25  W single-frequency, low noise fiber MOPA at 1120  nm

Abstract

This Letter reports on the development of a 25 W single-frequency, all-fiber master oscillator power amplifier (MOPA) operating at 1120 nm. By heating the gain fiber at 75°C, an output power of 25.3 W is achieved with an optical-to-optical efficiency of 53.5%. The output shows no sign of stimulated Brillouin scattering and the signal to amplified spontaneous emission ratio is close to 40 dB. A M value of 1.15 and a polarization extinction ratio of 17 dB are measured. The relative intensity noise of the output is also characterized, reaching -155 dBc/Hz at 10 MHz at the maximum output power. The study of the noise dynamics highlights, for the first time to the best of our knowledge, an unpredicted behavior due to the strong backward amplified spontaneous emission.

Ultra-low intensity noise, all fiber 365 W linearly polarized single frequency laser at 1064 nm

“…functional quantum calculators [4]), the need for single frequency (SF) high-power fiber lasers has been increasing over the last decade. The ability to maintain an excellent modal quality, the wide tuning range in the Ytterbium (Yb) band [5][6][7][8], the linear polarization and the optical low-noise operation is driving this technology as an excellent replacement for more established high-power bulk systems in the 1 µm region.…”

Low-noise single-frequency 50 W fiber laser operating at 1013 nm

“…An excess of noise at high frequency can also be due to SBS [6,17]. However, here the noise floor does not rise with output power and remains at the same level as the pre-amplifier.…”

“…Despite their remarkable performances in the 1020-1090 nm region, high power, low-noise MOPAs operating outside of this conventional band remain scarce. For L-band (>1100 nm), the weak emission cross-section can be balanced with long fibers, but SBS then quickly becomes the limiting factor [6]. For S-band (<1020 nm), the main issue is the strong signal re-absorption.…”

10 W low-noise green laser generation by the single-pass frequency doubling of a single-frequency fiber amplifier

“…The increased noise from the fiber amplifier is due to the electrical supplies , acoustic disturbance, and power fluctuation of the diode pump (up to 100 kHz) [30]. The shot noise and amplified spontaneous emission noise determine the noise above 100 kHz.…”