“Ultimate Efficiency Lasers: A design method for CW Lasers Using Distributed Feedback”

Dr. Kuthan Yelen

Optoelectronics Research Centre (ORC), University of Southampton, U.K. 

A novel continuous-wave laser design method is presented, which, for a given pumping scheme and active medium, provides a generalised distributed feedback cavity with the maximum possible efficiency. Taking into account the local pump power, the method relies on the calculation of the optimum intra-cavity signal distribution that results at maximum pump-to-signal conversion at every point along the cavity.  Using this information, the method calculates the required grating strength distribution that results in the desired optimum signal, pump and gain distribution.  Such a cavity is optimally saturated along the entire length.  Experimental verification is also presented by applying the method in an erbium-ytterbium co-doped fibre.

Basic concepts of gratings and distributed feedback lasers are introduced. Modelling and characterisation of Er/Yb coped media and simulation of in-fibre devices such as gratings and amplifiers are also briefly discussed.

Kuthan Yelen was born in Edirne, Turkey on June 27^th, 1977. He received the B.Sc. degree in electrical and electronics engineering from the Middle East Technical University (METU) of Ankara, Turkey in 1999 and received the M.Sc. degree in optical fiber communications from the Department of the Electronics and Computer Science, University of Southampton, United Kingdom in 2001, followed by the Ph. D. degree in 2004 at the Optoelectronics Research Centre (ORC) of the same university, where he developed the design method for ultimate efficiency in linear cavity CW lasers using distributed-feedback. Mr. Yelen was the recipient of scholarships from the National Education Foundation (MEV) of Turkey between 1995 and 1999, and from Turkish Education Foundation (TEV) between 1999 and 2000. He was a Chevening Scholar of the British Council during the same period. Between 2001-2004 Mr. Yelen has received the research scholarship from the University of Southampton and the Overseas Research Students Award (ORS) from the Committee of Vice-Chancellors and Principals of the United Kingdom (CVCP). He acted as the senior scientist at Southampton Photonics (SPI) Inc. for the design of high power amplifiers in novel fibers.

    His research interests include laser theory and technology, optoelectronic device simulation, design and characterization, grating applications, rare-earth media and computational photonics.

March 15, 2005, 15:40, L045