High-gain, polarization-preserving, Yb-doped fiber amplifier for low-duty-cycle pulse amplification

Amplified spontaneous emission (ASE) suppression techniques were utilized to fabricate a double-pass, Yb-doped amplifier with the noise properties of a single-pass amplifier. Simulations based on a rate equation model were used to analyze the ASE and the effectiveness of the suppression techniques. These techniques were implemented in an alignment-free, double-pass, Yb-doped fiber amplifier with a 26 dB gain at a wavelength 23 nm off the gain peak and a -48 dB noise floor while amplifying linearly polarized optical pulses with a low-duty cycle.