Custom Optical 740nm BandPass Filter Glass

Custom Optical 740nm BandPass Filter Glass   A 740nm bandpass filter is a highly specialized optical filter designed to transmit a very narrow, specific band of light centered at 740 nanometers (nm) while rejecting all other wavelengths above and below this band. Light at 740nm is in the near-infrared (NIR) region of the electromagnetic spectrum, just beyond the range of human vision. Specification：   Key Operating Principle   The filter works on the principle of thin-film interference. It is constructed by depositing dozens of alternating, precise layers of materials with different refractive indices (e.g., SiO₂, TiO₂, Ta₂O₅) onto a glass substrate.   · Constructive Interference: The thickness of each layer is controlled to be a fraction of the target wavelength. For light near 740nm, the reflections from all these layer interfaces interfere constructively, allowing that light to pass through. · Destructive Interference: For wavelengths significantly different from 740nm, the ref…