Injection mode-locked guide star laser concept and design verification experiments

Fiber-solid, hybrid, single-frequency laser (100 W) with a 100 MHz repetition rate and 1 ns pulse width from a spherical aberration compensated four-stage Nd:YVO4 amplifier

“…For example, this kind of laser can be used for laser guide stars in ground-based astronomy research [1][2][3]. The lasers used in these types of research emit 589 nm yellow light, which can be achieved by sum frequency generation (SFG) of 1064 nm lasers and 1319 nm lasers [4,5].…”

“…They excite sodium fluorescence in the ionosphere to create artificial guide stars. The lasers used to create artificial guide stars should have characteristics such as high output power (more than 25 W for a 589 nm laser), excellent beam quality (less than 1.3 times the diffraction limit), single-frequency capabilities (linewidth less than 3 GHz), and a stabilized wavelength (frequency stability less than 50 MHz) [3,6,7]. Higher powers of 50 W for a 589 nm laser are preferable for guide star systems [8,9], which requires that the power of the 1064 nm laser reaches the one hundred watts level.…”

“…The pulse width of the laser is ∼0.3 ns, and the linewidth is 2.1 GHz. An injection mode-locking laser has also been reported as a promising approach for advanced guide star lasers [3]. The laser produces a macromicro pulse-burst output.…”

“…Third, the repetition rate and pulse width of the output pulses can be easily tuned as well. The pulse series can also be modulated as macro-micro pulses, which are widely used in guide star systems [1,3]. Su et al [11] reported an all-fiber 1064 nm laser that has over 100 W output with about a 8 ns pulse duration and a 20 MHz repetition rate.…”

Fast rise time, long pulse width, kilohertz repetition rate Q-switch driver

“…Injection-mode-locked Q-switched lasers for sodium guide star applications, however, require drivers that have both a fast rise time and a long pulse duration, 7 and a 1 kHz repetition frequency. To our knowledge, circuits for such drivers have not been published.…”