GB1132299A - Laser system - Google Patents

Abstract

1,132,299. Lasers. NIHON DENSHI K.K. 20 Oct., 1967 [26 Oct., 1966], No. 47943/67. Heading H1C. The output of a laser generator 1, Fig. 1, is split by a beam splitter 6-10 into a plurality of beams 11-15 each of which is amplified by a respective laser amplifier 16-20, the amplifier outputs being focused at a point 22 by a lens 21. The lasers may comprise ruby rods 2, 16a, 17a, 18a, 19a and 20a which are pumped by helical lamps 3, 16b, 17b, 18b, 19b and 20b, the laser generator 1 being Q-switched and having a resonator formed by a fixed partiallyreflecting mirror 5 and a rotating prism or mirror 4. The lamps are energized from a power supply 23 in synchronism with the rotating mirror 4, while the beam splitter comprises partially-transmitting mirrors 6-9 and a fullyreflective mirror 10. In a modification, Fig. 2, the duration of a focused output pulse at point 22 is reduced by equalizing the path lengths of the split beams. As shown, the beam splitter comprises partially transmitting mirrors 34, 41 and fully-reflective mirrors 36, 45, each of the split beams 35, 47, 48 passing through a variable optical delay unit 37, 44, 46 which are adjusted to equalize the path lengths. Included in the paths of the split beams are polarizers 38, 49, 50 and laser amplifiers 39, 51, 52, each amplifier comprising a ruby rod having its output face inclined at the Brewster angle. The amplifiers are cylindrically arranged and have individual lenses 40, 53, 54 for focusing the outputs at a common point 55. A further laser amplifier 33 is provided between the Q-switched laser generator 30 and the beam splitter. Gas lasers may be used as an alternative.