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We demonstrated a compact high-efficiency 100-W-level, narrow-linewidth, quasi-continuous-wave (QCW) diode-side-pumped Nd:YAG laser with a linearly polarized TEM00 mode. Spatial hole-burning elimination and narrow-linewidth laser output were realized by a twisted-mode cavity and an etalon, respectively. The resonator was based on a thermally near-unstable cavity design with dual-rod birefringence compensation convex-convex structure. A 100.4-W linear polarized 1064-nm laser was achieved with a 340-W pump power, corresponding to an optical-to-optical conversion efficiency of 29.5%. The wavelength of the laser was tunable from 1064.22634 to 1064.68071 nm while stably maintaining a beam quality of M2 = 1.22 and a linewidth of ~240 MHz. The laser was operated at a repetition rate of 500 Hz with 160-μs pulse duration. To the best of our knowledge, this represents the highest average-power and the highest brightness for narrow-linewidth QCW microsecond pulse 1064-nm lasers. [ABSTRACT FROM PUBLISHER]

A frequency stabilization approach is introduced for the microsecond pulse sodium beacon laser using an intracavity tilt- and temperature-tuned etalon based on a computer-controlled feedback system connected with a fast high-precision wavelength meter. The frequency stability of the sodium beacon lasers is compared with and without feedback loop controlling. The output wavelength of the laser is locked to the sodium D absorption line (589.159 nm) over 12 h with the feedback loop controlling technology. As a result, the sodium laser guide star is successfully observed by the telescope of National Astronomical Observatories at Xinglong. This approach can also be used for other pulses and continuous-wave lasers for the frequency stabilization. [ABSTRACT FROM AUTHOR]

A high-pulse-energy high-beam-quality tunable Ti:sapphire laser pumped by a frequency-doubled Nd:YAG laser is demonstrated. Using a fused-silica prism as the dispersion element, a tuning range of 740–855 nm is obtained. At an incident pump energy of 774 mJ, the maximum output energy of 104 mJ at 790 nm with a pulse width of 100 μs is achieved at a repetition rate of 5 Hz. To the best of our knowledge, it is the highest pulse energy at 790 nm with pulse width of hundred micro-seconds for an all-solid-state laser. The linewidth of output is 0.5 nm, and the beam quality factor M2 is 1.16. The high-pulse-energy high-beam-quality tunable Ti:sapphire laser in the range of 740–855 nm can be used to establish a more accurate and consistent absolute scale of second-order optical-nonlinear coefficients for KBe2BO3F2 measured in a wider wavelength range and to assess Miller’s rule quantitatively. [ABSTRACT FROM AUTHOR]

We describe the results of our efforts in suppressing spiking of a high power, high beam quality 1319 nm Nd:YAG microsecond-pulse laser with three different intracavity frequency doublers. The 1319 nm laser is generated by a quasi-continuous-wave diode-pumped Nd:YAG ring laser system. One potassium titanyl phosphate (KTP), two KTPs and one lithium triborate (LBO) as frequency doublers are installed in the ring resonator and tested, respectively. At 800 Hz repetition rate, with a pulse width of 100 µs, performances of spiking suppression for each case are observed. The average output power are 23.6 W, 22.7 W and 23.4 W with beam quality factors of M2  =  2.21, 1.28 and 1.25 for one KTP, two KTPs and one LBO, respectively. The corresponding brightness are 270 MW/(cm2·sr), 780 MW/(cm2·sr) and 860 MW/(cm2·sr). With better beam quality, higher brightness, and easier maintainability, the LBO is the best option of the three. A laser rate equation model including the insertion loss of the doubler is applied for theoretical analysis of the output temporal pulse shape and power, and the simulated results agree well with the experimental data. [ABSTRACT FROM AUTHOR]