What is absorption filter and interference filter?

Absorption Filter

Absorption filters selectively absorb certain wavelengths of light while transmitting others. They are made from glass or plastic that is doped with various substances to block specific wavelengths. These filters are commonly used in photography, lighting, and various scientific applications.

Key Features:

  • Material: Made from colored glass or plastic.
  • Function: Absorbs unwanted wavelengths of light.
  • Applications: Photography, scientific research, and lighting.

Interference Filter

Interference filters, also known as dichroic filters, operate on the principle of optical interference. They consist of multiple thin layers of dielectric material deposited on a substrate. These layers create constructive and destructive interference for different wavelengths of light, allowing the filter to selectively transmit or reflect specific wavelengths.

Key Features:

  • Construction: Multiple thin layers of dielectric material.
  • Function: Uses optical interference to selectively transmit or reflect light.
  • Applications: Fluorescence microscopy, astronomy, and telecommunications.

Comparison Table

Feature Absorption Filter Interference Filter
Principle Absorption of light Optical interference
Material Colored glass or plastic Dielectric layers on substrate
Wavelength Selection Based on material composition Based on layer thickness and composition
Applications Photography, scientific research Microscopy, astronomy, telecommunications
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