50 fs soliton compression of optical clock pulse recovered from NRZ data injected SOAFL

Abstract

Mode-locking of semiconductor optical amplifier fiber laser (SOAFL) with 50 fs pulses by extracting the clock of an optical non-return-to-zero (NRZ) data injection is demonstrated. The efficiency of mode-locking in the SOAFL is improved by increasing the seeding power of the large-duty-cycle NRZ data from 3 to 8 dBm into the SOA driven at biased current of 350 mA. After linear dispersion compensation, the mode-locked SOAFL pulsewidth can be further shortened from 20 to 3 ps by increasing the DCF length up to 110 m. By using a booster the EDFA to enlarge the average power of mode-locked SOAFL pulse to 1.3 W, the shortest soliton pulse is occurred after propagating through a 12-m-long SMF. The amplified SOAFL pulse can be compressed to 50 fs after nonlinear compression with its spectral linewidth broadening to 64 nm. Nearly transform-limited time-bandwidth product of 0.436 and the maximum pulse compressing ratio of 400 are reported to date.

Subpicosecond pulses in a self-starting mode-locked semiconductor-based figure-of-eight fiber laser

“…In our opinion, the physical mechanism underlying pulse formation in this system is the interaction between the counterpropagating pulses that is at work in colliding-pulse mode-locked lasers (see e.g., [17]), which is based on the ultrafast dynamics of the gain in active semiconductor systems as described in [18]. This same mechanism is, in our opinion, the one that leads to active ML by counterpropagating injection of external pulses, as, for example, in [9,10,19,20].…”

“…Active ML of SOA-based fiber lasers in unidirectional ring cavities has allowed researchers to obtain optical pulses with a duration of 15 ps [9], which can be further amplified and compressed down to 50 fs [10]. Exploiting nonlinear polarization rotation of the field in the SOA, passive ML has been achieved in different situations.…”

Hybrid Mode Locked Fiber Ring Laser

“…Several researchers have carried out experiments to either compress the optical temporal width or suppress the supermode noise to improve the laser stability. These schemes include (1) adiabatic soliton compression techniques [3][4], (2) multiple-step compression based on self phase modulation in highly nonlinear fibers or semiconductor optical amplifiers (SOA) [5][6], (3) a comb-like profiled fiber (CPF) to emulate dispersion decreasing fiber [7][8], (4) saturable optical absorbers such as nonlinear optical loop mirror (NOLM) [9][10][11].…”

12 GHz passive harmonic mode-locking in a 106 μm semiconductor optical amplifier-based fiber laser with figure-eight cavity configuration

“…Recently, semiconductor optical amplifiers (SOAs) have been used as the gain medium in fiber lasers [10][11][12]. Compared with the rare-earth-doped fibers, SOAs have many practical advantages, such as compact size, higher optical nonlinearity, larger gain bandwidth, and direct gain modulation by controlling injection current.…”

“…As a result, the energy in the upper state and the gains of SOAs are typically smaller than those of doped fibers, but the response of SOAs is much faster. Lin et al demonstrated the generation of a 50 fs pulse from a 1.55 μm SOA-incorporated fiber ring, which was operated under the optical injection-induced actively HML scheme [10]. Yang et al [11] demonstrated the generation of 800 fs optical pulses using a 1.55 μm SOA with the passive mode-locking technique of nonlinear polarization evolution.…”