Abstract: A solid-state laser oscillator has a semiconductor laser for biasing a solid-state laser to a threshold value or more and a semiconductor laser for pulse-pumping the solid-state laser. A pulse pump light having a pulse width which is equal to a cycle of relaxation oscillation or more is fed to the solid-state laser through the semiconductor laser for pulse pump thereby to suppress remarkably a relaxation oscillation.

Abstract: A printing device employs a semiconductor laser source for producing a laser beam, and a semiconductor-laser-pumped solid-state laser. The solid-state laser includes an optical resonator, such as a nonlinear optical element for effecting wavelength conversion, and a solid-state laser material disposed therein. The solid-state laser material is optically pumped by the laser beam from the semiconductor laser source and produces a laser beam to be applied onto a photosensitive sheet of paper. Responsive to print data, the intensity of the laser beam from the semiconductor laser source is varied between a first intensity level and a second intensity level. The photosensitive sheet of paper is insensitive to the laser beam when the laser beam from the semiconductor laser source is at the first intensity level, whereas it is sensitive to the laser beam when the laser beam from the semiconductor laser source is at the second intensity level.