RP Photonics logo
RP Photonics
Encyclopedia
Consulting Software Encyclopedia Buyer's Guide

Short address: rpp-con.com

Dr. Paschotta, the founder of RP Photonics, supports your R & D with his deep expertise. Save time and money with efficient support!

Short address: rpp-soft.com

Powerful simulation software for fiber lasers and amplifiers, resonator design, pulse propagation and multilayer coating design.

Short address: rpp-enc.com

The famous Encyclopedia of Laser Physics and Technology provides a wealth of high-quality scientific and technical information.

Short address: rpp-bg.com

In the RP Photonics Buyer's Guide, you easily find suppliers for photo­nics products. As a supp­lier, you can profit from enhanced entries!

Learn on lasers and photonics every day!
VL logo part of the
Virtual
Library

Lyot Filters

<<<  |  >>>  |  Feedback

Buyer's Guide

The ideal place to find suppliers for photonics products: high-quality information, simple and fast, respects your privacy!

3 suppliers for Lyot filters are listed.

Your are not yet listed? Get your entry!

Definition: optical filter devices based on birefringence, exhibiting a wavelength-dependent transmission

German: Lyot-Filter

Category: photonic devices

How to cite the article; suggest additional literature

A Lyot filter is a kind of optical filter, i.e. an optical device with a wavelength-dependent power transmission. It consists of a sequence of birefringent crystalline plates (e.g. of quartz) and polarizers. The birefringent axis of each crystal is oriented at 45° to the axis direction of the polarizers. The light propagating in a crystal can be considered as containing two different linear polarization components, which experience a different phase delay. The relative phase delay for the two polarization components depends on the wavelength. Therefore, the loss of optical power at the subsequent polarizer is wavelength-dependent.

Lyot filter

Figure 1: A Lyot filter, consisting of a sequence of birefringent crystals (BC) and polarizers (P).

For a device with a single birefringent crystal, the power transmission versus optical frequency can be described with an approximately sinusoidal oscillation. (Chromatic dispersion causes some deviation from an exact sinusoidal oscillation.) By combining multiple crystals with different thickness, a sharper filter function can be realized. According to the Lyot design (invented by Bernard Lyot), the thickness of each crystal is half the thickness of the previous one (Figure 1). In this way, a small transmission bandwidth combined with a large period of the transmission peaks is possible.

filter function of a Lyot filter

Figure 2: Transmission function of a Lyot filter containing three quartz plates, with thickness values of 5, 2.5, and 1.25 mm.

A Lyot-type filter with electrically tunable transmission peaks can be realized by using a Pockels cells instead of the passive birefringent crystals.

For wavelength tuning of lasers, one mostly uses birefringent tuners based on a similar principle, but not containing polarizers, since the losses via the Fresnel reflection for s-polarized light are sufficiently strong.

Bibliography

[1]B. Lyot, “Optical apparatus with wide field using interference of polarized light”, C. R. Acad. Sci. Paris 197, 1593 (1933)
[2]O. Aharon and I. Abdulhalim, “Liquid crystal Lyot tunable filter with extended free spectral range”, Opt. Express 17 (14), 11426 (2009)
[3]K. Ölgören and F. Ö. Ilday, “All-fiber all-normal dispersion laser with a fiber-based Lyot filter”, Opt. Lett. 35 (8), 1296 (2010)

(Suggest additional literature!)

See also: birefringent tuners, optical filters

How do you rate this article?

Your general impression: don't know poor satisfactory good excellent
Technical quality: don't know poor satisfactory good excellent
Usefulness: don't know poor satisfactory good excellent
Readability: don't know poor satisfactory good excellent
Comments:

Found any errors? Suggestions for improvements? Do you know a better web page on this topic?

Spam protection: (enter the value of 5 + 8 in this field!)

If you want a response, you may leave your e-mail address in the comments field, or directly send an e-mail.

If you like our website, you may also want to get our newsletters!

cover of SPIE Field Guide cover of SPIE Field Guide cover of SPIE Field Guide

Dr. Paschotta, author of this encyclopedia, has also published three books in the SPIE Field Guide series:

- Field Guide to Lasers

- Field Guide to Laser Pulse Generation

- Field Guide to Optical Fiber Technology

You can order these books on the SPIE website – just click on one of the images.

arrow

Thin-film Optics Software

RP Coating is a most versatile software for thin-film design. Analyze and optimize a wide range of devices:

coating design

Further features:

Use RP Coating to quickly become a thin-film expert!

– Show all banners –

– Get your own banner! –