Linear Variable Filters

Linear Variable Filter

A Linear Variable Filter (LVF) is a wedged filter that has spectral properties varying linearly with the direction of the wedge. 

We are proud to announce that DELTA has the capabilities to design and manufacture LVF filters with different linear slopes for application in UVA, VIS and part of NIR. Present filters are mainly targeted towards the spectral range 300nm - 850nm.

A single LVF in example may replace a number of dedicated filters in an instrument. It is possible to adjust the position of the edge by sliding the filter.

DELTAs new Linear Variable Filters are especially suited for application in spectroscopy.

• LVLP [λ1-λ2] - Linear Variable Long Wave Pass filter.
• LVSP [λ1-λ2] - Linear Variable Short Wave Pass filter.

The Linear Variable filters feature:

• Ultra-Hard-Coated filters.
• Standard dimension is a plate 15x60x3mm.
• The wavelengths [λ1-λ2] given in the denomination are the wavelengths of the edge of the filter at the lowest spectral point (minimum thickness of the wedge) and the highest spectral point (maximum thickness of the wedge).
• The data sheets show typical transmission curve for unpolarized light with AOI=0 degrees at different wedge positions.

For further information, please do not hesitate to contact us.

Specifications of Linear Variable Filters

* The steepness of the slope is defined as α = (λT=80% - λT=5% )/λc.

** Linear dispersion is a measure of the deviation from the linearity.