Direct Drive Optical Link for High Speed Cryogenic Data Readout

We propose the development of a low-power optical link to read-out data at 30 Gbps to 100 Gbps rates from a 4 K environment. Injection-locked lasers with low impedance can be directly driven by superconducting digital logic signals. This would eliminate the energy dissipated in the impedance transformation and amplification required to boost superconductor signals to drive traditional optical modulator structures. The type of laser proposed under this program is a novel whistle-geometry semiconductor ring laser (WRL). The WRL is injection locked by a master laser that could be incorporated inside (monolithically and efficiently coupled with the injection-locked laser) or incorporated outside of the 4 K environment. If incorporated inside, the master laser would allow efficient scaling to multiple channels, thru the"on-chip"integration with multiple modulators. We will develop a receiver system (on the 300 K side) that will perform the conversion of the RZ (pulsed) signals into a standard NRZ format.