Tm³⁺-doped fiber master oscillator power amplifier with broad tunability in pulse duration using an acousto-optic external modulator

ABSTRACT

We demonstrate a pulse-duration tunable Tm³⁺-doped pulsed all-fiber master oscillator power amplifier (MOPA) operating at a central wavelength of 1908 nm. By using acousto-optic(AO) external modulation, the amplified laser pulse shows a tuning range having pulse durations from 66.5 ns to 8.0 μs and a repetition rate of 100 kHz-2 MHz. The laser achieved a maximum average power of 28.1 W and a corresponding energy of 28.1 μJ at 1MHz with a 3 dB linewidth of 0.63 nm and a beam quality factor of M_x²=1.25 and M_y²=1.32. The ASE suppression ratio is 50 dB and the corresponding total amplifier gain is 27.5 dB. To the best of our knowledge, it is the highest average output power and slope efficiency (∼51.0%) achieved using AO external modulation in a Tm³⁺-doped pulsed fiber amplifier.

KEYWORDS:

• Tm³⁺-doped pulsed MOPA
• acousto-optic external modulation
• widely tunable pulse duration
• high slope efficiency

ORCID

G. Y. Jin http://orcid.org/0000-0002-0937-7248

Additional information

Funding

This work was supported in part by the Science and technology development project of Jilin Province under Grant 20180201033GX; the Science and Technology Development Project of Jilin Province under Grant 20190302125GX; Education Department of Jilin Province under Grant JJKH20181102KJ.