Custom Optical Filters are filters that allow the passage of one or more stated wavelength while blocking the remains. They are also defined as reflexive devices that permit the transmission of a detailed wavelength of light usually employed in an optical path that may have interfering coatings. Bandpass filters are often referred to as wavelength range (also identified as passband) such that they are intended to transmit.

What are the types of Custom Optical Filters?

The most recognized types of optical bandpass filters are of two types which include Absorptive and Dichroic filters. 

  • Absorptive filters: They are those filters which have the covering of organic or inorganic materials such that they transmit certain wavelength of light while absorbing what’s left. They operate by reduction of light through absorption of indicated wavelength. Absorptive filters are made from colored glass, plastic-coated glass etc. They are cost-effective, have good blocking and effective transmission. They are applied in infrared or ultraviolet blocking, projectors, fluorescence microscopy, and stage lighting etc.
  • Dichroic filters: They may either be termed reflexive, thin or interference filters which reflect the undesired portion of the light and transmit the leftover. They are made by coating a substrate glass with a series of optical coatings. They operate using the principle of interference resonating with the desired wavelength of light and destructively reflect others as troughs of waves overlap. They are used in color correction, lighting systems, photography etc. The types of these filters include long pass, short pass, bandpass, additive, and subtractive filters.

Applications of Custom Optical Filters

Custom optical filters can be applied in the following ways, which include:

  • Laser experiments: They are used in the production of laser safety glasses to protect the eyes from the laser radiations. They filter a small range of wavelengths so users can see their surroundings, which are working on an experiment when the laser is on.
  • For artistic glass jewelry so that only a selected wavelength of light is allowed in the showcase and is used to add an effect like changing the color of light in the glass.
  • Projectors.
  • Fluorescence microscopy etc.