Work

Digital stabilization of an I/Q modulator in the carrier suppressed single-sideband mode for atom interferometry

Year: 2024

Type: article

Abstract: We present an all-digital method for stabilizing the phase biases in an electro-optic I/Q modulator for carrier-suppressed single-sideband (CS-SSB) modulation. Using programmable logic on the Red Pitaya STEMlab 125-14 platform, we digitally generate and demodulate an auxiliary radio-frequency tone whose beat with the optical carrier probes the I/Q modulator’s phase imbalances. We implement a multiple-input, multiple-output integral feedback controller that accounts for unavoidable cross-couplings in the phase biases to lock the error signals at exactly zero, where optical power fluctuations have no impact on phase stability. We demonstrate >23dB suppression of the optical carrier relative to the desired sideband at +3.4GHz over a period of 15 h and over temperature variations of 20°C.

Source: Applied Optics

DOI: 10.1364/ao.540890

Authors: Arif Ullah, Samuel Legge, John D. Close, Simon A. Haine, Ryan J. Thomas

Institution: Australian National University

Language: English

Topic: Advanced Photonic Communication Systems

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: green

Funders: Australian Research Council, Australia-India Strategic Research Fund

Awards: Advanced Quantum Sensors for Next-Generation Sensing Applications, G216074158, Creating high flux degenerate quantum atomic sources with active feedback, G6941331377