设计合成了一种以蒽［2，3?b］苯并呋喃为核心的新型化合物，通过给体咔唑基团修饰得到化合物2?（蒽［2，3?b］苯并呋喃?3?基）?9?苯基?9H?咔唑（ABPCz）。经过掺杂器件研究，ABPCz可以实现蓝光发射，最大电流效率为8.79 cd/A，最大外量子效率为7.8%，CIE（0.17，0.23），峰值光谱448 nm，在476 nm处有较强的肩峰，在 1 000 cd/m²初始亮度下测试器件LT90（亮度衰减到初始亮度的90%）寿命达到153 h。结果表明，蒽［2，3?b］苯并呋喃经过咔唑基修饰可以得到高效、长寿命的蓝光器件，这为设计开发高性能蓝光材料提供了一个新途径。

In the past few years, many groups have focused on the research and development of GaN-based ultraviolet laser diodes (UV LDs). Great progresses have been achieved even though many challenges exist. In this article, we analyze the challenges of developing GaN-based ultraviolet laser diodes, and the approaches to improve the performance of ultraviolet laser diode are reviewed. With these techniques, room temperature (RT) pulsed oscillation of AlGaN UVA (ultraviolet A) LD has been realized, with a lasing wavelength of 357.9 nm. Combining with the suppression of thermal effect, the high output power of 3.8 W UV LD with a lasing wavelength of 386.5 nm was also fabricated.

Two-dimensional (2D) van der Waals materials have attracted tremendous attention due to their versatile physical properties and flexible manipulation approaches. Among the various types of van der Waals materials, α-In2Se3 is remarkable for its intrinsic 2D ferroelectricity and high-performance opto-electronic properties. However, the study of the α-In2Se3 system in terahertz (THz) radiation is scarce, although it is promising for electrically controlled THz field manipulation. We investigate the α-In2Se3 in different thicknesses and report that the THz generation efficiency induced by femtosecond laser pulses can be largely improved by reducing the thickness from the bulk. Furthermore, we reveal the surge current in thin film coupled with THz emission exhibits a different Auger recombination mode, which is helpful in understanding the mechanism and provides insights into the design of 2D highly efficient THz devices.

针对当前空间环境单一、红外波段探测目标虚警率高、灵敏度低等难题，提出了一种基于低温冷光学技术的双色红外光学系统设计方法。光学系统前置光路采用共口径式结构，通过分光平板进行谱段分光，然后采用中继镜组二次成像的方式实现冷阑匹配，保证系统的轻小型化。另外，为了提升长波系统的探测灵敏度，对其进行了低温冷光学设计，减小系统自身辐射对探测性能的影响。系统的工作波长为3.7~4.8 μm和7.9~9.3 μm，F数为1.2，光学结构三维总尺寸为260 mm×150 mm×80 mm，中波系统畸变小于2.8%，约有82%的能量集中在探测器的一个像元内，长波系统畸变小于0.33%，约有70%的能量集中在探测器的一个像元内。该系统可对空间弱目标进行远距离探测，具有虚警率低、灵敏度高、结构紧凑等优点。

We experimentally demonstrate third-harmonic generation (THG) in gases ionized by a femtosecond laser pulse superimposed on its second-harmonic (SH). The mechanism of THG has been investigated, and it demonstrates that a third-order nonlinear process dominates at low pump intensity. Asymmetric third-harmonic (TH) spectra are observed at different time delays in two color fields, which are attributed to the process of the four-wave mixing (FWM) of the broad spectrum of pump pulses. A joint measurement on the terahertz (THz) and the TH is performed. It reveals that the optimized phase for the THG jumps from 0 to 0.5π as the pump intensity increases, which is different from the THz being a constant, and indicates that the THG arises from the nonlinearity of the third-order bound electrons to the tunnel-ionization current.