The Q-switched Cr, Nd:YAG laser generates intense, single-frequency laser pulses in a transform-limited spectral linewidth-pulse duration product. The pulse energy is on the order of millijoules and can be scaled up with increasing volume. The typical pulse duration is on the order of nanoseconds.
The laser device consists of a single-crystal Cr, Nd:YAG crystal in which chromium ions act as the saturable absorber for the neodymium laser emission. Mirrors are end-surface coated. The laser material performs all the functions of the conventional laser cavities, such as light modulation, frequency selection, transverse mode control, and polarization selection. This results in a self-contained laser with no moving parts. Varying the material composition and physical dimension can control the pulse duration, of the order of several nanoseconds. The self-induced grating inside the gain medium ensures single-frequency operation.