Different Types of Optical Filters

1. By Spectral Function (Most Common)

1. Bandpass Filter

   Only transmit a specific narrow wavelength range, block all others.

   
   

2. Longpass Filter (LP)

   Transmit longer wavelengths, block short wavelengths.

   
   

3. Shortpass Filter (SP)

   Transmit shorter wavelengths, block long wavelengths.

   
   

4. Notch Filter / Rejection Filter

   Block one specific wavelength band, transmit all others.

   
   

5. Dichroic Filter / Beam Splitter Filter

   Reflect one waveband, transmit another; used for light splitting/combining.

   
   

6. Neutral Density Filter (ND Filter)

   Evenly reduce light intensity across full spectrum, no color distortion.

   
   

7. Color Glass Filter

   Made of dyed optical glass, low cost, stable performance.

   
   

2. By Working Principle

• Thin Film Coated Filter: High precision, steep cut-off, industrial mainstream

• Absorption Filter: Simple structure, low price, poor blocking effect

• Interference Filter: Based light interference, high spectral accuracy

• Polarizing Filter: Filter polarized light, control light polarization direction

3. By Application Wavelength Range

• UV Optical Filter (180–400 nm)

• Visible Light Filter (400–700 nm)

• Near Infrared Filter (700–2500 nm)

• Mid/Far Infrared Filter

4. Special Functional Filters

• IR Cut Filter (IRCUT)

  Block infrared light, restore true color for camera imaging.

  
  

• Laser Line Filter

  Single wavelength transmission, laser positioning & detection use.

  
  

• Anti-glare / Infrared Cut-off Filter

  Security monitoring, vehicle lens dedicated.