Wideband, Efficient Optical Serrodyne Frequency Shifting with a Phase Modulator and a Nonlinear Transmission Line

TL;DR

This paper demonstrates a wideband, efficient optical frequency shifting technique using a phase modulator driven by a nonlinear transmission line, achieving high efficiency over a broad frequency range.

Contribution

It introduces a novel implementation of serrodyne frequency shifting with a fiber-coupled electro-optical modulator and nonlinear transmission line, expanding bandwidth and efficiency.

Findings

Achieved frequency shifting from 350 to 1650 MHz.

Efficiency ranged from 35% to 80%.

Effective for 850 nm laser light.

Abstract

We report shifting of the frequency of an 850 nm laser with an instantaneous bandwidth of (350-1650), MHz and an efficiency between 35% (minimum) to 80% (best at frequencies around 600 and 1500, MHz) by phase modulation with a sawtooth waveform ("serrodyne frequency shifting"). We use a fiber-coupled traveling wave electro-optical modulator driven by a nonlinear transmission line.