Edge Filters vs. Notch Filters for Raman Instrumentation

by IDEX Health & Science

Should you use an edge filter or a notch filter to block the laser line in your Raman system?


RazorEdge® Edge Filter AdvantagesStopLine® Notch Filter Advantages

Shortest possible transition width,
allowing measurement of the smallest
possible Stokes shifts

Ability to measure Stokes and
Anti-Stokes shifts simultaneously
Available for popular UV laser wavelengthsGreater tunability and bandwidth
for accommodating variable laser lines


The RazorEdge edge filters and the StopLine notch filter are both available with OD>6 blocking of the laser line.  The main benefit of the RazorEdge filter is the very narrow transition width, allowing users to measure even the smallest Raman shifts. Although the StopLine notch filters do not transition as close to the laser line, they are tunable from 0° to 14°, or 1% of the laser line to allow users to shift the bandwidth in response to variable laser lines. The RazorEdge filters are tunable as well, from 0° to 8°, or 0.3% of the laser wavelength.   In addition to the greater ability to angle tune, the notch filter's dual passband allows users to measure Stokes and Anti-Stokes shifts without changing filters.