Colored optical filter

These Linear Variable Edge Filters can be used in pairs in order to create highly efficient custom bandpass filters. They have an optimum input beam diameter of 0.2 x 8.0 mm and provide OD3 blocking. Linear Variable Bandpass Filters can also be supplied. The Linear Variable Edge Filters have been designed either for individual use or for use in pairs to selectively block or transmit targeted wavelengths. They can be supplied as shortpass, longpass or dichroic filters. Longpass edge filters are able to transmit wavelengths which are greater than the cut-on wavelength. The shortpass edge filters, however, are able to transmit wavelengths shorter than the cut-off wavelength. The dichroic edge filters operate in a similar fashion to the longpass edge filters but the unwanted wavelengths are always reflected. Linear Variable Edge Filters can operate as laser-line filters or variable bandpass filter with turntable center bandwidths and wavelengths when combined. These are characterized by their interference coating which is deliberately wedged in the desired direction so as to shift the whole of the center wavelength across the substrate length.