A passively mode-locked
solid-state
laser is designed to emit a continuous-
wave train (51, 52) of electromagnetic-
radiation pulses, the fundamental repetition rate of the emitted pulses exceeding 1 GHz, without Q-switching instabilities. The
laser includes an optical
resonator (3.1), a
solid-state
laser gain element (2) placed inside the optical
resonator (3.1), a device (1) for exciting said laser
gain element (2) to emit
electromagnetic radiation having the effective
wavelength, and a device (4) for passive
mode locking including a saturable absorber. The laser
gain element (2) is a laser material with a
stimulated emission cross section exceeding 0.8×10−18 cm2 at the effective
wavelength, and is made of Nd:
vanadate. The saturable absorber (4) is preferably a
semiconductor saturable absorber mirror (SESAM) device. Even higher repetition rates are achieved by operating the laser in the
soliton regime. For use in
fiber-optical telecommunication, the laser
wavelength is preferably shifted to 1.5 μm by use of an
optical parametric oscillator. The laser is simple, robust, compact, efficient, and low-cost. It generates a relatively large average power of 100 mW and higher, which is useful for a number of
optical probing and detection applications, in a beam (51, 52) that is substantially a fundamental spatial mode.