RESUMEN
A distributed-feedback (DFB) dye laser that is pumped by a standing Bessel-beam wave is constructed. Because of the long line focus of the Bessel beam, the laser medium is pumped in only a very thin filament (a few micrometers) along the optical axis. At the same time, longitudinal-mode selection is achieved because of the DFB effect. It is demonstrated that when the effective wavelength of the Bessel pump beam is varied, the Bragg wavelength for DFB is altered, and as a result the output wavelength can be tuned.
RESUMEN
We report on a novel pumping scheme for stimulated Raman scattering (SRS) that uses a Bessel beam. We have used this scheme for SRS from molecular vibrations in acetone and from a polariton mode in a LiIO(3) crystal. A nearly diffraction-limited Stokes beam was observed along the cone axis of the Bessel beam. The generation mechanism of the Stokes beam is identified as being due to noncollinear scattering of the component plane waves that constitute the Bessel beam. Frequency tuning of SRS from polaritons in LiIO(3) by variation of the Bessel beam cone angle is demonstrated.