Featured Research

from universities, journals, and other organizations

Nonlinear optics: Now in the terahertz range

Date:
June 13, 2012
Source:
Technical University of Denmark (DTU)
Summary:
Researchers have recently reported on the direct observation of a nonlinear-optical effect, occurring in the regime of single-cycle pulse of light at terahertz (THz) frequencies. They used a doped semiconductor as an efficient nonlinear medium, where the THz-range optical nonlinearity arises from the response of free-electron plasma to THz electric fields.

As the field strength in the incident THz pulse (the one on the left) grows, the THz pulse transmitted through the semiconductor (the one on the right) experiences a larger time delay due to self-phase modulation.
Credit: DTU

The researchers at DTU Fotonik, Max Planck Institute for Polymer Research -- MPIP (Mainz, Germany), and SLAC Linear Accelerator Laboratory (California, USA) have recently reported on the direct observation of a nonlinear-optical effect, occurring in the regime of single-cycle pulse of light at terahertz (THz) frequencies. In their paper, published in Physical Review B , they used a doped semiconductor as an efficient nonlinear medium, where the THz-range optical nonlinearity arises from the response of free-electron plasma to THz electric fields.

Related Articles


The single-cycle pulses of THz light, propagating through such a medium, experienced an effect called the self-phase modulation (SPM), which led to the nonlinear reshaping and time delay of the THz pulses. The SPM is one of the most important effects in nonlinear optics. It is used in numerous applications, ranging from supercontinuum generation for biophotonics imaging to ultra-high speed optical signal processing in telecom systems.

Single-cycle pulses, irrespective of the frequency range to which they belong, inherently have an extremely broad spectral bandwidth covering many octaves of frequencies. Unlike the single-cycle pulses at optical frequencies, the THz pulses can be easily generated and detected in the time-domain using conventional femtosecond lasers. One of the discoveries in this work was the coexistence of both positive and negative refractive index nonlinearity within the broad spectrum of a single-cycle THz pulse. This is quite a unique observation for nonlinear optics in general, which demonstrates a great potential of using THz pulses as accessible model tools for study of single-cycle nonlinear optical effects.


Story Source:

The above story is based on materials provided by Technical University of Denmark (DTU). Note: Materials may be edited for content and length.


Journal Reference:

  1. Dmitry Turchinovich, Jørn Hvam, Matthias Hoffmann. Self-phase modulation of a single-cycle terahertz pulse by nonlinear free-carrier response in a semiconductor. Physical Review B, 2012; 85 (20) DOI: 10.1103/PhysRevB.85.201304

Cite This Page:

Technical University of Denmark (DTU). "Nonlinear optics: Now in the terahertz range." ScienceDaily. ScienceDaily, 13 June 2012. <www.sciencedaily.com/releases/2012/06/120613102128.htm>.
Technical University of Denmark (DTU). (2012, June 13). Nonlinear optics: Now in the terahertz range. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2012/06/120613102128.htm
Technical University of Denmark (DTU). "Nonlinear optics: Now in the terahertz range." ScienceDaily. www.sciencedaily.com/releases/2012/06/120613102128.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Microsoft Adds Robot Guards, Ushers In Sci-Fi Apocalypse

Newsy (Nov. 23, 2014) — Microsoft has robotic security guards working at its Silicon Valley Campus. Video provided by Newsy
Powered by NewsLook.com
Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

AFP (Nov. 21, 2014) — Toyota presented its hydrogen fuel-cell compact car called "Mirai" to US consumers at the Los Angeles auto show. The car should go on sale in 2015 for around $60.000. It combines stored hydrogen with oxygen to generate its own power. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) — In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
Powered by NewsLook.com
Raw: Paralyzed Marine Walks With Robotic Braces

Raw: Paralyzed Marine Walks With Robotic Braces

AP (Nov. 21, 2014) — Marine Corps officials say a special operations officer left paralyzed by a sniper's bullet in Afghanistan walked using robotic leg braces in a ceremony to award him a Bronze Star. (Nov. 21) Video provided by AP
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