1 MHz repetition rate single-frequency gain-switched Nd:YAG microchip laser

Abstract

Gain-switched Nd:YAG microchip lasers have produced 1 MHz repetition rate, single-frequency pulses with a pulse width of 32 ns. This is, to our knowledge, the highest repetition rate obtained in a single-frequency gain-switched solid state laser. The laser peak power and pulse width are mainly determined by the peak power of the pumping pulse and independent of the pulse repetition rate. Single-frequency operation is realized by temperature-tuning of the laser wavelength to the peak of the gain profile. Gain-switching at high repetition rates significantly improves the optical efficiency of the device. Time, µs

High power 2 MHz passively Q-switched nanosecond Nd:YVO4/Cr4+:YAG 914 nm laser

“…The main restriction could be attributed to the significant reabsorption loss and the smaller stimulated emission cross section in Nd 3 -doped quasi-three-level lasers. Nd:YVO 4 crystal is a widely used laser medium because of its perfect characteristics, such as high absorption and emission cross section and polarized output [12][13][14]. However, there has not been any report on passively Q-switched Nd:YVO 4 914 nm lasers, which is more apt in high-repetition-rate operation for its unique characteristics.…”

High-power, continuous-wave, Nd:LuVO4 microchip lasers

“…30. 3 From the result of # 1 -# 4, it could be seen that 1.5 mm microchips were better than 1 mm microchips. The maximum laser output power and the optical-optical conversion efficiency of 1.5 mm microchips (# 1, # 2) were higher than those of 1 mm microchips (# 3, # 4).…”

“…By the time now, most reported LD-pumped microchip lasers were based on YAG crystal, Nd 3+ or Yb 3+ doped. Gain-switched Nd:YAG microchip lasers have produced 1 MHz repetition rate, single-frequency pulses with a pulse width of 32 ns [3]. Based on a side-pumped Nd:YAG/Cr:YAG bonded slab, 4.75 W output power and 43.9 kW peak power were achieved with 9 kHz repetition rate and 12 ns pulse width [4].…”

A 37 mJ, 100 Hz, high energy single frequency oscillator*

“…[9][10][11][12][13][14][15][16][17][18] To obtain a single-frequency laser, three problems need to be solved, including single longitudinal mode selection, single transverse mode selection, and energy enhancement. For single longitudinal mode selection, several ways have been developed, such as short cavity configuration, [19][20][21][22][23] microchip lasers, [23,24] non-planar ring oscillator, [25][26][27][28][29][30] traveling-wave cavity, [31][32][33][34][35][36][37][38][39] twisting mode lasers, and inserted multi etalons. [31][32][33][34][35][36][37][38][39][40][41][42] Techniques used for single transverse mode selection include inserted aperture or lens, long cavity, end pump laser, and thermally near unstable resonator.…”