Short and long wave pass linear variable edge filters backed by decades of expertise, enabling a wide range of simpler and tunable optical systems.
Linear Variable Edge Filters
Linear variable edge filters provide smooth, position‑dependent cutoff control for compact optical systems. They can be either a Continuously Variable Short‑Wave Pass (LVSWP) – transmitting shorter wavelengths while blocking longer ones – or a Continuously Variable Long‑Wave Pass filter (LVLWP), where longer wavelengths are transmitted and shorter ones are rejected.
By translating the filter relative to the light path, you tune the cutoff wavelength continuously across the device. Linear variable edge filters provide the following benefits:
- Fast, cutoff tuning by simple translation
- Compact alternative to multiple discrete edge filters
- High transmission in the passband with steep, well‑defined edges
- Ideal for versatile fluorescence systems, tunable wavelength scanners and order sorting in spectrometers
How to build a tunable bandpass filter?
By combining a CVLWP with a corresponding CVSWP, a tunable Bandpass Filter can be implemented where both center wavelength and bandwidth are tunable.
Watch this video to see how the linear variable edge filters work and how to combine them to form a tunable bandpass filter.
Linear Variable Short-Wave Pass Filter product specifications
Below you can explore a selection of products we have manufactured. Some are available from stock, while others are made to order.
We work closely with our customers to design customized filters tailored to the specific needs of each application.
| λ50% min (nm) | λ50% max (nm) | Product number | Coresponding CV LWP | Max dimensions | Data sheet |
|---|---|---|---|---|---|
| 320 | 850 | LF102474 | LF102475 | 60 mm x 15 mm x 3 mm |  |
| 386 | 1005 | LF104555 | LF104550 | 110 mm x 17 mm x 2 mm | |
| 395 | 815 | LF104557 | LF104558 | 88 mm x 11 mm x 2 mm | |
| 410 | 652.5 | LF104561 | LF104559 | 82,4 mm x 26,5 mm x 0,9 mm | |
| 652.5 | 895 | LF104562 | LF104560 | 82,4 mm x 26,5 mm x 0,9 mm | |
Linear Variable Long-Wave Pass Filter product specifications
Below you can explore a selection of products we have manufactured. Some are available from stock, while others are made to order.
We work closely with our customers to design customized filters tailored to the specific needs of each application.
| λ50% min (nm) | λ50% max (nm) | Product number | Coresponding CV SWP | Max dimensions | Data sheet |
|---|---|---|---|---|---|
| 310 | 850 | LF102475 | LF102474 | 60 mm x 15 mm x 3 mm | |
| 365 | 785 | LF104558 | LF104557 | 88 mm x 11 mm x 2 mm | |
| 383 | 1000 | LF104550 | LF104555 | 110 mm x 17 mm x 2 mm | |
| 410 | 652.5 | LF104559 | LF104561 | 82,4 mm x 26,5 mm x 0,9 mm | |
| 652.5 | 895 | LF104560 | LF104562 | 82,4 mm x 26,5 mm x 0,9 mm | |
Product example: LVSWP (LF104562)
Continuously Variable Short-Wave Pass Filter for the visible-nir wavelength range from 520 nm to 900 within.
- Filter edge monotonously increasing from 652.5 nm to 895 nm within 66.6 mm
- Average passband transmittance larger than 92%
- Average rejection-band blocking of OD4 (> 20 nm from 50% edge wavelength.
Typical applications of Linear Variable Edge filters
Wavelength scanner/mono-chomator
When combined with a broadband light source, a a set of CVSWP and CVLWP filters can be used to create a tunable filter. This allows the selection of center wavelength and bandwidth by translating the filter along the long edge of the substrate.
Read how to create tunable filters using linear variable filters in our tech note here.
EPI-fluorescence
For EPI-Fluorescence applications, our Variable Edge Filters are often combined with a Continuously Variable Dichroic. If an extended blocking range is required, this can be achieved by inserting Homogeneous Blocking Filters in the light path at certain wavelengths. Read more about linear variable filter sets for epi-fluorescence here..
Frequently asked questions about Linear Variable Bandpass Filters
What advantages do linear variable edge filters offer compared to fixed edge filters?
Linear variable edge filters provide tunable cutoff control in a single compact component, eliminating the need for multiple fixed edge filters. By translating the filter, you can select any cutoff wavelength across its range, enabling flexible system design, rapid wavelength optimization, and simpler optical layouts. This reduces component count, saves space, and supports compact, high‑performance instruments where spectral agility is essential.
Can linear variable edge filters be customized for specific wavelength ranges and geometries?
Yes. Delta Optical Thin Film offers custom wavelength ranges, gradients, substrate sizes, and blocking performance. Filters can be optimized depending on your system requirements.
What applications benefit most from linear variable edge filters
Linear variable edge filters are widely used for
- wavelength scanning/selection in monochromators for analytical spectroscopic instruments
- tunable emission and excitation filters for EPI fluorescence microscopes
- order sorting in fixed-grating spectrometers (LVLWP are used for this application)
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