Brillouin light storage for 100 pulse widths

TL;DR

This paper demonstrates the first experimental realization of Brillouin light storage for 150 ps pulses, achieving a record 15 ns delay, significantly advancing optical delay line technology.

Contribution

The work extends Brillouin-based storage to ultra-short pulses, enabling delays of 100 pulse widths, which was previously limited by the narrow linewidth of the optoacoustic response.

Findings

Stored 150 ps pulses in acoustic waves for 15 ns

Successfully retrieved multiple amplitude levels and pulses

Achieved low distortion in pulse shape during retrieval

Abstract

Signal processing based on stimulated Brillouin scattering (SBS) is limited by the narrow linewidth of the optoacoustic response, which confines many Brillouin applications to continuous wave signals or optical pulses longer than several nanoseconds. In this work, we experimentally demonstrate Brillouin interactions at the 150 ps time scale and a delay for a record 15 ns which corresponds to a delay of 100 pulse widths. This breakthrough experimental result was enabled by the high local gain of the chalcogenide waveguides as the optoacoustic interaction length reduces with pulse width. We successfully transfer 150ps-long pulses to traveling acoustic waves within a Brillouin-based memory setup. The information encoded in the optical pulses is stored for 15 ns in the acoustic field. We show the retrieval of eight amplitude levels, multiple consecutive pulses and low distortion in pulse shape. The extension of Brillouin-based storage to the ultra-short pulse regime is an important step for the realisation of practical Brillouin-based delay lines and other optical processing applications.