In situ FBG inscription during fiber laser operation.

We demonstrate the inscription of a 266 nm UV femtosecond pulse-induced fiber Bragg grating (FBG) in an Yb-doped fiber during optical pumping at 976 nm and the initiation of lasing with increasing grating reflectivity. Output spectra show the emission of the pumped fiber changing from the broad-ranged amplified spontaneous emission in the nonlasing case to the narrow-range laser operation due to the enhancement of FBG reflectivity during inscription. The proposed technique enables the direct characterization and control of FBG performance in fiber lasers. After FBG fabrication, we investigate the spectral characteristics of the fiber laser for different laser powers and study the influence of a thermal treatment of the FBG.

[1]  Fabian Stutzki,et al.  Passively stabilized 215-W monolithic CW LMA-fiber laser with innovative transversal mode filter , 2010, LASE.

[2]  Stavros Pissadakis,et al.  An elliptical Talbot interferometer for fiber Bragg grating fabrication , 2005 .

[3]  D N Payne,et al.  Er(3+):Yb(3+)-codoped fiber distributed-feedback laser. , 1994, Optics letters.

[4]  John Canning,et al.  Optical loss mechanisms in femtosecond laser-written point-by-point fibre Bragg gratings. , 2008, Optics express.

[5]  M. Shlyagin,et al.  Type IIA photosensitivity and formation of pores in optical fibers under intense ultraviolet irradiation , 2007 .

[6]  Johannes Kirchhof,et al.  Materials for high-power fiber lasers , 2006 .

[7]  David J. Richardson,et al.  High power fiber lasers: current status and future perspectives [Invited] , 2010 .

[8]  Jens Limpert,et al.  Fiber lasers and amplifiers: an ultrafast performance evolution. , 2010, Applied optics.

[9]  Y Sheng,et al.  Ytterbium fiber laser based on first-order fiber Bragg gratings written with 400 nm femtosecond pulses and a phase-mask. , 2009, Optics express.

[10]  Jens Limpert,et al.  Erbium fiber laser based on intracore femtosecond-written fiber Bragg grating. , 2006, Optics letters.

[11]  J. J. Montiel i Ponsoda,et al.  Refractive index change in ytterbium-doped fibers induced by photodarkening and thermal bleaching. , 2010, Applied optics.

[12]  W H Loh,et al.  Efficient single-frequency fiber lasers with novel photosensitive Er/Yb optical fibers. , 1997, Optics letters.

[13]  L. Norin,et al.  Preventing photodarkening in ytterbium-doped high power fiber lasers; correlation to the UV-transparency of the core glass. , 2008, Optics express.

[14]  Nemanja Jovanovic,et al.  Stable high-power continuous-wave Yb(3+)-doped silica fiber laser utilizing a point-by-point inscribed fiber Bragg grating. , 2007, Optics letters.

[15]  Hartmut Bartelt,et al.  Towards a monolithic fiber laser with deep UV femtosecond-induced fiber Bragg gratings , 2011 .

[16]  Bertrand Poumellec,et al.  Experimental evidence of two types of photorefractive effects occuring during photoinscriptions of Bragg gratings within germanosilicate fibres , 1993 .

[17]  John Canning,et al.  Correlation between photodarkening and index change during 193 nm irradiation of germanosilicate and phosphosilicate fibers , 1997 .

[18]  Hartmut Bartelt,et al.  Femtosecond pulse-induced fiber Bragg gratings for in-core temperature measurement in optically pumped Yb-doped silica fibers , 2012 .