Work

Spectrally-pure optical serrodyne modulation for continuously-tunable laser offset locking

Year: 2025

Type: article

Abstract: The comb-like spectrum added to laser light by an electro-optic modulator (EOM) finds use in a wide range of applications, including coherent optical communication, atomic spectroscopy, and laser frequency and phase stabilization. In some cases a sideband-free optical frequency shift is preferred, such as in laser offset locking using an optical cavity, single-photon frequency shifting, and laser range finding. Approaches to obtaining an optical frequency offset (OFO) involve trade-offs between shift range, conversion gain, and suppression of spurious sidebands. Here we demonstrate an OFO of continuous-wave 871 nm laser light by serrodyne modulation using a fiber EOM and radio-frequency (RF) tones from a commercial RF system on a chip (RFSoC) to achieve shifts of 40 to 800 MHz with >15 dB suppression of spurious sidebands and <1.5 dB conversion loss. We also observe a smoothly varying conversion gain. The utility of this tool is demonstrated by continuously shifting the offset of a cavity-locked laser from 50 to 1600 MHz, a capability useful in spectroscopy of unknown optical transitions.

Source: Optics Express

DOI: 10.1364/oe.569114

Authors: Roame A. Hildebrand, Wance Wang, Connor Goham, Alessandro Restelli, Joseph W. Britton

Institution: National Institute of Standards and Technology

Language: English

Topic: Advanced Fiber Laser Technologies

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,270

Funders: Army Research Laboratory, DEVCOM Army Research Laboratory