Ultra-Narrow Linear Variable VIS Bandpass Filter

16 Apr 2015

Delta Optical Thin Film has lifted the application range of variable filters to new levels by introducing a new powerful type of linear variable filter (LVF)

Since Delta Optical Thin Film A/S offered the first linear variable filters in 2010, development never stopped, and the next steps were a linear variable dichroic, a linear variable UV band pass filter, linear variable VIS and NIR band pass filters and several linear variable order sorting filters.

The new ultra-narrow linear variable VIS band pass filter extends the application range of LVF largely. It was possible to decrease the bandwidth to only 1% of the center wavelength. The new LVVISBP was presented to the public during the BiOS Expo and Photonics West 2015.

A complete range of linear variable filters

A Linear Variable Bandpass Filter is a wedged filter, whose spectral properties vary linearly along the length of the filter. It is possible to adjust the center wavelength by sliding the filter with respect to the incident light.

A single LVF can replace a number of dedicated filters in an instrument and decrease complexity and cost. This opens up for new design possibilities of analytical and diagnostic instruments such as spectrometers. Delta Optical Thin Film’s Linear Variable Filters are especially suited for applications in spectroscopy and fluorescence detection, for example in micro plate readers.

Superior UHC production technology

Besides setting new standards in transmission level and edge steepness, the filters offer blocking levels better than OD 3 over the complete reflection range or even OD 5 by placing two filters in series.

The filters are coated on single quartz substrates for minimal auto-fluorescence and high laser damage threshold. All of Delta Optical Thin Film’s LVF are coated with ultra-hard surface coatings that offer much higher packing density than traditional hard coatings.

The benefits of UHC are best spectral stability, increased lifetime, optimal mechanical stability and minimal water uptake. This brings use of advanced filter technology out of the laboratory and into the field.

Fact box – Linear Variable Filters made by Delta Optical Thin Film