Long Light Storage Time in an Optical Fiber

TL;DR

This paper demonstrates a method to store light in an optical fiber for over 50 milliseconds using cold atomic vapor and EIT, enabling long delay times for quantum and classical information processing.

Contribution

It introduces a novel approach of loading cold Rb vapor into a hollow-core fiber to achieve long light storage times with low loss, advancing quantum optical delay line technology.

Findings

Achieved over 50 ms of light storage time.

Demonstrated low propagation loss equivalent to 8.7x10^-5 dB s^-1.

Potential applications in buffering quantum and classical information.

Abstract

Light storage in an optical fiber is an attractive component in quantum optical delay line technologies. Although silica-core optical fibers are excellent in transmitting broadband optical signals, it is challenging to tailor their dispersive property to slow down a light pulse or store it in the silica-core for a long delay time. Coupling a dispersive and coherent medium with an optical fiber is promising in supporting long optical delay. Here, we load cold Rb atomic vapor into an optical trap inside a hollow-core photonic crystal fiber, and store the phase of the light in a long-lived spin-wave formed by atoms and retrieve it after a fully controllable delay time using electromagnetically-induced-transparency (EIT). We achieve over 50 ms of storage time and the result is equivalent to 8.7x10^-5 dB s^-1 of propagation loss in an optical fiber. Our demonstration could be used for buffering and regulating classical and quantum information flow between remote networks.