The silicon photonic optical phased array (OPA) featured by high integration and agile beam steering exhibits greatly potential application in optical wireless communication (OWC). In this paper, we demonstrate high-data-rate and long-range OWC using an integrated Silicon-Silicon Nitride OPA chip with 12 mm ² large aperture. The OPA chip constituted by 128 waveguide grating antennas at nonuniform spacing is employed for wide-steering and small-divergence solid beam steering. In the experiment, we demonstrated 100° wide range communications in horizontal direction via antenna phase tuning. To our best knowledge, 100° is the widest cover range in the reported OPA-based OWC systems. Moreover, the OPA chip is also utilized to achieve up to 32 Gb/s low BER transmission of non-return-to-zero (NRZ) signal over 54 m free space distance. In addition, we also successfully demonstrated more than 50 Gb/s PAM4 signal transmission by measuring clear eye diagrams at the horizontal direction of 0° and 50° over 10 m. Thanks to agile beam steering of the OPA, switching time among arbitrary positions in multi-targets communication can be less than 27 μs. By virtue of tiny beam divergence 0.021° × 0.029° emitted from the OPA, data transmission switching between two targets spaced at 3.5 cm over 20 m can be achieved accurately. The experimental measurement shows the sidelobe crosstalk from the adjacent target channel is less than -25.2 dB. Our demonstrations validate the feasible implementation of the silicon-based OPA in the high-data-rate and wide-steering-range OWC system.

We have proposed a time-domain extremum phase shift laser ranging method based on ergodic under-sampling to address the issues of high sampling rate and complex hardware implementation in conventional phase shift laser ranging systems. This method is combined with the spline interpolation algorithm to further enhance the range resolution and precision. Compared with traditional frequency domain phase shift laser ranging methods, our method has the advantages of a simpler calculation process, higher measurement precision, a lower sampling rate, and easier hardware implementation. We have set up a phase shift laser ranging system with an FPGA to test the viability of the proposed method. The proposed method has shown superior ranging performance than the conventional DFT frequency domain method. In addition, the use of the spline interpolation algorithm can further enhance the resolution and precision. We hope that this ranging method can provide a reference for reducing the hardware complexity of phase shift LiDAR and enhancing ranging precision.

Lead halide perovskite is a new photovoltaic material with excellent material characteristics, such as high optical absorption coefficient, long carrier transmission length, long carrier lifetime and low defect state density. At present, the steady-state photoelectric conversion efficiency of all-perovskite laminated cells is as high as 28.0%, which has surpassed the highest efficiency of monocrystalline silicon cells (26.7%). In addition to its excellent photovoltaic properties, perovskite is also a type of direct bandgap semiconductor with low cost, solubilization, high fluorescence quantum efficiency and tunable radiation wavelength, which brings hope for the realization of electrically pumped low-cost semiconductor lasers. In recent years, a variety of perovskite lasers have emerged, ranging from the type of resonator, the wavelength and pulse width of the pump source, and the preparation process. However, the current research on perovskite lasers is only about the type of resonator, the type of perovskite and the pump wavelength, but the performance of the laser itself and the practical application of perovskite lasers are still in the initial stages. In this review, we summarize the recent developments and progress of solution-processed perovskite semiconductors lasers. We discuss the merit of solution-processed perovskite semiconductors as lasing gain materials and summarized the characteristics of a variety of perovskite lasers. In addition, in view of the issues of poor stability and high current density required to achieve electrically pumped lasers in perovskite lasers, the development trend of perovskite lasers in the future is prospected.

A low-cost hybrid integrated narrow linewidth laser is proposed in this paper. The monolithically integrated 18- channel distributed feedback (DFB) narrow linewidth laser array with a wavelength interval of 0.8 nm is designed and precisely fabricated using reconstruction equivalent chirp (REC) technique, exhibiting good single-mode performance for each channel, with the typical linewidth less than 200 kHz. One channel of the laser array is integrated with the silicon nitride (Si₃N₄) external cavity chip through the photonic wire bonding (PWB) technique. Both the linewidth reduction effect of the passive external cavity and the coupling efficiency between chips by the polymer waveguide are numerically calculated. The compactly packaged device can be tuned to seven distinct self-injection-locked states with 0.4 nm spectral spacing, where the maximum linewidth is 10.9 kHz and the minimum linewidth is 9.1 kHz. Meanwhile, the side-mode suppression ratio (SMSR) is higher than 54.3 dB and the output power is 3.6 ± 0.9 dBm for each self-injection-locked state.

In this work, a regulated-voltage biasing configuration is proposed for the Ge-on-Si avalanche photodiode (APD) structure. This design incorporates an extended n-charge layer to decrease the breakdown voltage and optimizes the absorption region thickness to reduce the electron transit time. By applying three electrodes to individually modulate the electric fields in the absorption and avalanche region, respectively, both of low avalanche breakdown voltage (−8.1 V) and high bandwidth (20.4 GHz) of the surface-illuminated detector can be achieved. Meanwhile, the sensitivity of weak light detection is improved to −45 dBm. The responsivity of the APD is 60.76 A/W at 1550 nm when the voltage is biased at −13.5 V. The low voltage and improved bandwidth can meet the requirements for weak light detection and other applications demanding such sensitivity.

The development of high-performance, low-cost O-band multi-wavelength light sources has become increasingly critical, largely driven by the exponential bandwidth growth in short-reach optical communications, along with applications such as optical coherence tomography and time-resolved spectroscopy. Quantum dot mode-locked lasers exhibit distinct advantages including low threshold current, intrinsic repetition rate stability, and ultra-broad gain bandwidth, yet they are constrained by limited channel counts and broad linewidths. While O-band dissipative Kerr soliton microcombs operating in the anomalous dispersion regime offer a promising alternative, they suffer from low pump-to-comb conversion efficiency and fabrication challenges. To overcome these bottlenecks, we demonstrate a high-performance, 200-GHz-spacing O-band platicon microcomb with a high conversion efficiency of 17.3%, achieved via laser self-injection locking (SIL) to a high-quality-factor, normal-dispersion, 300-nm-thick silicon nitride microresonator without specialized dispersion engineering. Benefiting from laser SIL mechanism, the pump phase noise is significantly suppressed, resulting in a narrow intrinsic linewidth of 634.7 Hz. This work establishes a practical pathway toward scalable and energy-efficient O-band multi-wavelength light sources for advanced applications.