High-energy Q-switched Nd:YAG oscillator and amplifier development for large-mode, low-alignment sensitivity applications

Abstract

High pulse energy, low-alignment sensitivity master-oscillator power-amplifier (MOPA) systems enable portable long range laser devices. Comprehensive amplifier modelling is an essential tool in producing efficient, optimised amplfication capable of producing high pulse energies. This paper outlines the development of a large-mode, low-alignment sensitivity neodymium yttrium aluminium garnet (Nd:YAG) (MOPA) system, achieving a total output pulse energy of 265 mJ with an optical efficiency of 18%. A Q-switched diode-pumped Nd:YAG zig-zag oscillator is developed with an output pulse energy of 98 mJ and slope efficiency of 31%. Through the use of an intracavity aperture, the beam quality exhibited an M2 of 4.3 and 4.6 and far field divergence of 1.3 mrad and 1.2 mrad in the horizontal and vertical, respectively. The oscillator output is amplified within a diode-pumped Nd:YAG zig-zag amplifier with a system amplification of 2.8. Comprehensive amplifier modelling based on a Frantz-Nodvik analysis is demonstrated, with the saturation characteristics suggesting a route to further energy enhancement and highlighting the necessity for amplifier modelling in high energy system design.

Red and green dual-wavelength Pr:LiGdF4 laser with a single birefringent filter

“…Continuous-wave (CW) dual-wavelength lasers, which emit in the infrared spectral region with wavelengths separated by a few THz, have been established and applied in THz imaging and spectroscopy [1][2][3][4][5]. At present, CW dual-wavelength lasers for different transitions of Nd 3+ or Yb 3+ have been reported for some crystals [6][7][8][9][10][11][12][13][14][15][16]. However, few researches on dual-wavelength Nd 3+ -doped lasers in the visible spectral region have been reported [17][18][19].…”

Diode-Pumped Laser for Rangefinders Operating over Wide Temperature Range

“…Импульсные твердотельные лазеры ближнего ИК-диапазона применяются в качестве передающей части в системах дистанционного зондирования и исследования атмосферы [1]. Мощные лазеры на основе кристалла Nd:YAG с диодной накачкой с энергией в импульсе более 50 мДж получили широкое использование в импульсных лазерных дальномерах для применения на борту вертолетов или беспилотных летательных аппаратов с дальностью измерений от 20 км [2-4], в активных оптических системах [5], а также в качестве передающей части и задающего генератора в системе генератор-усилитель в аэрозольных лидарах [6,7]. Для указанных применений расходимость излучения после расширяющего телескопа обычно не превышает 0,3-0,5 мрад.…”

Research on collinear double pulse generation method of electro-optical Q-switched Nd:YAG laser

“…Nd:Y 3 A l5 O 12 (Nd: YAG) is one of the most popular solid-state laser gain media due to its high emission cross section, long upper state lifetime, and high thermal conductivity. 21,22) This combination provides it with high-energy storage, low loss, and high efficiency, which is ideal for industrial, medical, military, and scientific applications. 23) In this study, Nd:YAG was chosen as the gain medium for the demonstration experiment of the electro-optical Q-switched double pulse.…”