Ultrashort pulse generation from binary temporal phase modulation

Abstract

We propose and numerically validate an all‐optical scheme to generate a train of optical pulses. Modulation of a continuous wave with a periodic binary temporal phase pattern followed by a spectral phase shaping enables us to obtain ultrashort pulse trains. An ideal step phase profile as well as a profile arisen from a bandwidth‐limited device is investigated. Analytical guidelines describing pulse train formation and their characteristics are provided. Pulses with a duration of a few picoseconds at a repetition rate of 10 GHz can be expected for realistic experimental conditions.

Space-time analogy and its application to design schemes borrowed from Fourier optics for processing ultrafast optical signals

“…Flattop pulse generation with a duty ratio of 50% is one of the examples of the space-time analogy application at a quarter of the Talbot condition. These pulses are obtained by sinusoidal [2][3][4] and binary [4][5][6] electrooptic phase modulations of a CW laser field after transmission of the field through an appropriate GDD circuit. This method can be used in ultrahigh-speed optical fiber communications for energy preserving modulation of the laser field intensity with high extinction ratio.…”

Space-time analogy and its application to design schemes borrowed from Fourier optics for processing ultrafast optical signals

“…Flat-top pulse generation with a duty ratio of 50% is one of the examples of the space-time analogy application at a quarter of the Talbot condition. These pulses are obtained by sinusoidal [2][3][4] and binary [4][5][6] electrooptic phase modulations of a CW laser field after transmission of the field through an appropriate GDD circuit. This method can be used in ultrahigh-speed optical fiber communications for energy preserving modulation of the laser field intensity with high extinction ratio.…”

Temporal Fresnel diffraction induced by phase jumps in linear and nonlinear optical fibres

“…This space/time duality has already been extremely fruitful and has stimulated numerous new concepts or interpretation in ultrafast optics such as temporal or spectral lenses [8,9], Fresnel lens [10], super resolution imaging [11], dispersion gratings [12] or two-wave temporal interferometers [13], to cite a few. Other studies have established links between the near-field propagation observed in diffraction and advanced applications for high repetition-rate sources when initial periodic phase modulation is converted into intensity pattern [14][15][16][17][18] in a process that can be linked to the Talbot array illuminators in the spatial domain [19]. However, despite the fact that coherent communications now heavily rely on the use of phase modulation, no explicit study of the space / time duality for a single phase step has been clearly reported so far.…”