Broadband Optical Serrodyne Frequency Shifting

TL;DR

This paper demonstrates a simple, robust method for broadband optical frequency shifting using serrodyne modulation with high efficiency and a large tuning range, suitable for various optical applications.

Contribution

It introduces a high-fidelity sawtooth waveform generation via NLTL for efficient serrodyne frequency shifting from 200 MHz to 1.2 GHz with continuous tuning capabilities.

Findings

Achieved over 60% efficiency in frequency shifting

Demonstrated continuous tuning from -1.6 GHz to +1.6 GHz

Provided a simple, robust alternative to existing technologies

Abstract

We demonstrate serrodyne frequency shifting of light from 200 MHz to 1.2 GHz with an efficiency of better than 60 percent. The frequency shift is imparted by an electro-optic phase modulator driven by a high-frequency, high-fidelity sawtooth waveform that is passively generated by a commercially available Non-Linear Transmission Line (NLTL). We also implement a push-pull configuration using two serrodyne-driven phase modulators allowing for continuous tuning between -1.6 GHz and +1.6 GHz. Compared to competing technologies, this technique is simple and robust, and offers the largest available tuning range in this frequency band.