High Efficient Random Laser with Cavity Based on the Erbium-Doped Germanophosphosilicate Artificial Rayleigh Fiber

The Erbium “random” laser, based on the artificial Rayleigh fiber, has been comparatively studied in detail under two different pump conditions: 974.5 and 1485 nm pumping wavelengths. 7-m-long fiber was used as a laser cavity, it formed by ultraviolet (UV) inscription of uniform array weakly reflective Bragg grating (FBG) during drawing process. UV photosensitivity Erbium-doped originated from specially developed (germanophosphosilicate) core glass composition. emission spectrum fabricated had single narrow peak at 1548 wavelength. It clearly revealed that extension cavity separate wavelength-matched 90%-reflective FBG resulted significant efficiency growth. highest slope 33% output power 80 mW were reached FBG-modified 974.5-nm-wavelength pumping. continuous-wave operation mode this confirmed. linewidth value measured delayed self-heterodyne technique about 550 Hz.