Passively mode-locked fiber laser based on symmetrical nonlinear optical loop mirror

Abstract

Abstract:We propose and demonstrate a passively mode-locked Erbium-doped fiber laser based on symmetrical nonlinear optical loop mirror. The nonlinear optical loop mirror with intensitydepended transmission can act as an equivalent saturable absorber, which results in passively mode-locking of fiber laser. Pulse trains with fundamental cavity frequency and its various harmonic frequencies have been obtained.

All-fiber dual wavelength passive Q-switched fiber laser using a dispersion-decreasing taper fiber in a nonlinear loop mirror

“…The NOLM has been proven to possess an optical switching characteristic [16] which is comparable to a saturable absorber operation [15,27], and the use of NOLM for modelocking and Q-switching has been widely reported [18,19]. The NOLM is constructed from a 3 dB fiber coupler that has the two output ports connected together, and it exploits the effect of nonlinear propagation in a loop structure.…”

“…Nonlinear loop mirrors (NOLM) have been investigated for suitability as intensity dependent transmission (IDT) devices, with reports on applicability as a solid state fast saturable absorber [15], and for use in ultrafast processing [16], pulse shaping and compression [17], mode locking [18] and Q-switching [19]. NOLM can achieve IDT via an asymmetrical loop with unequal splitting ratios of intensities [16], in which the accumulation of the nonlinear phase shift due to self-phase modulation effect is exploited [20].…”

“…NOLM can achieve IDT via an asymmetrical loop with unequal splitting ratios of intensities [16], in which the accumulation of the nonlinear phase shift due to self-phase modulation effect is exploited [20]. IDT can be otherwise realized by a symmetrical NOLM with intensities that are equally split and operates on the principle of accumulation of the nonlinear phase shift due to nonlinear polarization rotation [18]. A novel NOLM has been reported to achieve IDT via progressively decreasing the diameter of a particular type of fiber to decrease dispersion [21].…”

Multiwavelength generation based on a mode-locked fiber laser using carbon nanotube and fiber Fabry–Perot filter

“…Using CNT as a passive mode-locked medium offers obvious advantages, including high nonlinearity, ultrafast recovery time of absorption, broadband operation, low cost, compatibility with fiber, and simple fabrication process. Generally, passively mode-locked fiber lasers can be achieved through the nonlinear optical loop mirror, nonlinear polarization rotation (NPR), and semiconductor saturable absorber mirror (SESAM) [2][3][4]. The passive mode-locked laser using CNT as a saturable absorber normally has a compact structure and shows flexibility in practical application, for instance, all-fiber technology.…”

Wavelength-tunable picosecond pulses from a passively mode-locked figure-eight Erbium-doped fiber laser with a Sagnac fiber filter

“…Many mode-locking techniques have been reported to implement a passive modelocked laser including semiconductor saturable absorber, nonlinear amplifier loop mirror (NALM), nonlinear optical loop mirror (NOLM) and nonlinear polarization rotation with a polarizer. Configurations that include a NOLM or a NALM are called figure-eight fiber lasers (F8L) [12]- [15]. The NOLM is usually formed by an asymmetrical coupler whose output ports are connected to form a loop [16].…”