Passive Q switching of a solar-pumped Nd:YAG laser

Abstract

Passive Q switching is a preferable choice for switching the Q factor of a solar-pumped laser because it requires neither a driver nor an electrical power supply. The superior thermal characteristics and durability of Cr(4+):YAG single crystals as passive Q switches for lamp and diode-pumped high-power lasers has been demonstrated. Here we report on an average power of 37 W and a switching efficiency of 80% obtained by use of a solar-pumped Nd:YAG laser Q switched by a Cr(4+):YAG saturable absorber. Concentration of the pumping solar energy on the laser crystal was obtained with a three-stage concentrator, composed of 12 heliostats, a three-dimensional compound parabolic concentrator (CPC) and a two-dimensional CPC. The water-cooled passive Q switch also served as the laser rear mirror. Repetition rates of as much as 50 kHz, at pulse durations between 190 and 310 ns (FWHM) were achieved. From the experimental results, the saturated single-pass power absorption of the Cr(4+):YAG device was estimated as 3 ? 1%.

Solar pumping of solid state lasers for space mission: a novel approach

“…:YAG crystal saturable absorber [9,10]. A similar approach in fiber configuration will allow the realization of an all fiber pulsed SPL, eliminating the use of optical discrete components and thus resulting in higher laser reliability.…”

Solar pumped Nd:YAG laser efficiency enhancement using Cr:LiCAF frequency down-shifter

“…A number of researches on solar pumped laser have been conducted since the advent of laser itself [1][2][3][4][5][6][7][8][9][10][11]. However, the maximum conversion efficiency was in the range of few percents and not enough for wide spreading of solar-pumped lasers commercially.…”

Enhanced Sunlight Excited 1‐μm Emission in Cr3+–Yb3+ Codoped Transparent Glass‐Ceramics Containing Y3Al5O12 Nanocrystals

“…In 1963, a SPL based on Dy 2+ : CaF 2 crystal was first reported by Kiss et al . Since then, SPLs have been attained in various hosts, and most focus on Nd 3+ single‐doped or Cr 3 + ‐Nd 3+ codoped crystals . In 1997, a solar pumped fiber laser (SPFL) has been proposed .…”