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An ultra-narrow 40-nm slotted waveguide is fabricated to enable highly efficient, electro-optic polymer modulators. Our measurement results indicate thatV_πL’s below ∼ 1.19 V.mm are possible for the balanced Mach-Zehnder modulators using this ultra-narrow slotted waveguide on a hybrid silicon-organic hybrid platform. Our simulations suggest thatV_πL’s can be further reduced to ∼ 0.35 V.mm if appropriate doping is utilized. In addition to adapting standard recipes, we developed two novel fabrication processes to achieve miniaturized devices with high modulation sensitivity. To boost compactness and decrease the overall footprint, we use a fabrication approach based on air bridge interconnects on thick, thermally-reflowed, MaN 2410 E-beam resist protected by an alumina layer. To overcome the challenges of high currents and imperfect infiltration of polymers into ultra-narrow slots, we use a carefully designed, atomically-thin layer of TiO₂as a carrier barrier to enhance the efficiency of our electro-optic polymers. The anticipated increase in total capacitance due to the TiO₂layer is negligible. Applying our TiO₂surface treatment to the ultra-narrow slot allows us to obtain an improved index change efficiency (∂n/∂V) of ∼ 22% for a 5 nm TiO₂layer. Furthermore, compared to non-optimized cases, our peak measured current during poling is reduced by a factor of ∼ 3.

 

Artificial intelligence and neuromorphic computing driven by neural networks has enabled many applications. Software implementations of neural networks on electronic platforms are limited in speed and energy efficiency. Neuromorphic photonics aims to build processors in which optical hardware mimic neural networks in the brain. 

Neuromorphic photonics exploit optical device physics for neuron models, and optical interconnects for distributed, parallel, and analog processing for high-bandwidth, low-latency and low switching energy applications in artificial intelligence and neuromorphic computing. 

Active control of interference is necessary with increased cell density, more complicated environmental reflections, and coexistence of multiple networks for next-generation wireless communications. The existing radio receiver architectures for spatial interference cancellation (SpICa) are limited by the spatial nulls created by a phased-antenna array (PAA) and cannot cover wide modulated bandwidths (BWs). We propose a discrete-time-delay-compensating technique for canceling spatial interferences with wide modulated BWs to reduce the dynamic range requirement for the data converter. Integral to the proposed circuit is a switched-capacitor-based multiply-and-accumulate processor that incorporates a reconfigurable phase interpolator and time interleaver for precise digitally tunable delays and multiplication of the input signal to an orthogonal matrix. The digital time interleaver enables 5-ps resolution with a reconfigurable range up to 15 ns. The measured results demonstrate greater than 35-dB SpICa over 80-MHz modulated BWs in the 65-nm CMOS with 52 mW of power consumption.