Near quantum-noise limited and absolute frequency stabilized 1083 nm single-frequency fiber laser

Opt Lett. 2018 Jan 1;43(1):42-45. doi: 10.1364/OL.43.000042.

Abstract

The Earth's magnetic field has significant effects that protect us from cosmic radiation and provide navigation for biological migration. However, slow temporal variations originating in the liquid outer core invariably exist. To understand the working mechanism of the geomagnetic field and improve accuracy of navigation systems, a high-precision magnetometer is essential to measure the absolute magnetic field. A helium optically pumping magnetometer is an advanced approach, but its sensitivity and accuracy are directly limited by the low-frequency relative intensity noise and frequency stability characteristics of a light source. Here, we demonstrate a near quantum-noise limited and absolute frequency stabilized 1083 nm single-frequency fiber laser. The relative intensity noise is only 5 dB higher than the quantum-noise limit, and the root mean square of frequency fluctuation is ∼17 kHz after locked. This fiber laser could suppress the fluctuation of magnetic resonant frequency and improve the signal-to-noise ratio of the magnetic resonance signal detection.