Linear Variable Filters

Linear Variable Filter

A Linear Variable Filter (LVF) is a wedged filter, whose spectral properties vary linearly.

Please refer to our Data Sheet Linear Variable Filters for details.

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

DELTA has lifted the quality of variable filters to new levels by introducing a new powerful combination of linear variable filters. DELTA offers a Linear Variable Long Wave Pass filter (LVLWP), the corresponding Linear Variable Short Wave Pass filter (LVSWP) together with a Linear Variable Dichroic. Each of the filters can be used separately. Combining LVLWP and LVSWP enables the construction of band-pass filters that can be tuned continuously with center wavelengths from 320 nm to 850 nm, with the added benefit of tunable bandwidth.

Besides setting new standards in transmission level and edge steepness, the filters offer blocking better than OD 3 over the complete reflection range. It is possible to increase the blocking to beyond OD5 by placing another linear variable filter in series.

The filters are coated on single quartz substrates for minimal auto-fluorescence and high laser damage threshold. All of DELTA's Linear Variable Filters are coated with ultra-hard surface coatings (UHC) that are also used by DELTA in traditional fluorescence filters.

DELTA's new Linear Variable Filters are especially suited for applications in spectroscopy.

Full tunability in your system by using the following Linear Variable Filters:

• Overview of our Linear Variable Filters
• Short Wavelength Pass filter: Edge to be tuned from 340 nm – 850 nm
• Long Wavelength Pass filter: Edge to be tuned from 300 nm – 850 nm
• 2G Long Wavelength Pass filter: Edge to be tuned from 300 nm – 850 nm
• Dichroic: Edge to be tuned from 320 nm – 750 nm
• UV Band Pass filter: Center wavelength to be tuned from 300 nm – 330 nm

The Linear Variable filters feature:

• Ultra-Hard-Coated filters.
• Standard dimension (LVLWP, LVSWP, LVBP) is a plate of 15 mm x 60 mm x 3 mm.
• Standard dimension (LVDichroic) is a plate of 15 mm x 60 mm x 1 mm.
• The wavelengths λ1, λ2 given in the specification 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 curves for unpolarized light with an AOI=0° at different wedge positions.

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

Specifications of Linear Variable Filters