Integrated optical phased arrays (OPAs) capable of adaptive beamforming and beam steering enable a wide range of applications. For many of these applications, a large scale 2-D OPA with full phase control for each radiating element is essential to achieve a functional low-cost solution. However, the scalability of such OPAs has been hampered by the optical feed distribution difficulties in a planar photonics process, as well as the high power consumption associated with having a large number of phase control units. In this paper, we present a two-chip solution low-power scalable OPA with a nonuniform sparse aperture, providing radiation pattern adjustment and feed distribution feasibility in a CMOS compatible silicon photonics process. The demonstrated OPA with a 128-element aperture achieves the highest reported grating-lobe-free field-of-view (FOV)-tobeamwidth ratio of 16 • /0.8 • , which is equivalent to a 484-element uniform array. This translates to at least 400 resolvable spots, 30 times more than the state-of-the-art 2-D OPAs. Moreover, by utilizing compact phase shifters in a row-column power delivery grid, we reduce the number of required drivers from 144 to 37. A high-swing pulsewidth modulation (PWM) driving circuit featuring breakdown voltage multipliers and soft turnon activation significantly reduces the power consumption of the system. The electronic driver chip and the integrated photonic chip are fabricated on a 65-nm CMOS process and a thick siliconon-insulator (SOI) silicon photonics process, occupying 1.7 mm 2 and 2.08 mm 2 of active area, respectively.

Optical phased arrays (OPAs) on integrated photonic platforms provide a lowcost chip-scale solution for many applications. Despite the numerous demonstrations of OPA transmitters, the realization of a functional OPA receiver presents a challenge due to the low received signal level in the presence of noise and interference that necessitates high sensitivity of the receiver. In this paper, an integrated receiver system is presented that is capable of on-chip adaptive manipulation and processing of the captured waveform. The receiver includes an optoelectronic mixer that down-converts optical signals to radio frequencies while maintaining their phase and amplitude information. The optoelectronic mixer also provides conversion gain that enhances the system sensitivity and its robustness to noise and interference. Using this system, the first OPA receiver with a two-dimensional aperture of 8-by-8 receiving elements is demonstrated which can selectively receive light from 64 different angles. The OPA receiver can form reception beams with a beamwidth of 0.75 • over an 8 • grating-lobe-free field of view.

The core requirements for point-of-care (POC) diagnostics necessitate low-cost, portability, easily integrated sample preparation, and quick measurement time. Frequency-shift based magnetic sensing is a measurement technique utilizing a complementary metal-oxide-semiconductor (CMOS) integrated-circuit (IC) chip for magnetic label detection. The sensing scheme leverages the low-cost manufacturing of IC chips while demonstrating the potential for multiplexing capabilities. In this article, we present modifications to this scheme for POC viability. We introduce a handheld reusable reader and a disposable open-well cartridge for the detection of nucleic acids and antigens. The diagnostic system utilizes a novel "magnetic freezing" technique to reduce measurement time, obviates baseline measurement before or during biological assay, and reduces sensor noise. We utilize these enhancements for the room temperature, amplification-free detection of a 31 base-pair DNA oligomer and the interferon-γ (IFN-γ) protein. We have demonstrated reliable measurements down to 100 pM for the DNA assay and 1 pM for the protein.

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