All-fiber highly chirped dissipative soliton generation in the telecom range

Abstract

A high-energy (0.93 nJ) all-fiber Erbium femtosecond oscillator operating in the telecom spectral range is proposed and realized. The laser cavity built of commercially available fibers and components combines non-PM and PM parts providing stable generation of highly-chirped (chirp parameter 40) pulses compressed in an output piece of standard PM fiber to 165 fs. The results of numerical simulation agree well with experiment. The analyzed intracavity pulse dynamics enables the classification of the generated pulses as dissipative solitons. © http://dx.doi.org/10.1364/ao.XX.XXXXXX Recent progress in the development of high-power femtosecond fiber lasers operating around 1 µm, based on the highlychirped dissipative solitons (HCDS) generated in all-normal dispersion (ANDi) laser cavities [1][2][3] paved the way for the transfer and expansion of this technology into other spectral regions. The first natural candidate would be the telecom window (∼1.5 micron), where high power mode-locked fiber lasers have a wide range of practical applications, from CARS spectroscopy [4] to few-cycle pulse synthesis [5], terahertz-wave generation [6], frequency metrology [7,8] and, of course, telecommunications [9]. The advantage of this spectral interval is the availability of various low cost telecom components that might make such lasers commercially attractive.For the most of practical applications, long-term stability and reliability as well as output power, pulse duration and output beam quality are five important laser characteristics. From this point of view, all-fiber lasers have advantages due to their compactness, relative simplicity of the schemes, high efficiency and perfect beam quality. There is though one quite important weakness -a polarization state that is undefined in standard single-mode fibers (SMFs) leading to uncontrollable variation with the changing environment, especially in a long enough fiber cavity. Polarization maintaining (PM) fibers are widely used to mitigate this problem. As a result, 150 fs, 25 pJ pulses were demonstrated recently in an all-fiber all-PM Erbium laser with graphene saturable absorber (GSA) operated in the anomalous net dispersion regime [10]. Slightly higher energy (44 pJ) for 174 fs pulses was demonstrated previously in non-PM cavity with GSA [11]. Another type of saturable absorber, topological insulator (TI) was also successfully demonstrated in an all-fiber configuration resulting in 130-fs 45-pJ pulses [12].Further energy up-scaling became possible by realizing the HCDS in the normal net dispersion regime, one of the most advanced ways to generate high-energy femtosecond pulses in mode-locked oscillators demonstrated so far, see review [13]. We have studied the HCDS regime earlier [14], showing an essential result used in the current publication, namely that the numerical simulations and analytical solution in the high chirp limit ( f 1) agree well at f > 10. The HCDS regime was experimentally demonstrated for the first time in Ytterbium [15] and Erbium fiber oscillators [16...

Dissipative soliton with sidebands on spectrum in an all-fibre laser

“…Based on our experimental results, the pulse shape had not been destroyed by the nonlinear phase shift. The compression ratio was 15.7:1, which was lower than some other reports [25], but the TBP was calculated as 1.004, which was very close to the transmission limit.…”

All-polarization-maintaining figure-of-9 soliton and dispersion-managed Er-doped fiber oscillators

“…Nonlinear polarization evolution (NPE) based mode-locked fiber lasers [7][8][9] are sensitive to environmental fluctuations due to their nonpolarization-maintaining (PM) configuration. A recent work [10] demonstrated a NPE mode-locked hybrid cavity with both PM and non-PM fibers supports a high energy (0.93 nJ) and short pulse duration (165 fs) output. However, the use of non-PM fibers might still lead to a long-time stability problem.…”

Large Normal Dispersion Mode-Locked Erbium-Doped Fiber Laser

“…The implementation of ANDI lasers using low nonlinearity large mode area fibers combined with a strong mode-locking mechanism resulted in the generation of ultrashort pulses with multi-MW peak powers and more than 1 µJ energy [5][6][7][8]. The implementation of this concept with erbium-doped fiber lasers operating around 1.55 µm has allowed energies of more than 20 nJ with sub-picosecond pulses to be reached [9][10][11][12][13][14]. Unfortunately, commercially available normal dispersion active fibers exhibit a small effective area for moderate dispersion values, thus limiting the energy scaling potential of this concept.…”