Optical Filters
Shortpass Filters, also called Shortpass Edge Filters, are optical elements that transmit wavelengths shorter than a specific wavelength (the cut-off wavelength) of the filter. The thin-film coatings and absorptive colored glass are engineered to interact with the incoming light and provide a cut-off slope establishing the transition between a region of high rejection and a region of high transmission. Shortpass filters consist of two parts in main: a substrate and a stack of dielectric thin films. The substrate acts as a support for the dielectric stack and is often made of materials like glass or fused silica. The dielectric stack comprises alternating thin films of high and low refractive index coating materials, such as titanium dioxide and silicon dioxide. When light enters a shortpass filter, it encounters the dielectric stack. The thickness and refractive indices of these dielectric thin films are designed to create interference patterns. This interference causes destructive interference for longer wavelengths, resulting in their reflection or absorption, while shorter wavelengths experience constructive interference and are transmitted through the filter.
One of the most crucial subcategories of shortpass filters is UV shortpass filters, designed to transmit ultraviolet (UV) light while blocking longer wavelengths. These filters are used in various applications, such as fluorescence microscopy, UV spectroscopy, and UV imaging. Shortpass filters find extensive usage in biomedical imaging, astronomy, and industrial applications.
Hangzhou Shalom EO utilizes vacuum coating facilities, the TiO2 and SiO2 coatings are formed in a circulating evaporation course. We offer stocked and custom shortpass filters. Regarding the stocked shortpass filters, a wide transmission wavelength range extending from UV to IR spectral regions is available. Regarding the custom shortpass filters, all specifications could be tailored upon your request.
