Abstract: A single frequency solid state laser has been designed for generation of a high power Q-switch pulse followed by a quasi-CW low power tail by properly controlling the laser resonator transmission via an intracavity Q-switch. The generation of a stable single frequency pulse is accomplished by a primary feedback control system containing a central timing and prelase control unit. Generation and smoothing control of a quasi-CW pulse tail is accomplished through a secondary feedback control system.

Abstract: A cavity which is resonant at a laser pumping frequency is defined by a reflective surface (92) and a mirror (110). A Raman medium (106) is contained within the cavity, as is a laser (90). A Q-switch (94), when not spoiling the Q of the cavity, allows photon density to increase within the cavity. When the Raman threshold of the Raman medium is exceeded, the Raman medium absorbs and then radiates photons. The radiated photons are at longer wavelength than the laser photons, and also occur in very short (less than ten nanoseconds) pulses. The radiated photons are reflected by a mirror (101) and exit the cavity through one of the reflectors defining the cavity (mirror 110). The invention shifts the wavelength and shortens the pulse duration of pulses produced by the laser (90).

Abstract: A lasing medium (3) and a Raman medium (20) share a common optical cavity. The lasing medium (3) projects laser light into the Raman medium (20) and, when a threshold intensity within the Raman medium is reached, the Raman medium absorbs the laser light and re-radiates coherent light at a shifted frequency. Optical elements within the system provide an optical cavity for the lasing medium and a second cavity for the Raman medium.