Pulse shaping, compression, and pedestal suppression employing a nonlinear-optical loop mirror

Abstract

We study the shaping of picosecond-duration optical pulses by the intensity-dependent transmission characteristics of a fiber loop mirror in the normally dispersive region. Experimental results for sech(2) intensity input profiles are in good agreement with the theoretical predictions. In addition, input pulses with substantial background radiation emerge both compressed and pedestal free.

Gain Dependent Optimum Pulse Generation Rates of a Hybrid-Type Actively and Passively Mode-Locked Fiber Laser

“…The average laser power and peak pulse power were measured and calculated to be about 0.44 mW and 167.1 W, respectively. The autocorrelation measurement shows strong side lobe structures beside the central strong peak pulse, which are the typical structures of high power pump cases for the nonlinear loop [2], [24],…”

Nonlinear loop mirror-based all-optical signal processing in fiber-optic communications

“…Note that the loss or gain-imbalanced NOLM provides higher discrimination against lowpower radiation than a coupler-imbalanced NOLM [71] owing to its approximate amplitude cubing effect at low powers (see (1)). On the contrary, the transfer function of a coupler-imbalanced NOLM [65] rises linearly at low powers. But since the loss or gain-imbalanced NOLM has sharper swtiching peaks, the portion of the switching curve on which operation is stable is smaller.…”

“…We operate the system such that the peak power P 0,in of the input pulses is slightly past the first peak of the CW characteristic curve [31][32][33][34][35][36]. A CW analysis shows that this region permits operational points that are stable against small fluctuations in the input power [65,79]. We also require equalization of the pulse peak power at the input and the output of the system.…”

“…The principle of the regeneration function of the NOLM is as follows: lowintensity noise and dispersive waves are filtered out from the higher-power pulses through an effective saturable absorption action [65]. This allows for restoration of the pulse amplitude and shape [30][31][32][33][34][35][36].…”

“…These include optical switching [50][51][52][53][54][55], phase conjugation [56], wavelength demultiplexing [57][58][59], mode-locking [60][61][62][63][64], pulse compression and pedestal suppression [65][66][67][68][69]. Earlier studies [70][71][72][73][74] have addressed the use of NOLMs to reshape and stabilize soliton pulses.…”