This article reviews the achievements in synthesis techniques and nanoscale optoelectronic applications based on one-dimensional metal–halide perovskite nanocrystals.

Zero-dimensional (0D) black phosphorus quantum dots (BPQDs), the new derivatives of black phosphorus (BP) nanomaterials, have attracted considerable attention since they were first prepared in 2015. Compared to traditional two-dimensional (2D) BP nanosheets, BPQDs exhibit some unique properties and demonstrate great potential for a broad range of applications, especially in the field of biomedicine. Due to the rapid development and substantial research interest in this area, it is urgent to review the current advances, challenges and near-future possibilities of BPQD-related biomedical research, which will benefit the further development of this field. This review is mainly focused on the latest progress of BPQD related applications in the biomedical field, including photothermal therapy (PTT), photodynamic therapy (PDT), drug delivery, biological imaging, etc. The challenges and future prospects are also discussed.

The thin-film lithium niobate (TFLN) modulator is among the most critical devices in photonic integrated circuits (PICs), owing to its large modulation bandwidth, low optical loss, and high extinction ratio. However, it suffers from DC drift issues at low frequencies or long timescales. Here, we have successfully alleviated the DC drift effect of the electro-optical phase shifter (EOPS) at low frequencies by employing a high-energy Ar ⁺ ion milling preprocessing. This EOPS can stably output square wave modulation signals at a frequency of 1 Hz, and the output signal exhibits no DC drift under DC voltage modulation within 1 h. Compared with the thermo-optical phase shifter (TOPS), the optimized EOPS not only has higher modulation rate but also exhibits the same stability at low frequency. Furthermore, we applied this ion milling technique to produce a TFLN modulator. At a DC bias voltage of 4.5 V, the bandwidth of the modulator is above 40 GHz and remained a stable output within 30 min.

Periodically poled lithium niobate on insulator (PPLNOI) offers an admirably promising platform for the advancement of nonlinear photonic integrated circuits (PICs). In this context, domain inversion engineering emerges as a key process to achieve efficient nonlinear conversion. However, periodic poling processing of thin-film lithium niobate has only been realized on the chip level, which significantly limits its applications in large-scale nonlinear photonic systems that necessitate the integration of multiple nonlinear components on a single chip with uniform performances. Here, we demonstrate a wafer-scale periodic poling technique on a 4-inch LNOI wafer with high fidelity. The reversal lengths span from 0.5 to 10.17 mm, encompassing an area of ~1 cm² with periods ranging from 4.38 to 5.51 μm. Efficient poling was achieved with a single manipulation, benefiting from the targeted grouped electrode pads and adaptable comb line widths in our experiment. As a result, domain inversion is ultimately implemented across the entire wafer with a 100% success rate and 98% high-quality rate on average, showcasing high throughput and stability, which is fundamentally scalable and highly cost-effective in contrast to traditional size-restricted chiplet-level poling. Our study holds significant promise to dramatically promote ultra-high performance to a broad spectrum of applications, including optical communications, photonic neural networks, and quantum photonics.