Georgia Institute of TechnologyOptics + Photonics at Georgia Tech
Dr. Dickson and researchers in his labDr. Kippelen with graduate researcher

Ultrafast Optics

RESEARCH FACULTY

Tech Researcher
Ultrafast Optics Researchers
Meet the Georgia Tech Faculty involved in Ultrafast Optics Research.

Ultrafast optics is the study and application of optical pulses and optical phenomena with duration shorter than a few picoseconds. Ultrafast optics became possible with the invention of short pulse lasers which can now routinely produce optical pulses of a few femtoseconds (10-15). These short pulses provide the "clock" or ruler by which researchers can create and measure events which occur on the femtosecond time scale. To appreciate the precision allowed by such fast events, consider that the ratio of one second to one femtosecond is the same as the ratio of seconds elapsed since the big bang to one second.

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Continuum generation in micro-structured fiber; strong nonlinearities produce a white light continuum from a narrow band laser. The white light source is useful as a spectroscopic and frequency standard source.
(Courtesy of S. Ralph)

Ultrafast techniques have also been applied to imaging, time resolved femosecond spectroscopy and the generation and measurement of optical pulses. Ultrafast optical techniques allow the investigation of highly non-equilibrium carrier dynamics in semiconductors and ultrafast optical interactions with biological systems. Ultrafast optical methods have also allowed the generation of precision light sources for optical frequency metrology. Indeed, the recent Nobel Prize in Physics, awarded to Drs. R. Glauber, J. Hall, and T. Henesch, was, for their work using repetitive trains of ultrashort pulses which have a spectrum that consists of an evenly spaced comb consisting of thousands of sharp spectral lines.

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Detail of a micro-structured optical fiber used to generate a white light continuum from a narrow band laser.
(Courtesy of S. Ralph)

Short pulse technologies allow the generation of high peak powers, PetaWatts, for the study of the effects of very high electric fields. When combined with optoelectronic devices, ultrashort optical pulses can be used to generate and measure electrical pulses of the shortest possible durations. These signals, which have bandwidths in excess of one terahertz (1012 Hz), can be guided and used to investigate the operation of new electrical interconnects or integrated circuits, or they can be formed into radiating "terahertz beams" and used for spectroscopic applications in the far infrared.

Researchers at Georgia Tech are pursuing new means to generate, measure and apply exploit optical pulses. One of the standard technique for measuring short optical pulses, known as frequency resolved gating, FROG, was invented by a Georgia Tech researcher. Furthermore new sources of Terahertz radiation are under development, short pulse techniques are being used to understand linear and nonlinear propagation in optical fibers.