Homogeneous Blocking Filters

Delta Optical Thin Film has created a range of Homogeneous Blocking Filters, designed to enhance the out-of-band blocking of some of our Continuously Variable Filters. These out-of-band blocking filters offer high transmission in a wide wavelength range while blocking other wavelengths in the complete silicon sensor wavelength range (300 – 1100 nm). The out-of-band blocking filters are designed to be switched in and out of the beam at certain wavelengths as shown on the figure below.

Figure 6: Extending the blocking range of a tunable bandpass filter with a wide band homogeneous bandpass filter.

A Continuously Variable Long-Wave Pass (CVLWP) and a Continuously Variable Short-Wave Pass (CVSWP) filter pair is used to create a tunable filter as described on our product page about Continuously Variable Edge filters.

The two blocking filters on the figure are are essentially wide-bandpass filters that transmit nearly 100% in the passband and reject typically OD5-6 outside the passband. The blocking filters can be slided into the beam path one at a time depending on the wavelength range in use.

The table below lists a number of out-of-band blocking filters that we have manufactured. If none of the examples match your specific needs we are happy to discuss a customized filter for you.

Product specifications

λcenter (nm)FWHM (nm)Tpeak (%)Product numberMax size Data sheet
48022093LF10455180 mm x 55 mm x 1 mmDownload_15px
55010092LF101761Round diameter 25 mm x 2 mmDownload_15px
55019090LF103000Round diameter 25 mm x 2 mmDownload_15px
55520090LF102851Round diameter 25 mm x 2 mmDownload_15px
55829594LF10455280 mm x 55 mm x 1 mmDownload_15px
67036095LF10455380 mm x 55 mm x 1 mmDownload_15px
77836590LF103001Round diameter 25 mm x 2 mmDownload_15px
82742595LF10455480 mm x 55 mm x 1 mmDownload_15px

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