June 2002 Meeting

“Solid State Laser Research”

Professor Richard C. Powell,
Vice President for Research and Graduate Studies
Professor of Optical Science
Optical Sciences Center
University of Arizona

 

The OSSD and the evening’s host, Steve Pappert, are privileged to present Professor Richard C. Powell, Vice President for Research and Graduate Studies & Professor of Optical Science, University of Arizona. Prof. Powell is a pioneering researcher in the field of solid state laser development and will be speaking to us on “Solid State Laser Research.” Solid state lasers have impacted and revolutionized many industries.

This talk will review the current status of solid-state lasers. Then a specific class of solid-state lasers, Raman lasers, will be discussed as a specific example of new technology development. The spectroscopic properties of the materials used in these lasers are presented and the use of these materials in shared-, coupled-, and external-resonator laser systems is described. System design parameters affecting efficiency, beam quality, and temporal pulse width are discussed. Examples will be presented of the use of these lasers for transmitters in atmospheric and marine imaging LIDAR systems and in optical amplifiers.

Also at this meeting, Murray Dunn, chairman of the 2002 San Diego Science Fair committee, will present awards for the best optics-related entries of this year’s Fair. The winners will have their winning entries on display. Please come and show your support of our future engineers and scientists.

 

About the Speaker: Richard Powell received his B.S. degree from the United States Naval Academy in 1962, and his M.S. and Ph.D. degrees in physics from Arizona State University in 1964 and 1967, respectively. During his career as a research scientist and educator, he held positions as a staff scientist at Air Force Cambridge Research Laboratories, Sandia National Laboratory, and Lawrence Livermore National Laboratory. He has held academic positions as a professor at Oklahoma State University and the University of Arizona. In addition, he has held numerous university administrative positions including Physics Department Head, Associate Dean of the College of Arts and Sciences, and Director of the Center for Laser Research at Oklahoma State University, and Director of the Optical Sciences Center and Vice President for Research and Graduate Studies at the University of Arizona.

Prof. Powell's professional field is the development and application of solid-state lasers. He is one of the founders of Lite Cycles, Inc. (http://www.litecycles.com/home.htm), a small business that sells specialized laser systems. He has authored two textbooks and over 260 review articles and scientific papers published in peer-reviewed journals.

 

REVIEW OF JUNE 2002 OSSD MEETING
By Steve Pappert

The OSSD held its final monthly meeting before the Summer 2002 break at Giovanni's Restaurant in Kearney Mesa on Friday, June 21. We were privileged to have Professor Richard C. Powell from the University of Arizona come and review the current status of solid-state lasers. The good turnout was a testament to the stature Professor Powell has attained within the laser and electro-optic material technology fields. He is one of the true pioneers of solid-state lasers that has published more than 250 peer reviewed journal articles on the subject. His talk clearly displayed his mastery of the subject.

Professor Powell began with a short history of solid-state lasers and he quickly focused in on a specific class of laser, the Raman laser, a topic of his recent research. He introduced the concept of Stimulated Raman Scattering accompanied by Stokes and anti-Stokes frequency shifts and the utility of the Raman effect in producing tunable high-power lasers. This led into a thorough discussion of laser materials, resonator configurations, laser efficiencies, optical power capabilities and modal characteristics. The spectroscopic properties of the materials used in these lasers was presented and the use of these materials in shared-, coupled-, and external-resonator laser systems was described. System design parameters affecting efficiency, beam quality, and temporal pulse width were discussed. He compared the Raman laser with competing Optical Parametric Oscillator (OPO) technology. He pointed out that an important differentiating factor between the two optical sources is that the Raman laser relies on a 3rd order nonlinear effect whereas the OPO relies on a 2nd order nonlinear effect. This leads to a phase matching requirement for the OPO and no phase matching condition for the Raman laser, a clear advantage of the Raman laser.

Interesting applications of the Raman laser were presented and discussed. These included the use of Raman materials in optical amplifiers for long-haul fiber optic communication systems and the use of Raman lasers for atmospheric and marine imaging LIDAR systems. He concluded his talk by introducing the concept of Raman image amplification and its related defense and commercial applications.

Professor Powell fielded many questions from the attentive audience throughout his talk, indicating a high level of interest in this topic. His command of the subject matter and his relaxed lecturing style made it easy for the audience to follow and participate. This talk had something for the novice as well as the expert and the audience was very appreciative. The meeting adjourned at a little after 9 PM.