Solid-state dye laser with photo-induced distributed feedback

This paper describes the action of a solid-state dye laser utilizing a photo-induced distributed feedback (DFB) resonator. We solidified rhodamine B into a dried xerogel monolith using the sol-gel method, and used it as an active laser medium. The pump source was third-harmonic generation (THG) produced by a pulse Nd:YAG laser. We divided the pump beam in two and irradiated the two beams on the active medium. The interference fringes simultaneously form both a spatial periodic modulation of optical gain and a refractive index in the active medium. This periodical structure functions as a DFB resonator. Without an external resonator, we achieved a laser oscillation with a narrowed spectrum. The full width at half maximum (FWHM) of the laser wavelength was approximately 1 nm. We tuned the center wavelength of the laser from 600 nm to 635 nm. In addition, we achieved a second-other DFB laser oscillation with second-harmonic generation (SHG) of a Nd:YAG laser.