Programmable fiber-based picosecond optical pulse shaper using time-domain binary phase-only linear filtering

Abstract

We demonstrate a fiber-based programmable arbitrary picosecond optical pulse shaper using binary phase-only linear filtering. The reconfigurable filtering operation is implemented in the time domain using an electro-optical phase modulator driven by a high-speed bit pattern generator. The required binary phase code is designed using a genetic algorithm. Precise matching between the predispersive and postdispersive media in the system is achieved by use of a single linearly chirped fiber Bragg grating subsequently operated from its two input ends. As a proof of concept, different pulse waveforms of practical interest are generated using this new pulse shaper.

625-MHz shape-to-shape update rate of a programmable all-fiber optical pulse shaper proved through an optical sampling oscilloscope

“…To the best of our knowledge, the shortest update time ever reported of about 30 ns has been obtained using a Gallium Arsenide (GaAs) SLM [2]. Recently we reported a programmable fiber-based pulse shaping system based on time-domain linear phase-only spectral filtering [4]. Here we demonstrate the capability of this scheme to obtain unprecedented shape-to-shape update rates, achieving a record update time of 1.6 ns.…”

“…The input optical pulse is temporally stretched using a first-order dispersive element (dispersion coefficient 2 β ) in such a way that the pulse amplitude spectrum is mapped along the time domain [4]. The required spectral phase filtering function is imposed onto the stretched pulse through an EO phase modulator driven by a bit-pattern generator (BPG) generating a binary pattern…”

Temporal pulse shaping using a continuous sampling function

“…However, the envelope profile of the generated pulse train is not flat. Very recently, Thomas et al proposed a fiber-based time-domain linear binary phase-only filtering system enabling arbitrary temporal reshaping of picosecond optical pulses [2]. However, since the in-band energy efficiency of the phase-only modulation function cannot reach 100%, the energy of one pulse may be extend to the neighboring pulses which will inevitably leading to the distortions existing in the amplitude of the resulted pulses.…”

Design of periodic binary fiber gratings for single and multiple flat-top pulse generation

“…Other structures, known as superstructured fiber Bragg gratings [2], have been used to generate rectangular pulses of 20 ps by phase and amplitude profiling of 2.5 ps soliton pulses. Both periodic FBGs and linearly chirped fiber gratings (LCFGs) have been applied for pulse rate multiplication [3] and pulse re-shaping [4][5][6], with the possibility of controlling the group-velocity dispersion and the spectral response independently. More recently, uniform long-period FBGs [7] have allowed us to reshape 600 fs and 1.8 ps Gaussian pulses into 1 ps and 3.2 ps flat-top pulses, respectively.…”