Iridian’s nano-edge LPFs offer cut-offs of <26 cm-1, corresponding to 0.2% of the laser wavelength. This is even steeper than our market-leading ultra-steep LPF (cut-offs <40 cm-1)! These nano-edge LPFs also offer high transmittance out to 1200 nm (>90%), deep blocking at the laser line (>OD 6), and low ripple (<5%). These filters are manufactured using our state-of-the-art dielectric coating technology, producing robust and reliable thin film filters.
These extremely steep edges allow a user to access Raman modes that would be blocked by standard edge pass filters. For example, lattice modes can appear at very low Raman shifts and provide important structural information on a crystalline sample. By employing Iridian’s filters in a Renishaw InVia instrument, a mode at 15 cm-1 is clearly visible in the L-Cystine Raman spectrum.
Iridian has nano-edge LPFs at 488, 514.5, 532 and 785 nm available for purchase. Iridian is also happy to work with you to develop a solution for your specific optical filter needs. Please contact Iridian for further discussion of how our market-leading performance can benefit your Raman system.