  Integrated microwave photonics is an intriguing field that leverages
integrated photonic technologies for the generation, transmission, and
manipulation of microwave signals in chip-scale optical systems. In particular,
ultrafast processing and computation of analog electronic signals in the
optical domain with high fidelity and low latency could enable a variety of
applications such as MWP filters, microwave signal processing, and image
recognition. An ideal photonic platform for achieving these integrated MWP
processing tasks shall simultaneously offer an efficient, linear and high-speed
electro-optic modulation block to faithfully perform microwave-optic conversion
at low power, and a low-loss functional photonic network that can be configured
for a variety of signal processing tasks, as well as large-scale, low-cost
manufacturability to monolithically integrate the two building blocks on the
same chip. In this work, we demonstrate such an integrated MWP processing
engine based on a thin-film lithium niobate platform capable of performing
multi-purpose processing and computation tasks of analog signals up to 92 giga
samples per second at CMOS-compatible voltages. We demonstrate high-speed
analog computation, i.e., first- and second-order temporal integration and
differentiation with computing accuracies up to 98.1 %, and deploy these
functions to showcase three proof-of-concept applications, namely, ordinary
differential equation solving, ultra-wideband signal generation and high-speed
edge detection of images. We further leverage the image edge detector to enable
a photonic-assisted image segmentation model that could effectively outline the
boundaries of melanoma lesion in medical diagnostic images, achieving orders of
magnitude faster processing speed and lower power consumption than conventional
electronic processors.
