- 25 mm Outer Diameter (Ø21.1 mm Clear Aperture)
- Longpass and Shortpass FIlters
- Excellent Suppression in Rejection Region (OD > 5)
- Transmission Direction Engraved on Edge
- Ideal as Raman Spectroscopy Filters or Emission Filters for Fluorescence Applications
Thorlabs' premium edgepass filters are high-performance filters that are very useful for isolating regions of a spectrum. These filters provide better transmission, steeper slopes, greater blocking, and increased durability when compared to our standard line of edgepass filters (see the Specs tab for comparison).
The high-performance longpass filters offer an optical density (OD) in excess of 5 in the rejection region and greater than 90% transmission from the cut-on wavelength out to 2150 nm. The shortpass high-performance filters provide an OD in excess of 5 in the rejection region and greater than 90% transmission from either 400 nm or 500 nm to the cut-off wavelength, depending on the particular item.
These edgepass filters feature durable, hard-coated dielectric coatings on UV fused silica. The film construction is essentially a modified quarter-wave stack, using interference effects to isolate spectral bands (see the Specs tab for transmission information). The coating on these filters can withstand the normal cleaning and handling necessary when using any high-quality optical component. These coatings are more dense than those on our standard filters, and that allows for only one substrate layer, and yields a more stable, longer-lasting filter.