Multiple mode laser

The present invention relates to lasers and especially to a laser having multiple pulse duration and pulse rate modes of operation. A laser apparatus is described having multiple modes of operation using intracavity optical switching within a laser resonator. The laser resonator has a solid state gain medium and one or more optical switches located between a pair of end reflectors. The pump for the gain medium has controlled duration to allow varying the pumping energy and pulse repetition rate. The laser has a Q-switched mode for generating energy from the laser resonator at a fixed level of outcoupling when the laser pump is operated to produce a range of predetermined pulse, rates and durations. The laser also has a cavity dumped mode of operation in which the laser pump is operated to produce a second range of predetermined higher pulse repetition rates and shorter pulse durations so that the pulse energy, rate and duration are selected by first Q-switching with essentially no outcoupling and then rapidly cavity dumping all the optical energy in the resonator. Intracavity optical switching of the laser resonator is used to achieve the two distinct modes of operation, the first being conventional Q-switched operation with pulse width equivalent to several cavity round trip times and the second being Q-switched cavity, dumped operation with pulse width equivalent to about one cavity round trip time. Use of this apparatus with external frequency shifting optics is also described.