A high-power high-efficiency Nd:YAG slab laser with lamp pumping is developed by use of a novel diffusive-closed coupled lamp pump cavity. In cw-mode operation, 1.45 kW of output power is obtained with a slope efficiency of 5.0%. In pulsed-mode operation (50 pulses/s, 25% pulse duty), 1.4 kW of output power is obtained with a slope efficiency of 4.3%. The output power per unit volume is 45 W/cm(3). To our knowledge, these output powers and the power per unit volume are the highest obtained for the single-head Nd:YAG slab laser with lamp pumping.
With the emergence of large-mode-area fiber and cladding pump technique, output power of rare-earth doped fiber lasers are grown rapidly in recent years. However, "bulk solid-state-laser" is still a choice of geometry in high-pulse-energy regime'. Scaling of pulse energy with a fiber-based system is limited mainly due to damage threshold, nonlinear effect, and energy dissipation induced by ASE (Amplified Spontaneous Emission). To overcome these issues, various systems have been reported so far. The approaches by fiber-based amplifier scheme could be divided into two groups from the viewpoint of seed pulse: (1) pulsed laser diode or pulsed-laser-diode-pumped fiber laser, (2) Q-switched solid-state laser2. In first approach, complex multi-stage amplifier is indispensable because of relatively weak laser diode seed pulse. We considered the second approach is better adapted to our target, industrial, high-energy, and high-repetition-rate material processing application. Since, established Q-switched solid-state-laser technique enables flexible and reliable pulse waveform and repetition-frequency control, a monolithic fiber laser system allows highly-efficient amplification.The experimental apparatus was consisted of an in-house Q-switched Nd:YAG rod laser oscillator and a Yb-doped fiber amplifier (Fig. 1). As a result, we obtained an average output power of 48 W with a typical clean Q-switched pulse waveform at a repetition rate of 2 kHz. The corresponding pulse duration time was 150 ns (FWHM). This is, to our knowledge, the highest pulse energy obtained with a solid-state-laser oscillator and a fiber-based amplifier scheme.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.