647.1 nm Ultrasteep Raman Long-Pass Filter

The MP-LPF-647 is an ultra-steep-edge long-pass filter specifically designed for 647.1 nm laser systems. Employing high-performance multi-layer dielectric coating technology, it provides efficient rejection of the 647.1 nm laser line and short-wavelength background light, while ensuring excellent transmission for Raman scattered light, fluorescence signals, and other long-wavelength radiation above the cut-off edge. The filter offers a blocking depth of OD > 6 at the 647.1 nm laser wavelength and an average transmittance greater than 93% over the 655.5-1459.6 nm band. With an ultra‑narrow transition band of only 6.5 nm and an ultra-steep cut-off edge, it effectively improves the detection efficiency of near-laser-line Raman signals, making it widely applicable in Raman spectrometers, laser analysis, and precision optical systems.