<p>In a solid laser, a laser medium is efficiently cooled to obtain a great output by increasing power to the laser medium and to reduce a heat lens effect occurring in the laser medium. In a solid laser including a laser medium and an excitation lamp for applying excitation beam to the laser medium, a cooling system for the laser medium and a cooling system for the excitation lamp are independently operated with separate water feed pumps. A cooling pipe for enclosing the excitation lamp and the laser medium is made of quartz glass doped with cerium, which does not pass light having a wavelength of below 320 nm. <IMAGE></p>
