Broadband and top-flat mid-infrared supercontinuum generation with 3.52 W time-averaged power in a ZBLAN fiber directly pumped by a 2-µm mode-locked fiber laser and amplifier

Abstract

Supercontinuum generation from 1.87 to 4.03 µm in a ZBLAN fiber is reported. A home-made passively mode-locked thulium-doped fiber laser and amplifier, providing 21.4-ps pulses at 81 MHz is used as a pump. The continuum output power is 3.52 W, of which 1.45 and 0.88 W corresponds to wavelengths longer than 3 and 3.5 µm, respectively. A spectrum flatness of 2 dB over a bandwidth of 1710 nm, from 2.02 to 3.73 µm, is also reported. This represents, to our knowledge, the best power conversion in the mid-infrared region and the best spectral flatness for high power supercontinuum generation in ZBLAN fibers directly pumped by 2-µm CW mode-locked fiber lasers and amplifiers.

Long-term stable supercontinuum generation and watt-level transmission in liquid-core optical fibers

“…Therefore, our study suggests that LCFs infiltrated with inorganic solvents enable handling of even higher amounts of average power, as long as certain pulse energy is not exceeded. This could yield a performance comparable to soft glass fibers, where MIR SCG was demonstrated at multi-Watt level for ZBLAN fibers [27,28]. However, only chalcogenide glasses offer full access to the fingerprint spectral region beyond 6 µm [29] at comparably low damage thresholds.…”

A 70 W thulium-doped all-fiber laser operating at 1940 nm

“…Fiber-based laser sources comprising continuous-wave (CW) [1][2], nanosecond [3][4][5], picosecond [6][7][8], femtosecond [9][10][11] fiber lasers and amplifiers as well as supercontinuum sources [12][13][14] offer the efficient generation of laser radiation from compact lowmaintenance devices, which have created a wide range of applications in the industry. Especially medical applications like surgery of soft biological tissues have gained a lot of interest recently [15][16][17].…”

Supercontinuum generation without residual pump peak through multiple coherent pump seeds

“…After that, SCGs in fibers were widely investigated. [3][4][5][6][7] In order to obtain broadband supercontinuum, researchers adopted various pump seeds from soliton pulse, 4) Q-switched pulse, 8) noise-like pulse 9,10) to dissipative soliton resonance, 11) and special fibers from the ZBLAN fiber, 12,13) photonic crystal fiber based on As 2 Se 3 chalcogenide glass 14) to tellurite fiber with all-normal dispersion. 15,16) The supercontinuum could cover the wavelengths from ultraviolet to infrared spectra, 3,7,[11][12][13][14][15][16][17][18][19] bringing wider applications.…”

“…[3][4][5][6][7] In order to obtain broadband supercontinuum, researchers adopted various pump seeds from soliton pulse, 4) Q-switched pulse, 8) noise-like pulse 9,10) to dissipative soliton resonance, 11) and special fibers from the ZBLAN fiber, 12,13) photonic crystal fiber based on As 2 Se 3 chalcogenide glass 14) to tellurite fiber with all-normal dispersion. 15,16) The supercontinuum could cover the wavelengths from ultraviolet to infrared spectra, 3,7,[11][12][13][14][15][16][17][18][19] bringing wider applications. However, it is also found that the generated supercontinuum is not always flat due to the existence of a residual spectral peak at the pump wavelength 6,8,[11][12][13]17,18) which should be filtered in practical applications.…”

“…15,16) The supercontinuum could cover the wavelengths from ultraviolet to infrared spectra, 3,7,[11][12][13][14][15][16][17][18][19] bringing wider applications. However, it is also found that the generated supercontinuum is not always flat due to the existence of a residual spectral peak at the pump wavelength 6,8,[11][12][13]17,18) which should be filtered in practical applications. So far, only a few techniques have been put forward, such as cascading specific optical fibers 20) and designing special photonic crystal fiber, 21) to remove the residual pump peak in the supercontinuum.…”