Featured Research

from universities, journals, and other organizations

Understanding And Controlling Optical Damage Caused By Lasers On Crystals

Date:
July 7, 2008
Source:
Universidad Autónoma de Madrid
Summary:
A new study has advanced current understanding as well as the control of optical damage in crystals, offering new ways to increase light-power output of future optical integrated circuits. Many of the lasers used today, both in scientific or technological applications have such a high light output power that the light itself damages or even destroys the crystals used to control, guide or manipulate it inside photonic devices (devices that only work with light).

Illustration of the progressive degradation of a high intensity laser beam when propagating through a crystalline waveguide showing optical damage caused by photorefractive effect.
Credit: Image courtesy of Universidad Autónoma de Madrid

A new study undertaken by the non lineal optics and wave guides research group belonging to the department of Material Science of the UAM has advanced current understanding as well as the control of optical damage in crystals, offering new ways to increase light-power output of future optical integrated circuits.

Many of the lasers used today, both in scientific or technological applications have such a high light output power that the light itself damages or even destroys the crystals used to control, guide or manipulate it inside photonic devices (devices that only work with light).

Even at not so high powers, distortion effects take place in crystalline materials that change the characteristics of the laser beam as it propagates through the material. This effect is called optical damage and is mainly caused by the photorefractive phenomenon, which is caused by the presence of defects or atomic impurities, the electrons of which are excited by the light and scatter within the material. This movement of electrons creates internal electrical fields that alter the refractive index of electrotropic crystals, hence affecting the propagation of the light through them.

In many cases, the photorefractive effect is useful. It grants control over the propagation of light in a crystal by means of other light beams and also allows the storage of information as holograms. Nevertheless, at high light intensities, the photorefractive effect strongly degrades the light beam, a fact which currently introduces great difficulties for the arrival of new photonic integrated devices such as micro lasers, electro optical modulators, or frequency transducers that require higher efficiencies at higher intensities.

For many years, researchers from the non lineal optics and wave guides group of the department of Material Science of the UAM have studied the response of one of the most used crystals in the history of photonics, lithium niobate, to intense laser light. Their knowledge has made possible the development of a model that explains the optical damage through photorefractive effects in this crystal but it can also be applied to other electro-optic crystals.

The most relevant idea of this model is based on new discoveries relating to the atomic defects of crystals that influence the photo refraction at high light intensities as well as the capacity to amplify optical noise.

With this model the minimum light intensity (Sensory threshold) at which the damage appears, as a function of defect concentration, temperature and other crystal properties can be predicted. The study also offers scientists and physicists a guide to optimize the properties of the crystal and the design of devices, enabling a rise of the laser light intensity in the crystal to 106 W/cm2, which represents an increase of the damage intensity threshold of a normal crystal by a factor of 10,000.

This study was carried out by the researchers Mercedes Carrascosa, Angel García Cabañes, José Manuel Cabrera and the doctorate students Javier Villarroel y Jesús Carnicero from the department of Material Science of the UAM.


Story Source:

The above story is based on materials provided by Universidad Autónoma de Madrid. Note: Materials may be edited for content and length.


Journal Reference:

  1. M. Carrascosa, J. Villarroel, J. Carnicero, A. García-Cabañes, and J. M. Cabrera Optics Express. Understanding light intensity thresholds for catastrophic optical damage in LiNbO3. Optics Express, Vol. 16, Issue 1, pp. 115-120 DOI: 10.1364/OE.16.000115

Cite This Page:

Universidad Autónoma de Madrid. "Understanding And Controlling Optical Damage Caused By Lasers On Crystals." ScienceDaily. ScienceDaily, 7 July 2008. <www.sciencedaily.com/releases/2008/07/080702172930.htm>.
Universidad Autónoma de Madrid. (2008, July 7). Understanding And Controlling Optical Damage Caused By Lasers On Crystals. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2008/07/080702172930.htm
Universidad Autónoma de Madrid. "Understanding And Controlling Optical Damage Caused By Lasers On Crystals." ScienceDaily. www.sciencedaily.com/releases/2008/07/080702172930.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Thanks, Marty McFly! Hoverboards Could Be Coming In 2015

Newsy (Oct. 21, 2014) — If you've ever watched "Back to the Future Part II" and wanted to get your hands on a hoverboard, well, you might soon be in luck. Video provided by Newsy
Powered by NewsLook.com
Robots to Fly Planes Where Humans Can't

Robots to Fly Planes Where Humans Can't

Reuters - Innovations Video Online (Oct. 21, 2014) — Researchers in South Korea are developing a robotic pilot that could potentially replace humans in the cockpit. Unlike drones and autopilot programs which are configured for specific aircraft, the robots' humanoid design will allow it to fly any type of plane with no additional sensors. Ben Gruber reports. Video provided by Reuters
Powered by NewsLook.com
Graphene Paint Offers Rust-Free Future

Graphene Paint Offers Rust-Free Future

Reuters - Innovations Video Online (Oct. 21, 2014) — British scientists have developed a prototype graphene paint that can make coatings which are resistant to liquids, gases, and chemicals. The team says the paint could have a variety of uses, from stopping ships rusting to keeping food fresher for longer. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com
Portable Breathalyzer Gets You Home Safely

Portable Breathalyzer Gets You Home Safely

Buzz60 (Oct. 21, 2014) — Breeze, a portable breathalyzer, gets you home safely by instantly showing your blood alcohol content, and with one tap, lets you call an Uber, a cab or a friend from your contact list to pick you up. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins