Abstract
We experimentally show that a voltage-controlled graphene-gold supercapacitor saturable absorber (VCG-gold-SA) can be operated as a fast saturable absorber with adjustable linear absorption at wavelengths as low as 795 nm. This was made possible by the use of a novel supercapacitor architecture, consisting of a high-dielectric electrolyte sandwiched between a graphene and a gold electrode. The high-dielectric electrolyte allowed continuous, reversible adjustment of the Fermi level and, hence, the optical loss of the VCG-gold-SA up to the visible wavelengths at low bias voltages of the order of a few volts (0–2 V). The fast saturable absorber action of the VCG-gold-SA and the bias-dependent reduction of its loss were successfully demonstrated inside a femtosecond :sapphire laser operating near 800 nm. Dispersion compensation was employed by using dispersion control mirrors and a prism pair. At a bias voltage of 1.2 V, the laser operated with improved power performance in comparison with that at zero bias, and the VCG-gold-SA initiated the generation of nearly transform-limited pulses as short as 48 fs at a pulse repetition rate of 131.7 MHz near 830 nm. To the best of our knowledge, this represents the shortest wavelength where a VCG-gold-SA has been employed as a mode locker with adjustable loss.
© 2017 Optical Society of America
Full Article | PDF ArticleMore Like This
Isinsu Baylam, Osman Balci, Nurbek Kakenov, Coskun Kocabas, and Alphan Sennaroglu
Opt. Lett. 41(5) 910-913 (2016)
I. Baylam, M. N. Cizmeciyan, S. Ozharar, E. O. Polat, C. Kocabas, and A. Sennaroglu
Opt. Lett. 39(17) 5180-5183 (2014)
Yicheng Wang, Weidong Chen, Mark Mero, Lizhen Zhang, Haifeng Lin, Zhoubin Lin, Ge Zhang, Fabian Rotermund, Young Jun Cho, Pavel Loiko, Xavier Mateos, Uwe Griebner, and Valentin Petrov
Opt. Lett. 42(16) 3076-3079 (2017)