Implementation of an Optical System for Signal and Power Transmission in Light Coils

Motivation: RF-induced heating and reduced image signal-to-noise ratio (SNR) due to crosstalk between adjacent cables are problematic in dense receive arrays. RF coils with fiber-optical connection can overcome these problems associated with metallic wires. Goal(s): To develop optical signal and power transmission units for MRI. Approach: An analog photonic link with Mach-Zehnder modulator was constructed for optical signal transmission, and GaAs-based photonic power converters were used for power-over-fiber supply of low-noise-amplifiers (LNA). Results: Image SNR and signal dynamic range of the photonic link are comparable with coaxial cable connection. Photonic power convertors can supply up to 10 LNAs in the receive chain. Impact: Fully optical signal and power transmission is feasible for RF coils. It enables extremely dense modular receive arrays by eliminating cable-crosstalk and overcoming RF induced heating problems.