Pure temporal dispersion for aberration free ultrafast time-stretch applications

TL;DR

This paper introduces a novel third-order dispersion compensation scheme enabling pure temporal dispersion in ultrafast time-stretch systems, significantly reducing aberrations and enhancing spectral resolution.

Contribution

It presents an optical phase conjugation method to achieve pure temporal dispersion with minimal aberrations, improving ultrafast time-stretch applications.

Findings

Achieved 3400-ps2 pure temporal dispersion over 30 nm bandwidth.

Reduced temporal aberrations to 2% using the new dispersion compensation.

Enabled record 15000 effective spectral points with 2-pm resolution.

Abstract

Photonic time-stretch overcomes the speed limitation of conventional digitizers, and enables the observation of non-repetitive and statistically rare phenomena that occur on short timescales. In most of the time-stretch applications, large temporal dispersion is highly desired to satisfy the far-field diffraction regime. However, most conventional spatial disperser or chirped fiber Bragg grating are constrained by its spatial volume, which can be overcome by the ultra-low-loss dispersive fiber, as an ideal medium for large temporal dispersion , while it suffers from the third-order dispersion and aberrations. In this paper, an optical phase conjugation based third-order dispersion compensation scheme is introduced, with accumulated dispersion and eliminated third dispersion, and achieved negative and positive 3400-ps2 pure temporal dispersion of over 30-nm bandwidth. Leveraging this pure temporal dispersion, up to 2% temporal aberrations have been eliminated; furthermore, a Fourier domain spectroscopy has achieved a record 15000 optical effective resolvable points, with non-degraded 2-pm resolution over 30-nm range