FIXED-WAVELENGTH OPERATION OF A COPPER-LASER-PUMPED DYE-LASER INJECTION SEEDED BY LOW-POWER HE-NE LASERS

The design and operating characteristics of a dye laser pumped by a 3- W copper-vapor laser (CVL) and injection seeded by low-power (1-5 mW) He-Ne lasers at 633 nm are reported. An extremely simple optical arran gement is used wherein the output mirror of the He-Ne laser and a thir d mirror form the dye laser cavity. Laser efficiency in fixed-waveleng th operation has been investigated for variable CVL pump power, He-Ne injection power and polarization and cavity output coupling for a stan dard Rhodamine 590/Rhodamine 640 dye solution. Over 90% of free-runnin g (unseeded) laser power is obtained in fixed-wavelength (seeded) oper ation at low CVL pump powers (less than or equal to 1 W), dropping to approximately 60% at 3-W pump power. Maximum CVL pump to dye laser opt ical conversion efficiency in narrow-band, fixed-wavelength operation at 633 nm was 12%.