Atomic optical amplifier with narrow bandwidth optical filtering

TL;DR

This paper presents a novel atomic optical amplifier called SAFADOF that combines narrow bandwidth filtering with high gain, enabling effective amplification of weak signals with noise rejection, suitable for weak signal detection.

Contribution

The paper introduces SAFADOF, a new device that integrates atomic stimulated emission with narrow bandwidth filtering for enhanced weak signal amplification.

Findings

Gain factor exceeds 25000 (44 dB) for 50 pW signals.

Bandwidth as narrow as 13 MHz achieved.

Effective noise rejection demonstrated.

Abstract

Taking advantages of ultra-narrow bandwidth and high noise rejection performance of the Faraday anomalous dispersion optical filter (FADOF), simultaneously with the coherent amplification of atomic stimulated emission, a stimulated amplified Faraday anomalous dispersion optical filter (SAFADOF) at cesium 1470 nm is realized. The SAFADOF is able to significantly amplify very weak laser signals and reject noise in order to obtain clean signals in strong background. Experiment results show that, for a weak signal of 50 pW, the gain factor can be larger than 25000 (44 dB) within a bandwidth as narrow as 13 MHz. Having this ability to amplify weak signals with low background contribution, the SAFADOF finds outstanding potential applications in weak signal detections.