二维光子晶体对耦合波导激光器侧模的调制研究

利用光子晶体的自准直效应来调制耦合波导激光器的侧模,并用时域有限差分（FDTD）方法对五通道和九通道耦合波导激光器进行仿真,成功改变了模式的传播方向,使得相邻光场之间的相位差从兀变为零。在两种耦合波导结构中分别获得了远场发散角为12°和7°的单峰,既兼顾了激光器的稳定性,又得到了高质量的光束。     

Dark blue erenkov second harmonic generation in the two-layer-stacked hexagonal periodically poled MgO:LiNbO_3s

We report the dark blue nonlinearˇCerenkov radiation by the second harmonic generation(SHG)in a two-layer-stacked hexagonal periodically-poled-MgO:LiNbO3s(PPMgOLNs).Based on the direct wafer bonding of two target PPMgOLNs rotating around the axis perpendicular to the plane with an angle of 30°,twelve bright spots as twice of those in a single PPMgOLN are shown at each second-harmonicˇCerenkov ring.The experimental results agree with the theoretical ones and present a promising application in the fabrication of three-dimensional(3D)PPMgOLNs.     

椭圆氧化孔径垂直腔面发射激光器的偏振特性

为了改善用于铷原子钟的795 nm垂直腔面发射激光器（VCSEL）的偏振稳定性,研究了不同氧化孔径和椭圆度对VCSEL偏振性能的影响。利用COMSOL Multiphysics的波动光学频域模块模拟了不同氧化孔径对有源区谐振光强的影响。结果表明,当氧化孔径为3.5～4.0μm时,有源区的谐振强度最高。采用可实时观察的湿法氧化系统,研究了氧化温度对氧化速率和氧化孔椭圆度的影响。随着注入电流的增加,三种不同椭圆氧化孔的VCSEL表现出不同的模式特性、偏振特性和偏振角旋转特性。测试结果表明,带有长轴径为3.7μm、椭圆度为1.7的椭圆氧化孔的VCSEL性能最佳。在85℃下,当注入电流为1.5 mA时,输出功率为0.86 mW,激光波长为795.4 nm,边模抑制比（SMSR）为43 dB,线宽为65 MHz,正交偏振抑制比（OPSR）为23.8 dB。在0.6～2.7 mA的范围内,VCSEL的主偏振方向保持不变。     

High peak power density and low mechanical stress photonic-band-crystal diode laser array based on non-soldered packaging technology

A high peak power density and low mechanical stress photonic-band-crystal(PBC) diode laser array based on non-soldered packaging technology is demonstrated. The array consists of the PBC diode laser bars with small fast axis divergence angles. Meanwhile, we design the non-soldered array structure that realizes mechanical stacking of 10 bars in the vertical direction. In the experiment, the peak power density of the PBC array is about 1.75 times that of the conventional array when the same total ...     

超低阈值横向腔光子晶体面发射激光器

首次在无DBR结构的商业外延波导晶片上实现了电泵横向腔光子晶体面发射激光器(LC-PCSEL)。深孔刻蚀技术使光子晶体深达2.6μm,穿透有源区,对有源区的模式直接调制。通过较小区域的光子晶体与FP腔的融合集成,利用带边模式Γ2-1的横向振荡垂直输出特性,室温下获得了1553.8 nm的面发射激光,线宽0.4 nm。超低阈值电流密度为667 A/cm2,纵向和横向的远场发散角分别为7.5°和5.5°。LC-PCSEL的设计为电注入面发射激光器的研制提供了新的思路,为该类激光器的批量生产提供了可能。     

Improving the performance of high-power broad-area lasers by suppressing cavity modes propagating in the lateral dimension

We first study the effect of cavity modes propagating in the lateral dimension on high-power semiconductor lasers with a large stripe width. A sidewall microstructure was fabricated to prevent optical feedback of lateral resonant modes.Theoretically, we demonstrate the existence of lateral resonant modes in the Fabry–Perot cavity with a large stripe width.Experimentally, we design the corresponding devices and compare them with conventional broad-area diode lasers. About a 15% reduction in thres...     

高功率1060 nm垂直腔面发射激光器

为了提高1060 nm垂直腔面发射激光器（VCSEL）的性能,本文对大功率1060 nm VCSEL进行了理论模拟和实验研究。计算得到红移速度为0.40 nm/K,据此确定增益和腔模失配量为-20 nm。对比分析了6种不同InGaAs组分和厚度的量子阱,以及3种不同势垒材料的增益特性和输出特性,模拟结果表明,应变补偿的InGaAs/GaAsP量子阱有源区在温度稳定性、阈值电流以及功率方面更有优势。对P型分布式布拉格反射镜（DBR）进行优化设计,优化DBR渐变层厚度和对数,有助于获得更好的输出特性。采用金属有机化学气相沉积生长了InGaAs/GaAsP应变补偿量子阱结构的VCSEL外延片,并制备了单管和阵列VCSEL,实验数据和理论分析基本吻合。实验测得,288单元VCSEL阵列在4.5 A电流下,连续输出功率为2.62 W,最高电光转换效率为36.8%,5 mm×5 mm VCSEL阵列准连续条件下（脉宽为100μs,占空比为1%）,且在100 A电流下,获得峰值功率为53.4 W。     

High-Brightness Low-Divergence Tapered Lasers with a Narrow Taper Angle

High-brightness tapered lasers with photonic crystal structures are designed and fabricated.A narrow taper angle is designed for the tapered section.The device delivers an output power of 3.3 W and a maximum wall-plug efficiency of 43%.The vertical beam divergence is around 110 at different currents.Nearly diffraction-limited beam qualities for the vertical and lateral directions are obtained.The lateral beam quality factor M~2 is below 2.5 and the vertical M~2 value is around 1.5 across the whole operating current range.The maximum brightness is 85 MW·cm~(-2)sr~(-1).When the current is above 3.3 A,the brightness is still above 80 MW·cm~(-2)sr~(-1).     

新型亚波长光栅横向腔面发射激光器

本文报道一种新型的横向腔面发射激光器,基于亚波长光栅平面内的横向谐振与垂直发射。器件采用不含DBR结构的商用波导外延材料,不需要晶片键合技术。在1552.44 nm处获得了23.0 dB的边模抑制比,最高输出功率5.32 mW。此单模激射与带边模式计算相吻合。在3维的模拟中,我们观察到光栅表面的光输出。