Femtosecond Nd:Glass Lasers Pumped by Single-Mode Laser Diodes and Mode Locked With Carbon Nanotube or Semiconductor Saturable Absorber Mirrors

Abstract

In this paper, single-mode 200-mW laser diodes have been demonstrated to be very effective pump devices for low-power Nd:glass lasers, yielding the remarkable continuous wave (cw) slope efficiency of 46.5% for silicate and 58.2% for phosphate glasses, respectively. Femtosecond operation has been investigated with both semiconductor saturable absorber mirrors (SESAMs) and a single-walled carbon nanotube SAM (SWCNT-SAM). Furthermore, a detailed comparison of the mode-locking performance with Nd: phosphate and Nd: silicate, employing either one of the SA devices is presented. Although not fully optimized for this particular application yet, SWCNT-SAs yielded sub-100-fs pulses for the first time in Nd: glass. With SESAM mode locking and a single-prism resonator for dispersion compensation, pulse duration as short as 92 fs has been measured, whereas shorter pulses down to 80 fs have been obtained with a two-prism resonator. Tuning range as broad as 30 nm and output power up to 55 mW have also been achieved, confirming the effectiveness of the proposed laser architecture