Longpass Filter is a transparent optical element designed to transmit light of longer wavelengths in selection than the cut-on wavelength while blocking or attenuating shorter wavelengths. The fundamental function of a long pass filter is to allow light beyond a specific wavelength, known as the "cuton wavelength," to pass through while obstructing shorter wavelengths. For example, an IR longpass filter permits infrared light to pass while blocking visible and ultraviolet light. This is achieved through utilizing specialized coatings or materials that are capable of the discrimination of the designated wavelengths. Long pass filters provide flexible control over the light spectrum, enhancing image qualities and facilitating various optical processes. The wide transmission range and versatile functions of longpass filters make them essential components in a wide range of optical applications, such as photography, spectroscopes, microscopes, and sensor technologies.

This page specifies Shanghai North Optics's off-the-shelf longpass filters, while we also offer tech support and design service for custom longpass optical filters, where our extensive range of dimensions, and transmission wavelengths cater to your individual requirements. The blocking wavelength ranges of our longpass filters extend from UV to IR, accommodating numerous spectral operations. Our longpass filters offer great steepness of the transition between transmission and blocking regions. Exploiting advanced production techniques and rigorous inspection procedures, we ensure optimized durabilities and exceptional optical transmission for our users across various industries.