colors with exceptional stability in virtually any environment. In addition, they provide durable, shift-free performance and reliable support for high-output lamps.

Unlike absorption filters or polymer gels, notch filters are practically absorption-free. As a result, you’ll get superior transmission, striking colors, and lifetime performance with no fading or aging.

These filters also have steep edge transitions between longer and shorter wavelength transmission and reflection bands — significantly steeper than polymer gels or colored glass.

Notch filters have many practical applications, including:

  • Entertainment, architectural and technical lighting.
  • Original equipment manufacturer (OEM) sensing and imaging.
  • Copy and print processing.
  • Machine vision.
  • Digital projection and cinema.

You can match or combine your notch filter with other filter types to optimize its performance in your specific application. Complementary filter options include:

  • Patterned color filters: provide smooth mixing from zero to full-color saturation. You can also use them to mix wide and rich color gamuts.
  • Color gobos: Full-color and multicolor gobos are micro-patterned for high-resolution, photorealistic images and effects.
  • UV-IR filters transmit visible color and block damaging ultraviolet (UV) and infrared light.
  • Cold mirrors: transmit infrared heat and light outside the device and reflect visible light into the illumination path.
  • Color correction filters: match the correlated color temperature of one lamp to another.

We provide custom notch filters designed to your custom specifications.

We are experts in developing solutions for your specific needs. We create filters tailored to your particular illumination source and optics to achieve your desired color output while matching your cut-on and cut-off wavelengths and calibrated colors.

We can pattern your notch color filters on gradient wheels or flags for superior RGB and CMY color mixing. Additionally, we can micro-pattern multiple colors using gobos and other photorealistic imaging effects. We can accommodate those requirements if you need a specific size, shape, or substrate to ensure the optics fit your application.

Order a notch filter from our inventory today for a quick-turn prototyping option. If you need additional customizations or placing a large-volume order, contact our sales team for assistance. Our friendly experts will be happy to answer all your questions and help you find the best filter options for your application.

Long Wave Pass

Our long wave pass (LWP) filters separate the light spectrum into reflected and transmitted components. Also known as an edge filter, LWP filters contain either a cut-on or cut-off slope that defines the transition between a highly reflective and a highly transmitted region. In addition, we use a technologically advanced sputtering method to apply multi-layer coatings to our filters, providing superior durability and stability in the highest-output light settings.

Contrary to the designs of conventional colored glass filters or polymer gels, our long wave pass filters are absorption-free, using thin-film interference technology to emit the richest possible colors. These filters also contain an increased edge steepness between wavelength bands to allow for accurate wavelength measurement.

Some popular applications of long wave pass filters include:

  • Microscopy
  • Fluorescence instrumentation
  • Raman spectroscopy
  • Light engines and broadband illumination
  • Original equipment manufacturer (OEM) optical systems

We stock a wide variety of LWP filters for performance in visible (VIS), ultraviolet (UV), infrared (IR), and near-infrared (NIR) wavelengths. We can customize our LWP filters to match your application’s specific wavelength and angle requirements to deliver the targeted blocking you need. In addition to our innovative coatings, we can customize our LWP filters by cutting them into various shapes and sizes.

Benefits of long wave pass filters:

  • High-transmission properties produce peak visibility
  • Rejection of unwanted wavelengths prevents damage
  • Maintain color integrity without shifting
  • Provide superior stability in high-humidity and elevated temperatures
  • Fully customizable

Our stock LWP filters are the perfect alternative to costly sample fabrication when you need a quick, economical prototype.

Custom Long Wave Pass Filter Options

Our engineering team has decades of experience using optical solutions and thin-film technology to develop custom filters specific to your application. Our designers will focus on your requirements by considering operating temperatures, humidity ranges, equipment limitations, manufacturing tolerances, and other critical factors. Our top priority is maximizing the performance and improving the efficiency of your operation.

Our customization processes involve applying multiple coatings to the same filter to enhance the size and weight. For more complex applications, filter designs can combine to produce the desired effect. For example, long pass and short pass filters can stack to create a custom bandpass filter.

Other filters that can pair with LWP filters include:

  • IR filters: These filters block IR radiation to reduce heat while transmitting visible light.
  • Cold mirrors: Cold mirrors reflect visible light while transferring heat outside or to the rear of the filter.
  • Color correction filters: These filters adjust the temperature of a specific color to produce the desired effect.

Connect with Salvo Technologies for Your Long Wave Pass Filter Needs

Whether you need a stock LWP filter, a custom design specific to your operation, or a quotation on a high-volume run, the staff at Optical Filter Shop is ready to serve you. Contact us today to learn how we can help your operation succeed.

Short Wave Pass

Short wave pass filters transmit shorter wavelengths and reflect more prolonged emissions making it easy to separate excitation from emitted wavelengths without interfering with your targeted wavelengths. Moreover, they have a high transition rate between reflection and transmission regions, making them an excellent choice for fluorescence, color enhancement, and photometry applications.

You can utilize short wave pass filters in applications such as:

  • Copy and print processing.
  • Original equipment manufacturer (OEM) sensing and imaging.
  • Digital projection and cinema.
  • Machine vision.
  • Architectural, technical, and entertainment lighting.

Integration Opportunities for Short Wave Pass Filters

While you can use short wave pass filters independently, you can also use them with other filters to enhance your results. For example, you might try matching or combining your short wave pass filter with:

  • Color gobos: Choose from full-color or multicolor gobos micro-patterned for high-resolution, photorealistic effects and images.
  • Patterned color filters: These filters provide precise mixing to achieve your desired color saturation.
  • Cold mirrors: Cold mirrors reflect visible light while transmitting infrared light and heat.
  • Color correction filters: These filters modify a lamp’s correlated color temperature to match another.
  • UV-IR filters: These filters reflect infrared and ultraviolet (UV) light while transmitting visible colors.

Short Pass Filter Customization Options

We customize your short wave pass filters to meet your unique needs. We match calibrated colors and specific cut-off wavelengths, engineering your optics to deliver your specified color output. We can also design the filter to your precise shape, size, and substrate requirements.

Multi-Edge Filters

We produce high-performance, multi-edge filters ideal for fluorescence microscopy, high-speed imaging, and numerous other applications. These filters have high transmission and reflection regions separated by a steep edge.

We offer two types of multi-edge filters: UV-IR Filters & Dichroic Color Filters. Additionally, we can customize our multi-edge filters to your needs to ensure the best performance.

Multi-Edge Filter Applications

Utilize our multi-edge optical filters for a range of applications, including:

  • High-intensity lamps.
  • Lighting reflectors.
  • Projection displays.
  • Original equipment manufacturer (OEM) optical systems.
  • OEM sensing and imaging.
  • Broadband illumination and light engines.
  • Technical, architectural, and entertainment lighting.
  • Copy and print processing.
  • Machine vision.

Our UV-IR filters block ultraviolet (UV) light and infrared radiation (IR) from high-intensity arc lamps in projection display systems. As a result, they suppress light that can damage polymer optics, microdisplay panels, and other optical components. They also reduce the heat load on these components throughout the optical train.

These filters benefit from a proprietary sputter deposition technology, which creates a dense coating with exceptional optical stability in varying environmental conditions and high operating temperatures.

Other features and benefits of our multi-edge, UV-IR filters include:

  • Excellent color integrity with no color shift.
  • Narrow cut-on/cut-off edge tolerances.
  • High visible transmission.

Our dichroic color filters provide consistent, vibrant colors for many detections and illumination applications. Also known as interference or thin-film filters, these color filters have a multilayered sputtered coating for durable, shift-free performance. They also resist aging and fading in high-output luminaries.

Additional features and benefits of these multi-edge color filters include:

  • Rich saturated colors.
  • High transmission with low absorption.
  • Spectral stability indoors and outdoors.
  • Standard and custom color availability.

Multi-edge UV-IR and color filters are often combined or matched with each other or different filter types to provide the best performance for your application. Some complementary filter types include:

  • Cold mirrors transmit infrared light and heat while reflecting visible light into the illumination path.
  • Color correction filters alter the correlated color temperature of one lamp to match another.

Custom Multi-Edge Optical Filters

We produce custom UV-IR and color multi-edge filters. We engineer our filter solutions to your specific optics and illumination source to deliver your targeted color output. We also match specific wavelength, angle, size, substrate, and shape requirements.

We can pattern on flags or gradient wheels for color filters to provide smooth CMY or RGB color mixing. We can also micro-pattern multiple colors to create full-color and photorealistic imaging effects and gobos.