2-kW-level superfluorescent fiber source with flexible wavelength and linewidth tunable characteristics

Abstract

Superfluorescent fiber source (SFS) with tunable optical spectrum has shown great application potential in sensing, imaging and spectral combination. Here we demonstrate for the first time, a 2-kilowatt-level wavelength and linewidth tunable SFS.Based on a flexible filtered SFS seed and three stages of fiber amplifiers, the output power can be scaled from milliwatt level to about 2 kW, with a wavelength tuning range of 1068-1092 nm and a linewidth tuning range of 2.5-9.7 nm. Moreover, a numerical simulation is conducted based on the generalized nonlinear Schrödinger equation, and the results reveal that the wavelength tuning range is limited by the decrease of seed power and the growth of amplified spontaneous emission, while the linewidth tuning range is determined by the gain competition and nonlinear Kerr effects. The developed wavelength and linewidth tunable SFS may be applied to scientific research and industrial processing.

Functional Fibers and Functional Fiber-Based Components for High-Power Lasers

“…In recent years, tunable optical filters (TOFs) operating in low-power regimes (typical power capabilities of several milliwatts or watts) have been proposed to enable high-power laser output [432][433][434][435][436][437][438][439][440][441]. Commercial TOFs with different central wavelengths and filtering bandwidths are adopted to modulate the intracavity feedback or the front stage of fiber amplifier (namely, the seed laser).…”

“…A 120-W SFS amplifier was constructed successfully, whose operating wavelength could be tuned from 1050 to 1075 nm continuously with a linewidth tunability from 0.4 to 15.2 nm [440]. Recently, the maximum output power was further increased to 2010 W, in which the tunable linewidth range covers 2.5-9.7 nm [441], as schematically shown in Fig. 12b.…”

“…Photonic lanterns were initially employed as non-mode selective scenes such as astronomical applications [444] or mode multiplexers [445,446]. Until 2016, related studies began to develop the ability of active feedback to stabilize the fundamental mode output from a multimode fiber by appropriately launching the correct superposition of input modes in both phase and amplitude [443,[441][442][443][444][445][446][447][448][449][450]. At first, mode controllable output from a two-mode fiber amplifier that reaches several watts was realized based on the selective mode amplification in a photonic lantern [447].…”

Experimental investigation of the stimulated Raman scattering effect in high-power nanosecond superfluorescent fiber source

“…Thus, the nanosecond fiber seed generated by externally modulated SFS can resolve the temporal instability issues associated with the resonant cavity structure-based nanosecond fiber seed. However, demonstrations of high-power SFS amplifiers have predominantly focused on continuous-wave SFSs [ 22 – 26 ] , with reports on pulsed SFS amplifiers featuring high average power and large pulse energy being relatively scarce. Park et al .…”

“…Thus, the nanosecond fiber seed generated by externally modulated SFS can resolve the temporal instability issues associated with the resonant cavity structure-based nanosecond fiber seed. However, demonstrations of high-power SFS amplifiers have predominantly focused on continuous-wave SFSs [22][23][24][25][26] , with reports on pulsed SFS amplifiers featuring high average power and large pulse energy being relatively scarce. Park et al [19] reported a narrowband nanosecond superfluorescent fiber source (ns-SFS) with an average power of 41.5 W, pulse energy of about 0.4 mJ and pulse width of 26.4 ns, while pulsed SFS amplifiers delivering average power at the hundred-watt level and pulse energy at the approximately 10 mJ level have yet to be reported.…”