基于有效折射率法建立了窄脊型波导数值计算模型，通过实验研究了InGaAs量子阱窄脊型波导半导体激光器偏振特性与横模之间的关系。根据理论计算，脊型波导中类TM模式在慢轴方向的有效折射率差更大，类TM模式的限制因子比类TE模式的限制因子更大、更容易出现慢轴高阶模式；而随着脊型波导的高度增加，快轴高阶模式被截断，类TE₀₀模式的限制因子逐渐增加至与类TM₀₀模式相近，慢轴高阶模式因其大的散射损耗被抑制，理论上可实现高偏振度、高光束质量激光输出。在实验方面，利用量子阱材料的增益偏振特性，通过脊型高度与宽度的设计，制备了高偏振度、基横模的窄脊型波导半导体激光器。

具有半导体-金属态相变性质的二氧化钒材料可用于光电探测器的激光致盲防护。本文报道了基于磁控溅射法制备二氧化钒薄膜材料的结构、形貌特性，以及在不同温度下的光学性质。使用椭偏光谱法测量了20~100℃下可见-近红外波段二氧化钒材料的椭偏参数，利用Gaussian、Lorentz模型获取了薄膜在相变前的光学性质，结合Drude模型拟合获取了材料在相变后的光学特性，获取了材料在300~1 700 nm之间的变温折射率和消光系数等参数。变功率下1 550 nm红外激光透射率的实验测试研究表明，VO₂薄膜样品的相变阈值功率为12 W/cm²，相变前后透射率由51%减小到15%~17%，开关率69%。

We propose a joint look-up-table (LUT)-based nonlinear predistortion and digital resolution enhancement scheme to achieve high-speed and low-cost optical interconnects using low-resolution digital-to-analog converters (DACs). The LUT-based predistortion is employed to mitigate the pattern-dependent effect (PDE) of a semiconductor optical amplifier (SOA), while the digital resolution enhancer (DRE) is utilized to shape the quantization noise, lowering the requirement for the resolution of DAC. We experimentally demonstrate O-band intensity modulation and direct detection (IM/DD) transmission of 124-GBd 4 / 6-level pulse-amplitude modulation ( PAM ) -4 / 6 and 112-GBd PAM-8 signals over a 2-km standard single-mode fiber (SSMF) with 3 / 3.5 / 4-bit DACs. In the case of 40-km SSMF transmission with an SOA-based preamplifier, 124-GBd on-off-keying (OOK)/PAM-3/PAM-4 signals are successfully transmitted with 1.5 / 2 / 3-bit DACs. To the best of our knowledge, we have achieved the highest net data rates of 235.3-Gb / s PAM-4, 289.7-Gb / s PAM-6, and 294.7 Gb / s PAM-8 signals over 2-km SSMF, as well as 117.6-Gb / s OOK, 173.8-Gb / s PAM-3, and -231.8 Gb / s PAM-4 signals over 40-km SSMF, employing low-resolution DACs. The experimental results reveal that the joint LUT-based predistortion and DRE effectively mitigate the PDE and improve the signal-to-quantization noise ratio by shaping the noise. The proposed scheme can provide a powerful solution for low-cost IM/DD optical interconnects beyond 200 Gb / s.

Excitons have significant impacts on the properties of semiconductors. They exhibit significantly different properties when a direct semiconductor turns in to an indirect one by doping. Huybrecht variational method is also found to influence the study of exciton ground state energy and ground state binding energy in Al_xGa_1?xAs semiconductor spherical quantum dots. The Al_xGa_1?xAs is considered to be a direct semiconductor at Al concentration below 0.45, and an indirect one at the concentration above 0.45. With regards to the former, the ground state binding energy increases and decreases with Al concentration and eigenfrequency, respectively; however, while the ground state energy increases with Al concentration, it is marginally influenced by eigenfrequency. On the other hand, considering the latter, while the ground state binding energy increases with Al concentration, it decreases with eigenfrequency; nevertheless, the ground state energy increases both with Al concentration and eigenfrequency. Hence, for the better practical performance of the semiconductors, the properties of the excitons are suggested to vary by adjusting Al concentration and eigenfrequency

In this work, a novel one-time-programmable memory unit based on a Schottky-type p-GaN diode is proposed. During the programming process, the junction switches from a high-resistance state to a low-resistance state through Schottky junction breakdown, and the state is permanently preserved. The memory unit features a current ratio of more than 10³, a read voltage window of 6 V, a programming time of less than 10^?4 s, a stability of more than 10⁸ read cycles, and a lifetime of far more than 10 years. Besides, the fabrication of the device is fully compatible with commercial Si-based GaN process platforms, which is of great significance for the realization of low-cost read-only memory in all-GaN integration.

由于硫系玻璃具有良好的光学性质，在非线性光学等方面研究广泛，但基于硫系玻璃光电探测器的相关研究却很少。本文利用真空共热蒸发技术制备了不同掺银比例的硫系玻璃薄膜作为半导体膜层结构，并设计构建了金属-绝缘体-半导体结构的自供电光电探测器，探究了该光电探测器的响应光谱范围。结果表明，该探测器对可见光到近红外区域的光均有响应。针对掺银硫系玻璃光电探测器在635 nm波长激光下，研究了探测器响应电压与激发功率之间的关系。当激光功率小于10 mW时，探测器响应电压与激发功率线性相关；当激光功率大于10 mW时，探测器响应电压逐渐饱和。探测器的上升和衰减时间分别为3.932 s和1.522 s。本研究为硫系玻璃材料在自供电光电探测器领域的应用提供了证明。

将一个808 nm宽发射区半导体激光器应用于纵模选择束腰劈裂偏振合束外腔中，实现了高光束质量、高亮度和窄线宽的激光输出。所获激光输出功率为5.08 W，快慢轴光束质量M²=1.85×18.2，慢轴光束质量较自由运转激光器提高48%，输出激光亮度B=22.74 MW·cm^-2·sr^-1，是原激光器自由运转的1.3倍。所获激光光谱线宽为0.47 nm，压缩至原激光器自由运转的光谱宽度的0.14。