Nonlinear Compression of Besselon Waves for High Repetition-Rate Subpicosecond Pulses Trains

TL;DR

This paper demonstrates a method to generate high-repetition-rate, subpicosecond pulse trains with low duty cycles using nonlinear spectral expansion and phase modulation techniques, advancing ultrafast laser pulse generation.

Contribution

It introduces a novel approach combining phase modulation and nonlinear spectral expansion to produce high-quality, high-repetition-rate pulse trains with ultra-low duty cycles.

Findings

Achieved pulse trains at 28 GHz, 56 GHz, and 112 GHz.

Generated subpicosecond pulses with duty cycle as low as 0.025.

Enabled doubling and quadrupling of repetition rates through spectral component cancellation.

Abstract

We theoretically and experimentally demonstrate the generation of high-quality low duty-cycle pulse trains at repetition rates of 28 GHz, 56 GHz and 112 GHz. Starting from a continuous wave we benefit from phase modulations in the temporal and spectral domains by applying a sinusoidal profile and a set of well-chosen $\pi$ shifts, respectively, to generate a train of modified besselons at doubled repetition rate. With further nonlinear spectral expansion in a normally dispersive fiber followed by dispersion compensation we achieve subpicosecond durations and a duty cycle as low as 0.025 at 28 GHz. Spectral cancelation of one component over two or four enables to further double or quadruple the repetition rate.