Encouraged by the increasing requirements of intelligent equipment, silicon integrated circuit–compatible photodetectors that support single‐chip photonic–electronic systems have gained considerable progresses. Advanced materials have resulted in enhanced device performance based on traditional photovoltaic effect and photoconductive effect, and novel device designs have catalyzed new working mechanisms combing rapid photoresponse and high responsivity gain. Surprising applications are developed using monolithic photonic–electronic platforms, and the developing integration strategies keep pace with the developing complementary metal‐oxide‐semiconductor techniques as well as nonsilicon substrates. Here, the recent developments in silicon‐compatible photodetectors, both in device advances and their integration routes, are reviewed. Meanwhile, the progresses, challenges, and possible future directions in this field are discussed and concluded.

Ultra-compact mode-order converters with dielectric slots are demonstrated on a silicon-on-insulator platform. We propose a mode converter that converts the TE0 mode into the TE1 mode with an ultra-small footprint of only 0.8 × 1.2 µ m 2 . The measured insertion loss is less than 1.2 dB from 1520 nm to 1570 nm. To reduce the insertion loss, we further optimize the structure and design two mode converters that convert the TE0 mode into the TE1 mode and the TE2 mode with footprints of 0.88 × 2.3 µ m 2 and 1.4 × 2.4 µ m 2 , respectively. Their measured insertion losses are both less than 0.5 dB. Additionally, the proposed devices are cascadable and scalable for high-order mode conversion.

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Gripping small objects requires tool tips of comparable dimensions. Current methods for miniaturizing an MEMS tool entirely down to sub-micrometer in dimensions, however, come with significant tradeoffs in device performance. This paper presents a microfabrication approach to selectively miniaturize gripping tips only to sub-micrometers in thickness. The process involves using the thin buried SiO 2 layer of a standard silicon-on-insulator wafer to form gripping tips, and using the thick device silicon layer to construct high-aspect-ratio structures for structural, sensing, and actuation functions. The microgrippers with thin gripping tips (i.e. fingernail like) were experimentally characterized and applied to gripping 100 nm gold spheres inside a scanning electron microscope.