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

Speckle

<<<  |  >>>  |  Feedback

Buyer's Guide

Use the RP Photonics Buyer's Guide to find suppliers for photonics products! You will hardly find a more convenient resource.

Definition: light patterns resulting from the reflection of coherent light at rough surfaces

The term speckle refers to a random granular pattern which can be observed e.g. when a highly coherent light beam (e.g. from a laser) is diffusely reflected at a surface with a complicated (rough) structure, such as a piece of paper, white paint, a display screen, or a metallic surface. This phenomenon results from the interference of different reflected portions of the incident beam with random relative optical phases. Even minor changes of the conditions, such as of the illuminated spot or the direction of the incident laser beam, can change the detailed shape of a speckle pattern.

Speckle patterns can severely degrade the image quality of laser projection displays, or disturb position measurements with laser pointers. Speckle can often be avoided, e.g. by using a light source with sufficiently large optical bandwidth (short coherence length) such as a superluminescent source. For projection displays, one may also work with an optimized screen. However, there are also applications of speckle, e.g. in speckle interferometry.

The complicated intensity patterns observed at the ends of multimode fibers are also sometimes called speckle. They result from the interference of many propagation modes, where the relative phases depend on the detailed launching conditions.

Bibliography

[1]J. W. Goodman, “Some fundamental properties of speckle”, J. Opt. Soc. Am. 66 (11), 1145 (1976)
[2]K. Creath, “Phase-shifting speckle interferometry”, Appl. Opt. 24 (18), 3053 (1985)
[3]J. C. Dainty, Laser Speckle and Related Phenomena, Springer, Berlin (1975)

See also: coherence, coherence length, linewidth, superluminescent sources, Spotlight article 2007-06-24

Category: general optics

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!

arrow

Have you seen the
RP Photonics Buyer's Guide?

It lists many hundreds of suppliers for photonics products, and is just one mouse click away from the extremely popular Encyclopedia of Laser Physics and Technology:

Our Buyer's Guide is what you need:

And surely you will remember where to find this useful resource again!

Suppliers: get your free entries, and enhanced visibility with paid entries.

Tailored Training Courses

Within one or two days, a tailored training course at your location can boost the competence of your team. An investment which can pay back very rapdily!

New Fiber Optics Software!

RP Fiber Calculator software

RP Fiber Calculator – a convenient tool for calculations on optical fibers -- offered for free within the 10-year anniversary of RP Photonics, and also as a PRO version with even more powerful features!

This resource is provided by
RP Photonics Consulting GmbH.

You can get technical consulting from the author, Dr. Rüdiger Paschotta.

Read a random article every day in order to steadily learn about photonics!

Numerical Modeling

Understand your devices, avoid wasting resources, minimize time to market!

Get into efficient modeling with RP Photonics software or utilize advanced technical expertise via consultancy.