A sub-nanoliter, light-tolerant (780 µW/mm2), and power-adaptive forward-bulk optoelectronic microsystem for tetherless neural recording is presented. The CMOS bulk is used as a power harvester to utilize photogenerated carriers and a lower transistor threshold voltage for low power design (~0.3 µA at ~0.32 V). Increasing optical power boosts the system bandwidth to 14 kHz and the sampling frequency to 18.2 kHz, while maintaining the integrated input-referred noise (~10 µVRMS) stable, with an NEF of 2.34.

Tightly integrated optical interconnects can provide high-bandwidth, energy-efficient inter-node communication. We describe a novel system which uses hybrid 2.5D/3D integration to compose a state-of-the-art FPGA compute chiplet, three electrical interface chiplets, and three photonic interface chiplets. We use register-transfer-, gate-, transistor-, and device-level simulations to demonstrate the potential for this system to achieve 96Tb/s of bi-directional bandwidth, and we experimentally demonstrate key components including a complete opto-electrical channel. Our results provide a strong case for hybrid 2.5D/3D integration as the key enabler for scaling co-packaged optical interconnects.

We demonstrate a dense, highly parallel, and scalable multi-channel transceiver array for photonic chip-to-chip links. A CMOS electronic chip is flip-chipped onto a silicon photonic chip with 25 μm-pitch bumps to enable 0.8 Tbps data transmission through a single fiber utilizing a comb laser at a record bandwidth density of 5.3 Tbps/mm2. The unit transmitter and receiver cells inside the 80 channel-array incorporate high speed circuitry to drive, read from, and tune the photonic elements, while only occupying 25 μm × 75 μm each.

We present the elements of a pH-measuring autonomous microsystem, a Redox-Enabled Microscale Opto-Electronically Transduced Electrode (ReMOTE). The ReMOTE contains two electrodes of different materials, where the nearby$\mathbf{pH}$dictates the voltage between the two electrodes. The ReMOTE is a tetherless, all-optical microsystem which is powered and is transmitting its data optically. The ReMOTE is designed in a 180 nm CMOS SOI process, occupies merely$\mathbf{417}\ \mu \mathbf{m}\times \mathbf{48}\ \mu \mathbf{m}$, and it only consumes$\mathbf{2}\ \mu\mathbf{W}$. For the functional verification, we have conducted pH measurements using a thin film titanium nitride working electrode and a Ag/AgCl reference electrode, of which the voltage per pH sensitivity was 42.53 mV/pH.