High-repetition-rate mode-locked ultrashort pulse sources greatly facilitate versatile photonic applications. Here, a mechanically actuated soliton microcomb oscillator is realized with a microwave repetition rate of 15 GHz in an ultrahigh-Q crystalline microresonator. This enables direct initiation, subsequent long-term stabilization, and fine tuning of soliton combs without pump laser tunability that is generally required for soliton microcomb operation. Abstract Mode-locked ultrashort pulse sources with a repetition rate of up to several tens of gigahertz greatly facilitate versatile phot ..read more

A direct convolution computing method based on wavelength routing, utilizing the unique sliding property of an arrayed waveguide grating router (AWGR) to perform the sliding window operation of the convolution in the wavelength-space domains is proposed and demonstrated. With two inputs vectors directly loaded onto modulator arrays, the convolution result is instantaneously produced at a photodetector array. Abstract Optical convolution computing is gaining traction owing to its inherent parallelism, multi-dimensional processing, and energy efficiency. To handle input dimensions of N, conven ..read more

Thermochromic luminescent materials (TLMs) Cs7Cd3Br13:Mn2+,Mg2+ screening by Cs–Cd–Br ternary phase diagram is reported. Such TLMs exhibit a reversible emission from bright yellow to green due to the tunable crystal field environment caused by phase transition. The characteristic of these TLMs shows great promise in temperature visualization applications. Abstract Thermochromic luminescent materials (TLMs) with spectral responsiveness to thermal stimuli have received broad attention due to the forefront applications in temperature visualization and sensing technologies. Herein, a phase diagr ..read more

Random fiber lasers have become a vigorous research area with unique advantages over the past decades. Benefiting from good temporal stability, wavelength tunability, low coherence, etc., random fiber lasers provide platforms for high-performance lasing generation. This study reviews the recent research progress on the spectral manipulation of random fiber lasers and their applications. Abstract Random fiber lasers (RFLs), a new variety of random lasers, have become a vigorous research spot over the past decades. RFLs possess superiorities in efficiency, structural flexibility, directionalit ..read more

Raman spectroscopy relies on the principle of inelastic scattering of photons by substances, enabling nondestructive and fast detection of stress. A comprehensive review of Raman spectroscopy in characterizing residual stress within microelectronics manufacturing is presented, including basic principles, Raman-stress relation, wavelength selection, and specific applications, with the aim of advancing Raman spectroscopy as a stress characterization tool for microelectronics manufacturing. Abstract In the rapidly evolving era of information and intelligence,microelectronic devices are pivotal ..read more

In order to minimize the phase modulation error of the optical coordinate transformation and improve the performance of the orbital angular momentum (OAM) mode sorter, a novel approach to numerically solve the phase distributions of the unwrapper and phase corrector under non-paraxial conditions is proposed. The feasibility of the scheme is experimentally demonstrated by the metasurface-based optical vortex mode sorter. Abstract The optical coordinate transformation based on the ray model can flexibly and efficiently complete the manipulation of complex light fields through a pair of phase p ..read more

In this work, filter-less photodetectors with tunable and selective narrow response from 700 to 950 nm are designed for light detection and ranging (Lidar). Both high signal-to-noise ratio and fast response rates are demonstrated in the fabricated devices. As a result, proof-of-concept Lidar with ≈10 cm distance resolution is achieved. Abstract Light detection and ranging (Lidar), which utilizes scattered near-infrared (NIR) light to identify objects, has shown great potential in remote sensing, autonomous driving, robotic vision, etc. However, the intensity of the scattered NIR li ..read more

This work demonstrates the generation of electro-optic frequency-combs spanning over 2.4 GHz around 8 μm$\umu {\rm m}$ wavelength, using harmonically-rich RF signals. A Schottky-based modulator embedded in a silicon-compatible Ge-rich graded SiGe waveguide, operating in a wide long-wave infrared spectral band is used, paving the way toward fully integrated and tunable mid-infrared electro-optic frequency-comb generation systems. Abstract The development of compact systems operating in the long-wave infrared wavelength range is of high interest for spectroscopic and sensing applications. Ther ..read more

Laser direct machining of nanophotonic structures composed of arrays of hollow nanochannels embedded in glass is demonstrated. Flexible adjustment of channels dimensions and spacings opens new possibilities for versatile effective-index engineering. A gradient-index metaprism is fabricated and tested, as a demonstrator of custom phase functions accessible by metamaterials laser-engraved inside standard low-index dielectric materials and operating in the infrared spectral-range. Abstract All-dielectric nanophotonic devices are usually fabricated by engraving arrays of nanoholes at the surface ..read more

A white-box digital twin is proposed to realize real-time polarization tracking. The digital twin derived by rigorous polarization optics calculation accurately models the real system. Digital twin bypasses the loop of perturbation, sampling, and adjusting over the real system, and requires merely 9 samples to complete one-step tracking, which is averagely over 7 times faster than conventional SPGD. Abstract Tracking polarization in real-time is a long-term challenge. The conventional heuristic and gradient-descent-based algorithms for polarization tracking lack efficiency and interpretabili ..read more