Ultrafast VECSELs with high peak power are of great interest for gigahertz frequency combs, as they provide a high power per comb-line and large comb-tooth spacing. However, the detection and stabilization of the carrier-envelope-offset frequency (f_CEO) using an f-to-2f detection scheme, crucial for most frequency comb applications, requires short pulse durations around 100 fs combined with kilowatt peak power to generate a coherent octave-spanning supercontinuum. We present the detection of the f_CEO beat notes from an ultrafast semiconductor laser. The laser is a SESAM-modelocked VECSEL which generates 231-fs pulses in 100-mW average output power at a repetition rate of 1.75 GHz and a wavelength of 1040 nm. As the performance of the oscillator is not sufficient for direct f_CEO detection the pulses were amplified in an Yb-doped fiber amplifier and subsequently broadened by self-phase modulation in a large mode area fiber. The amplified pulses were compressed to a pulse duration of 85 fs at 2.2 W of average output power and launched into a highly nonlinear photonic crystal fiber. A coherent octave-spanning supercontinuum covering 680 nm to 1360 nm was generated, which supported for the first time f_CEO detection from a femtosecond VECSEL in a standard f-to-2f interferometer.

Date Published: 4 March 2015
PDF: 7 pages
Proc. SPIE 9349, Vertical External Cavity Surface Emitting Lasers (VECSELs) V, 93490F (4 March 2015); doi: 10.1117/12.2078140

Published in SPIE Proceedings Vol. 9349:
Vertical External Cavity Surface Emitting Lasers (VECSELs) V
Mircea Guina, Editor(s)