Group‐10 transition metal dichalcogenides (TMDs) with distinct optical and tunable electrical properties have exhibited great potential for various optoelectronic applications. Herein, a self‐powered photodetector is developed with broadband response ranging from deep ultraviolet to near‐infrared by combining FA_1−xCs_xPbI₃ perovskite with PdSe₂ layer, a newly discovered TMDs material. Optoelectronic characterization reveals that the as‐assembled PdSe₂/perovskite Schottky junction is sensitive to light illumination ranging from 200 to 1550 nm, with the highest sensitivity centered at ≈800 nm. The device also shows a large on/off ratio of ≈10⁴, a high responsivity (R) of 313 mA W⁻¹, a decent specific detectivity (D*) of ≈10¹³ Jones, and a rapid response speed of 3.5/4 µs. These figures of merit are comparable with or much better than most of the previously reported perovskite detectors. In addition, the PdSe₂/perovskite device exhibits obvious sensitivity to polarized light, with a polarization sensitivity of 6.04. Finally, the PdSe₂/perovskite detector can readily record five “P,” “O,” “L,” “Y,” and “U” images sequentially produced by 808 nm. These results suggest that the present PdSe₂/perovskite Schottky junction photodetectors may be useful for assembly of optoelectronic system applications in near future.

Biocatalysis has attracted significant attention owing to its environmental-friendly nature, high efficiency, and remarkable selectivity for reactions. However, enzymes, which are powerful catalysts used in biocatalysis, suffer from low stability when used for long-term operations in solution and a gradual decrease in activity during storage. Microfluidic reactors are devices known for their smaller dimensions, large surface-to-volume ratios, and well-defined reaction times. Enzymes immobilized in such microfluidic reactors can exhibit distinct benefits, such as fast reaction rate, high storage stability, suppressed autolysis, and ease of use. The use of microfluidic immobilized enzyme reactors (μ-IMERs) offers several advantages over traditional technologies in performing biocatalytic reactions, such as low energy consumption, rapid heat exchange, fast mass transfer, high efficiency, and superior repeatability. In this review, the strategies of employing μ-IMERs for continuous biocatalysis have been investigated via a top-down approach. First, from the macroscopic perspective, the fabrication techniques of microfluidic reactors are presented encompassing materials, configurations, and technologies. Then, from the microscopic point of view, several strategies are discussed for the internal structural designs of microfluidic reactors. Moreover, when we move to the nanoscopic level, attention is paid to the choice of enzyme immobilization techniques for performance enhancement. Finally, the scalability of microfluidics that transfers biocatalysis from laboratory to industrial production was investigated. This review is intended to provide a guideline for using biocatalysis in microreactors and expediting the progress of this important research area.

Food production in green crops is severely limited by low activity and poor specificity of D-ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) in natural photosynthesis (NPS). This work presents a scientific solution to overcome this problem by immobilizing RuBisCO into a microfluidic reactor, which demonstrates a continuous production of glucose precursor at 13.8 μmol g⁻¹ RuBisCO min⁻¹ from CO₂ and ribulose-1,5-bisphosphate. Experiments show that the RuBisCO immobilization significantly enhances enzyme stabilities (7.2 folds in storage stability, 6.7 folds in thermal stability), and also improves the reusability (90.4% activity retained after 5 cycles of reuse and 78.5% after 10 cycles). This work mimics the NPS pathway with scalable microreactors for continuous synthesis of glucose precursor using very small amount of RuBisCO. Although still far from industrial production, this work demonstrates artificial synthesis of basic food materials by replicating the light-independent reactions of NPS, which may hold the key to food crisis relief and future space colonization.

Optical spectral measurements are crucial for optical sensors and many other applications, but the prevailing methods, such as optical spectrum analysis and tunable laser spectroscopy, often have to make compromises among resolution, speed, and accuracy. Optical frequency combs are widely used for metrology of discrete atomic and molecular spectral lines. However, they are usually generated by optical methods and have large comb spacing, which limits the resolution for direct sampling of continuous spectra. To overcome these problems, this paper presents an original method to digitally generate an ultrafine optical frequency comb (UFOFC) as the frequency ruler for spectral measurements. Each comb line provides one sampling point, and the full spectrum can be captured at the same time using coherent detection. For an experimental demonstration, we adopted the inverse fast Fourier transform to generate a UFOFC with a comb spacing of 1.46 MHz over a 10-GHz range and demonstrated its functions using a Mach-Zehnder refractive index sensor. The UFOFC obtains a spectral resolution of 0.01 pm and response time of 0.7 μs; both represent 100-fold improvements over the state of the art and could be further enhanced by several orders of magnitude. The UFOFC presented here could facilitate new label-free sensor applications that require both high resolution and fast speed, such as measuring binding kinetics and single-molecule dynamics.

We propose and experimentally demonstrate a novel ultra-long range and sensitive distributed fiber vibration sensor. Only one unidirectional Mach-Zehnder interferometer (MZI) is employed in this scheme as the sensing element. In this sensor structure, we utilize chromatic dispersion-induced walk-off effect between the vibration signals sensed by two distributed feedback (DFB) lasers at different wavelengths to locate the vibration position. Vibration signals with frequencies up to 9MHz can be detected and the spatial resolution of 31m is achieved over 320km of the standard single mode fiber. Monitoring multiple vibration sources can also be realized using this scheme.

We report a new design of optofluidic tunable lens with a 2D refractive index gradient generated by shining light onto a pair of metal strips.