Deep ultraviolet narrow band filter

Abstract

The invention belongs to the technical field of thin film optics, and relates to a deep ultraviolet narrow band filter. The main structure of the deep ultraviolet narrow band filter comprises a base layer, a filter layer, a film layer and a protective layer. According to the deep ultraviolet narrow band filter, a design concept of the F-P band-pass filter film is used for designing a metal-mediumcombined transmission filter, a tandem metal-medium filter is selected to suppress a sideband of a long-wavelength region, an all-media filter is used for reducing the bandwidth, a multilayer film structure composed of a high refractive index material/ low refractive index material is in tandem arrangement on the basis of a double half-wave F-P interference filter structure to form an F-P filter with a simple structure, the depth cutoff in a specific deep ultraviolet wave band is achieved in a wavelength band, by changing the shape of the filter layer, the half-bandwidth of the deep ultraviolet narrow band filter is reduced to separate a selected film layer from a film system, the combination of the entire film system is represented by two selected effective interfaces, as long as the multi-beam interference of the selected film layer is considered, the optical properties of the multilayer film are solved, and the method for designing the film system is obtained.

Description

Technical field: [0001] The invention belongs to the technical field of thin-film optics and relates to a deep ultraviolet narrow-band filter. The prepared filter has narrow bandwidth and high transmittance, can realize a wide range of depth cut-off, and solves the problem of deep ultraviolet filtering. Background technique: [0002] The filter is an optical device used to select the required radiation band. The commonality of the filter is that no filter can make the image of the celestial body brighter, because all filters will absorb certain wavelengths, so that the Objects become darker. The filter is made of plastic or glass with special dyes added. The red filter can only let red light pass through, and so on. The transmittance of the glass sheet is almost the same as that of air, and all colored light can pass through, so it is transparent. Yes, but after dyeing the dye, the molecular structure changes, the refractive index also changes, and the passage of certain co...

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Problems solved by technology

In most applications, the bypass band must be suppressed: usually the short-wave bypass band can be removed by superimposing a long-wave pass absorption glass filter on the filter, although the short-wave pass absorption glass filter can effectively suppress the long-wave pass band. Sideband, but its short-wave transmittance is too low, which reduces the peak transmittance of the overall film system, and it is very difficult to cut off the filter in the range of 200nm-250nm, because there is no short-wave pass absorption in this spectral range glass filter

There are two cut-off methods in the current research, one is to increase the metal-dielectric filter, and the other is to connect the mirror in series with the filter to obtain the cut-off. The advantage is that there is no long-wave bypass passband. The disadvantage is that the peak transmittance is very low and the half width is very large, so that the cutoff and passband shape cannot be used.

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