EventsDr. Alphan Sennaroğlu

Application of graphene and voltage controlled graphene devices in ultrashort laser pulse generation

Nano-structured carbon saturable absorbers (single-walled carbon nanotubes, graphene, and graphene-based super capacitors) can be employed as fast saturable absorbers to initiate femtosecond pulse generation from lasers. The presentation will describe some of our recent experiments, where such devices were employed to generate femtosecond pulses from different tunable solid-state lasers operating in the near to mid-infrared between 800 and 2500 nm. Our experiments show that voltage controlled graphene-based super capacitor structures can be employed as saturable absorbers with adjustable loss and offer a versatile approach to pulse generation over a wide wavelength range. Data showing the nonlinear optical characteristics of these modulators as well as the mode-locked performance of the femtosecond lasers will be presented.

About The Speaker

Alphan Sennaroğlu is a professor in the Departments of Physics and Electrical-Electronics Engineering at Koç University. He is also the Director of Koç University Surface Science and Technology Center (KUYTAM).  He received his BS, MS, and PhD degrees in Electrical Engineering from Cornell University in 1988, 1990, and 1994, respectively. He founded the Koç University Laser Research Laboratory in 1994 and has led its research activities in the areas of infrared solid-state lasers, ultrafast lasers, and spectroscopy. He was a visiting researcher at the Massachusetts Institute of Technology during the 2002-2003 and 2009-2010 academic years. He served as a Program Chair of several international conferences including “Advanced Solid-State Photonics/Lasers Congress” (2010-2016, Optical Society of America) and “Solid-State Lasers and Amplifiers Conference” (2004-2006, SPIE, Photonics Europe). Alphan Sennaroğlu served as the Dean of the College of Sciences at Koç University between 2010 and 2016. He is the recipient of the 2013 TÜBİTAK Science Award, a Fellow of the Optical Society of America, and a Senior Member of IEEE (Institute of Electrical and Electronics Engineers).  He authored the book “Photonics and Laser Engineering: Principles, Devices and Applications” published by McGraw-Hill in 2010.