661 nm Bandpass Filter

This product is a high-performance bandpass filter with a center wavelength of 661 nm, manufactured using precision dielectric multilayer coating technology. It is designed for fluorescence detection, laser optics, and precision imaging systems. The filter exhibits an average transmittance greater than 90% over the 651-671 nm passband, providing excellent in-band transmission and broad-band rejection. It offers high-level stray-light suppression across the 200-1200 nm range, with a blocking depth of OD ≥ 6 in the critical 440-640 nm region, effectively improving system signal-to-noise ratio and detection accuracy. The filter features a full width at half maximum (FWHM) of 26.3 nm, low scattering, high spectral stability, and excellent environmental reliability. It is widely used for detecting fluorophores such as Cy5, Alexa Fluor 647, and APC, as well as in laser Raman spectroscopy, biomedical imaging, fluorescence microscopy, flow cytometry, and analytical instruments for high-precision optical systems.