Andover Edge Filters

Edge filters are optical components that provide a sharp transition between transmitting and blocking regions of the spectrum.

They come in two main types: Long Wave Pass (LWP) filters, which transmit longer wavelengths while blocking shorter ones, and Short Wave Pass (SWP) filters, which do the opposite. These filters are characterized by their cut-on/off wavelength, transition slope, and rejection level, making them essential for precise wavelength separation in various optical systems.

LWP filters allow wavelengths longer than a specific cutoff to pass through, effectively blocking shorter wavelengths. Conversely, SWP filters transmit shorter wavelengths while blocking longer ones. The choice between LWP and SWP filters depends on the application's spectral requirements.

Edge filters are defined by three main parameters:

• Cut-on/off Wavelength: The specific wavelength at which the filter transitions from blocking to transmitting light (or vice versa).

• Slope: The steepness of the transition between the blocking and transmitting regions.

• Rejection Level: The degree to which unwanted wavelengths are attenuated in the blocking region.

Edge filters are widely employed in applications requiring precise spectral separation, including:

• Fluorescence Microscopy: To isolate specific fluorescence signals.

• Raman Spectroscopy: For blocking excitation light while transmitting Raman-scattered light.

• Laser Systems: To manage and separate laser wavelengths.

• Astronomy: For filtering specific spectral lines from celestial sources.

Yes, Andover Corporation offers custom-designed edge filters tailored to specific wavelength requirements, transition slopes, and rejection levels.

Utilizing magnetron-sputtered hard oxide coatings on precision optical substrates, Andover excels at producing filters with exceptional environmental stability and durability, suitable for a wide range of demanding applications.