Cryogenic High-Speed Modulator with Non-volatile Tunability in Commercial Silicon Photonics

Next-generation cryogenic military EO/IR sensors are pushing the boundaries of performance with smaller pixel sizes, larger array formats, higher frame rates, and increased bit-depthŚdemanding both high spatial and temporal resolution for real-time imaging while operating at extremely low temperatures. These advancements significantly increase data bandwidth requirements, quickly approaching the physical limits of traditional copper-based interconnects. Optical interconnects present a compelling alternative, offering a commercially mature and scalable solution that not only overcomes bandwidth limitations but also delivers benefits in power efficiency, cost reduction, and seamless on-chip integration. Optical links provide an ultimate solution for this need since they can provide THz of bandwidths at extremely low loss (<0.5dB/km). Another great advantage of optical links for cryogenic sensors, is the minimal heat load delivered to the cryogenic stage as well as negligible thermal noise. Finally, aggregate data-rates in a single-mode fiber can be simply boosted by 8x-32x using simultaneous communication over multiple wavelengths via wavelength division multiplexing (WDM).While micro-ring modulator (MRM)-based optical transceivers have been demonstrated using advanced silicon photonics, no demonstration so far has addressed all critical needs of cryogenic low-power optical link suitable for cryogenic sensor read-out read-outs. MRM-based photonic transceivers are the most power efficient and compact modulators by more than an order of magnitude compared with MZI. Recently VCSEL-based optical transmitters have been also demonstrated for cryogenic applications; however, such transmitters (Tx) cannot support WDM and eventually cannot be co-packaged and integrated with sensors efficiently.áAlphacore proposes to solve these challenges through three thrusts:á1) Resonance Tuning of MRMs at Cryogenic Temperatures,á2) Designing High-speed Electro-optical Cryogenic MRMs, andá3) Co-design and Packaging of Electronics and Photonics for Sensors.Our solution enables advanced packaging with sensor/pixel dies, compatibility with standard optics for receiver side in O-band (1260-1360 nm) and does not require any power for tuning.á