Passively Q-switched lasers

Passively Q-switched, diode pumped, all solid-state lasers are an elegant, yet simple, means to generate single-frequency laser pulses in the nanosecond and sub-nanosecond regions. The majority of the work on these systems has been in the 1-μm region, but recent developments at eye-safe and mid-infrared wavelengths of both diode-pumped lasers and solid-state saturable absorbers will probably lead to practical, passively Q-switched lasers at longer wavelengths. However, longer wavelength material properties are expected to only allow the generation of longer duration pulses. In the 1-μm region, near-term advances are anticipated in the development of higher average power systems operating at multikilohertz pulse rates, with pulse energies exceeding 1 mJ and corresponding improvements at second, third, fourth, and even fifth harmonic wavelengths.