GB1418299A - Apparatus for stimulated emission of coherent continuously tunable raman radiation - Google Patents

Abstract

1418299 Lasers CARL ZEISS-STIFTUNG [trading as CARL ZEISS] 11 Dec 1972 [13 Dec 1971] 57125/72 Heading H1C In a stimulated Raman effect system in which a Raman medium such as H 2 is contained between dichroic resonator mirrors and is excited by an external laser, the frequency of the stokes and anti-stokes output radiation produced by scattering may be selectively varied over a range extending from the far infra-red to the near ultra-violet by the combination of a tunable dye excitation laser and a controlled variable pressure applied to the Raman medium. The dye laser, Fig. 1, comprises an active medium 2 of fluorescein, rhodamin 6G or bresyl Violet which is pumped by a flash lamp 1, the laser output being focused by a lens 5 into a Raman cell 10 formed with windows 4, 5. A resonator formed by coated dichroic mirrors 6, 7 is contained within the cell, mirror 6 transmitting the excitation beam from the laser and mirror 7 being partially transmissive of the Raman scattered radiation. In a modification Fig. 2, the resonator mirrors 6, 7 are located outside the Raman cell which is side excited through an additional window 11. A further arrangement, Fig. 3, uses a laser with a plurality of flash lamps 17, the output of the laser active medium 16 being tuned by a device 22 and applied to a Raman cell 20 through a cylindrical lens 19. A cylindrical mirror 18 lines the inner wall of the cell which is provided with resonator mirrors (not shown) along its optical axis 21.