Reduction of laser intensity noise over 1 MHz band for single atom trapping

TL;DR

This paper presents a method to significantly reduce laser intensity noise over a 1 MHz band using electro-optic and acousto-optic modulators, enhancing single atom trapping stability and lifetime.

Contribution

The authors introduce a noise reduction technique combining electro-optic and acousto-optic modulators, improving laser stability for optical trapping applications.

Findings

Laser noise reduced by up to 15 dB at critical frequencies.

Atomic trap lifetime increased by an order of magnitude to around 6 seconds.

Technique is broadly applicable to sensitive optical trapping setups.

Abstract

We reduce the intensity noise of laser light by using an electro-optic modulator and a cousto-optic modulator in series. The electro-optic modulator reduces noise at high frequency(10 kHz to 1 MHz), while the acousto-optic modulator sets the average power of the light and reduces noise at low frequency (up to 10 kHz). The light is then used to trap single sodium atoms in an optical tweezer, where the lifetime of the atoms is limited by parametric heating due to laser noise at twice the trapping frequency. With our noise eater, the noise is reduced by up to 15 dB at these frequencies, and the lifetime is increased by an order of magnitude to around 6 seconds. Our technique is general and acts directly on the laser beam, expanding laser options for sensitive optical trapping applications.