Modeling and measurement of ytterbium fiber laser generation spectrum

A generation spectrum of a fiber laser becomes broader with increasing generation power. The spectra are rather narrow at low power and become comparable with fiber Bragg gratings (FBG) width at high power. It has been shown that the spectral broadening of a fiber laser can be described analytically if the generation spectrum is much narrower than the FBG width. The developed theory has been compared with experiment. Double clad Yb-doped fiber laser of up to 10 W output power is used in the experiment. Scanning Fabry-Perot interferometer with resolution down to 1.2 pm is applied for accurate spectral measurements. At power level less then 1 W a self-sustained pulsation regime accompanied by a narrow-line self-sweeping is observed. At higher power a quasi-CW generation regime with multiple longitudinal modes is established. Investigation of the regime shows linear increase of the generation width with generation power growth. Slope of the dependence has excellent agreement with the theory, but an additive quantity should be added to describe an absolute value that makes significant contribution at low powers. It has been shown that at low powers a spatial hole burning has to be considered. Theoretical model describing the hole burning effect for multimode cw generation is also developed. After inclusion of the hole burning effect the model starts to agree quantitatively with the linewidth measurements both at low and high powers.

[1]  Sylvain Bordais,et al.  A broadband ytterbium-doped tunable fiber laser for 3He optical pumping at 1083 nm , 2003 .

[2]  Martin Scheid,et al.  4W continuous-wave narrow-linewidth tunable solid-state laser source at 546nm by externally frequency doubling a ytterbium-doped single-mode fiber laser system. , 2007, Optics express.

[3]  Pascal Besnard,et al.  Double-clad 10-W Yb3+-doped fiber master oscillator power fiber amplifier for He3+ optical pumping. , 2004, Applied optics.

[4]  Ekaterina A. Zlobina,et al.  Continuous-wave parametric oscillation in polarisation-maintaining optical fibre , 2011 .

[5]  I͡Akov Izrailevich Khanin,et al.  Fundamentals of Laser Dynamics , 2005 .

[6]  A. E. Ismagulov,et al.  Spectral broadening in Raman fiber lasers. , 2006, Optics letters.

[7]  Sergey A. Babin,et al.  Four-wave-mixing-induced turbulent spectral broadening in a long Raman fiber laser , 2007 .

[8]  Ammar Hideur,et al.  Dynamics and stabilization of a high power side-pumped Yb- doped double-clad fiber laser , 2000 .

[9]  Sergey A. Babin,et al.  Spectral broadening of incoherent nanosecond pulses in a fiber amplifier , 2012 .

[10]  A E Bednyakova,et al.  Modeling of CW Yb-doped fiber lasers with highly nonlinear cavity dynamics. , 2011, Optics express.

[11]  J. Manassah,et al.  Self-phase modulation of incoherent light revisited. , 1991, Optics letters.

[12]  V. A. Akulov,et al.  Frequency tuning and doubling in Yb-doped fiber lasers , 2007 .

[13]  M. Kavehrad,et al.  Analytical model for rare-earth-doped fiber amplifiers and lasers , 1994 .

[14]  J. A. Alvarez-Chavez,et al.  Wide wavelength-tuning of a double-clad Yb3+-doped fiber laser based on a fiber Bragg grating array , 2007 .

[15]  Andrei S Kurkov,et al.  Moderate-power cw fibre lasers , 2004 .

[16]  I. Kelson,et al.  Strongly pumped fiber lasers , 1998 .

[17]  S. Babin,et al.  Broad-range self-sweeping of a narrow-line self-pulsing Yb-doped fiber laser. , 2011, Optics express.

[18]  Michel Piché,et al.  Linewidth of high-power fiber lasers , 2009, Photonics North.