Generation of 6.5 W, 124 fs linearly polarized pulse using a compact Yb-doped photonic crystal fiber laser

Abstract High-quality, ultrafast fiber lasers have long been favored by both research and industry for many desirable properties. Here, we present an Yb-doped fiber laser system by utilizing a directly spliced photonic crystal fiber (PCF) to amplify a seed source, and 124 fs ultrashort pulses are obtained with an average power of 6.55 W and at a repetition rate of 100.15 MHz. This system efficiently boosts dissipative soliton pulses generated through nonlinear polarization rotation, achieving a maximum output power of 8.37 W, with a corresponding slope efficiency of 55.8%. After compression, a linearly polarized output of 124 fs and 6.55 W is achieved, corresponding to a peak power of 527 kW. To the best of our knowledge, this is the highest linearly polarized output power in 100 fs level from single-stage fiber amplifier based on PCF. The M 2 factors are measured to be about <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mi>M</mml:mi> <mml:mi>x</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> </mml:mrow> </mml:math> = 1.13 and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msubsup> <mml:mi>M</mml:mi> <mml:mi>y</mml:mi> <mml:mn>2</mml:mn> </mml:msubsup> </mml:mrow> </mml:math> = 1.12, respectively. The standard deviation of output power over a 2.5 h period is determined to be 0.72% and no significant wavelength drifts or intensity fluctuations are observed. Furthermore, the laser system has been employed to generate supercontinuum in PCF, confirming the practical capabilities of this laser. These results demonstrate the promising potential of this compact fiber laser system for both research and industrial applications.