Eyesafe high peak power pulsed fiber lasers limited by fiber nonlinearity

Abstract

a b s t r a c tWe present design and performances of several eye-safe high peak power fiber lasers operating either around 1550 nm or 2000 nm. They share the limitations by nonlinear effects either Stimulated Brillouin Scattering for single frequency lasers or Kerr related effects for short pulse amplifiers. Performances above 1 kW peak power for single frequency lasers and 26 nJ for short pulse fiber lasers are reported. The influence of the saturation power of the fibers on the non-linearity is discussed and applied to a comparison between Erbium and Ytterbium co-doped fibers and Thulium doped fibers. The Brillouin gain properties in these fibers are also compared.

Soliton mode-locked fiber laser based on topological insulator Bi_2Te_3 nanosheets at 2 μm

“…It is known that the 2 μm wavelength region covers various gas absorption lines (e.g., H 2 O, CO, and CO 2 ) which may be useful in atmospheric sensing [22,23] and also it is deemed as the most promising pump band for wavelength conversion to the mid-infrared molecular fingerprint region [e.g., for ZnGeP 2 -based optical parametric oscillator (OPO)] [24] and supercontinuum generation [25,26]). The ultra-wide gain spectrum of thulium or holmium-doped fibers at 2 μm makes them favorable to generate ultrafast mode-locked pulses.…”

Efficient extraction of high pulse energy from partly quenched highly Er3+-doped fiber amplifiers

“…Figure 5(b) shows the average-power spectrum. With 40 kW of peak power, the nonlinear effect of four-wave mixing generates sidebands (e.g., [7,17,18]) containing ∼44% of the energy. Sideband energy is included in all reported energies, but is negligible in most cases.…”

“…In the absence of quenching, high-energy pulse amplification in rare-earth-doped fiber amplifiers, including EDFAs, is well understood [1][2][3][4][5][6][7][8][9][10][11]17,[45][46][47][48]. In the unquenched case, amplified spontaneous emission (ASE) or spurious lasing limits the energy that can be extracted (E extractable ) in a high-energy signal pulse to a few times the intrinsic saturation energy E IS , or say, at most 10 times [46][47][48] if the stored energy and the extraction efficiency are both at their practical limits.…”

“…Erbium-doped fiber amplifiers (EDFAs) and lasers enable versatile and compact optical sources in the wavelength range of ∼1.5-1.6 µm (e.g., [1][2][3][4][5][6][7][8][9][10][11]), and can readily be cladding-pumped with over 100 W of power from 980-nm diode lasers at low cost. Their wavelength range offers good atmospheric transmission and relative "eye-safety", highly desirable for LIDAR [2,10,12], remote sensing, and imaging [13].…”

Development of an All‐Fiber Coherent Beam Combining System toward High Energy Pulse Fiber Lasers

“…One of the main methods to generate high energy pulsed FL is a master oscillator power amplifier (MOPA) system, which combines main oscillator with high beam quality and optical fiber amplifier with high power [1,2]. However, when pulse laser with high peak power is amplified using optical fiber amplifier, if the intensity of the pulse laser reaches a certain value, various nonlinear optical effects occur inside fiber amplifying medium, which restrict the output intensity and the propagation length of pulse beam [3,4].…”