650nm Bandpass Filter for Machine Vision

650nm Bandpass Filter for Machine VisionThis 650 nm narrow band pass filter (FWHM 20 nm, Ø8 mm × 1.1 mm) transmits a narrow red spectral band suitable for diode-laser or LED illumination while effectively suppressing stray light. The term "bandpass" is characterized by the full width at half maximum (FWHM) and out-of-band optical density (OD), where higher OD values indicate lower transmission of unwanted wavelengths, calculated as OD = −log10 T. The filter employs durable, ion-beam-sputtered multilayer coatings that offer superior stability in both passband and blocking performance compared to conventional soft coatings. Additionally, anti-reflection (AR) coatings on the outer surfaces minimize Fresnel losses to less than 0.5% per surface within the visible spectrum. In machine vision applications, combining this filter with common 650/660 nm laser or LED sources significantly enhances signal-to-noise ratio by attenuating ambient light components. It is important to note that interfe…