Photosensitive Yb-Doped Germanophosphosilicate Artificial Rayleigh Fibers as a Base of Random Lasers

Abstract

Asingle-mode Yb-doped germanophosphosilicate fiber with ultra-low optical losses (less than 2 dB/km) was fabricated by means of the MCVD method utilizing an all-gas-phase deposition technique developed “in house”. The absorption and luminescent spectral properties of the fiber were thoroughly studied. The photosensitivity of the pristine (non-hydrogenated) fiber to 248 nm-laser radiation was confirmed by means of fiber Bragg grating (FBG) inscription directly during the drawing process. The random single-frequency lasing at the 1060-nm-wavelength obtained in the 21-m-long fiber with an array of weak FBG was reported. The developed laser slope efficiency in the backward-pumping scheme was measured as high as 32%.

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

“…This behavior and the oscillation frequency value, however, are typical for Er-doped fiber lasers and it was It was also found that the studied laser operated strictly in a continuous-wave (CW) mode, without any self-pulsing (such as a Q-switch). This result is in good agreement with our previous works [19][20][21][22]25]. The CW laser operation can be explained by the contribution of the dynamic grating formation [19,20].…”

“…Thus, provided that the operating frequency range is within the reflection spectrum of the gratings, OFs with an FBG array are a good alternative to traditional Rayleigh fibers and, therefore, called "artificial Rayleigh fibers". In particular, they can be effectively used in such applications as coherent reflectometry [15,16] and random lasers [17][18][19][20][21][22][23][24][25][26].…”