Linear Variable Filter (LVF)

The so-called linear variable filter is "linear" because its spectral characteristics are different at different positions and change linearly with the change of spatial position. Linear variable filter has the advantages of wavelength variable, channel optional, stable performance, etc. Due to the use of ion assisted method or ion beam sputtering method and other processes, by plating on the substrate surface of the multi-layer thickness of the film system to form a wedge film, so the spectral characteristics of linear change.

Compared with the traditional narrow band filter, the linear variable filter has nearly continuous spectral channel, so the linear variable filter can obtain higher spectral resolution. Compared with prism and grating spectral imager, linear Variable filter based spectral imager has the characteristics of high integration, high stability and high resolution, compact structure, small volume and light weight, and low development and manufacturing cost, so it has a good application prospect. Linear variable filters can also be used in portable spectrometer, grating secondary light separation/termination, laser mirror design and other fields.

LVF is a new type of spectral component developed after prism, grating and a variety of recently developed spectral components. Compared with prism, grating and other traditional spectral components, LVF has the advantages of small volume, multiple passbands, and arbitrary design of passband position. Because LVF can be combined with CCD/CMOS detector array to form a detector that can recognize spectrum, greatly simplify the spectral system, improve the reliability, stability and optical efficiency of the instrument, and attract more and more attention. The LVF as the core component of the spectrometer has been successfully applied to aerospace, field detection, atmospheric monitoring, food safety monitoring, biological fluid analysis, multi/high/hyperspectral imaging and many other fields.

Application:

Spectral imaging technique

Compared with prism and grating spectral imager, linear gradient filter based spectral imager has the characteristics of high integration, high stability and high resolution, compact structure, small volume and light weight, and low development and manufacturing cost, so it has a good application prospect.

Linear gradient filters can also be used in portable spectrometer, grating secondary light separation/cut-off, laser mirror design and other fields.