Benefitting from narrow beam divergence, photonic crystal surface-emitting lasers are expected to play an essential role in the ever-growing fields of optical communication and light detection ranging. Lasers operating with 1.55 μm wavelengths have attracted particular attention due their minimum fiber loss high eye-safe threshold. However, interband absorption significantly decreases performance at this wavelength. Therefore, stronger feedback is needed reduce threshold thus improve output...

Enhanced external counterpulsation (EECP) treatment has been demonstrated to be effectively vasculoprotective and anti-atherosclerotic in clinical observations controlled trials. The diastolic blood flow augmentation induced by EECP greatly affected the local hemodynamic environment multiple arterial segments. In this study, a porcine model of hypercholesterolaemia was developed perform an invasive physiological measurement involving electrocardiogram, wave, pressure. Subsequently,...

Abstract Alcohols and alkenes are the most abundant commonly used organic building blocks in large-scale chemical synthesis. Herein, this is first time to report a novel operationally simple coupling reaction of vinylarenes aliphatic alcohols catalyzed by manganese presence TBHP ( tert -butyl hydroperoxide). This provides oxyalkylated products with good regioselectivity accomplishes principles step-economies. A possible mechanism has also been proposed.

To improve the passive safety of collision process, we designed a kind energy absorption device based on cutting shear rings (CSR). It can be installed in limited space, overcoming characteristic traditional devices that cannot play their advantages narrow and it will not accompanied by splashing chips process absorption. The impact characteristics outside rods are analyzed. feasibility finite element method to study device’s is demonstrated through combination drop hammer test numerical...

We present the design, fabrication, and performance of high-speed oxide-confined 1030 nm vertical-cavity surface-emitting lasers (VCSELs) with a short anti–waveguiding optical cavity. By using half-wavelength cavity to enhance limit field, anti-waveguide design increases oscillator strength, thus promoting modulation. carefully optimized multiple quantum wells doping profile in order achieve operation. The developed VCSELs exhibit modulation bandwidth exceeding 25.1 GHz at 25 °C, supporting...

A new approach was proposed and its role in improvement of the beam quality high-power broad-area diode lasers demonstrated, which a composite arrow array trench microstructure used to suppress waist tailor high order lateral modes. The shows special shrinkage with increasing injection current resulting from combined effect mode tailoring thermal lens effect. 58% parameter product realized compared conventional lasers.

Photonic-crystal surface-emitting lasers (PCSELs) have led to amazing results in overcoming the divergence limitation of semiconductor lasers. However, so far, physical mechanism behind this promising control far-field characteristics is still unclear. Here, we perform a theoretical study influence photonic crystal (PhC) geometry on far field PCSELs. The perspective from group theory adopted our analysis. We explore function symmetry formation pattern (FFP) and clarify roles played by...

Abstract High-power high-brightness broad-area diode lasers have poor lateral beam quality, which has limited the application range of this kind device. To improve a sawtooth microstructure laser was proposed and microstructures were carefully designed according to profiles each mode their dependence on self-heating induced thermal lens effect. As result selective loss adjustment, 42% improvement in quality achieved under power-maintained condition. This technology enables us develop...

A new method to improve the brightness of diode lasers based on beam-waist splitting and polarization combining was proposed demonstrated. The beam waist split by a precisely cut prism into two parts combined with combiner. advantages simple setup, high efficiency, brightness, universality were presented. slow axis M2 factor broad-area laser ridge width 180 μm reduced from 18.5 9.8, 42.4 MW cm−2 sr−1 realized; this 84.21% improvement same emitter at 8 A. commercial array spectral 9.08 4.78,...

2024年4月8日State Key Laboratory of High Power Semiconductor Lasers的TONG Haixia、WEI Zhipeng团队和State Luminescence and Applications的TONG Cunzhu团队在《发光学报》发文, 如今,人们对研究耦合腔面发射激光器结构的兴趣逐渐增加。设计的TCC ⁃VCSEL 器件只需要一个电源驱动,使其适用于高密度集成,为封装集成应用提供了新的思路。

In the present study, we report passive harmonic mode-locking (HML) of external cavity tapered semiconductor laser system with saw-toothed microstructure. The stable picosecond pulse trains were observed up to third order HML. mechanism behind was analyzed and single-pulse energy 59 pJ a repetition rate 412 MHz duration 3.9 ps realized.

It was proposed and demonstrated that a high beam quality self-pulse could be achieved by off-axis feedback for 1.95-μm GaSb-based broad-area laser. The comparative studies of on-axis were conducted in an experiment. A highly reflecting (HR) mirror with sharp edge used the system overlapping size changed moving HR mirror. At direct current 1.8 A, 45-cm external cavity length, 36% strength feedback, 1.2 mm accomplish regular periodic pulse frequency 153 MHz. M2 12.75 slow axis improved nearly...

Abstract Strong driving with light offers the potential to manipulate properties of fluoride fiber on absorbed characteristics. A 3.6 μ m continuous wave (CW) laser pumped by 1973 nm CW and 976 pulsed diode source was demonstrated in a dual-wavelength pumping (DWP) system. The output state could be changed from pulse controlling repetition frequency power pump source. By optimizing parameter, maximum 1.2 W achieved for laser. method shows new solution lasers, which can used achieve high...

We present the design, fabrication, and performance of high-speed oxide-confined 1030 nm vertical-cavity surfaceemitting lasers (VCSELs) with a short optical cavity, multiple oxide apertures. High-speed modulation was facilitated by using shortest possible cavity half-wavelength length apertures to enhance confinement fields reduce capacitance. carefully optimized quantum wells doping profile in order achieve operation. The developed VCSELs exhibit bandwidth exceeding 25.1 GHz at 25°C,...

展示了高速直接调制850 nmæ°§åŒ–ç‰©é™åˆ¶åž‚ç›´è ”é¢å‘å°„æ¿€å ‰å™¨ï¼ˆVCSEL）的结果。优化设计应变InGaAs/AlGaAsé‡å­é˜±ä»¥å®žçŽ°é«˜å¾®åˆ†å¢žç›Šï¼Œé€šè¿‡è¡¨é¢åˆ»èš€æ¥è°ƒèŠ‚å ‰å­å¯¿å‘½å®žçŽ°å“åº”å¹³å¦åŒ–ã€‚ç ”åˆ¶çš„æ°§åŒ–ç‰©å­”å¾„çº¦7 µm的VCSELå ·æœ‰å¹³å¦çš„é¢‘çŽ‡å“åº”ï¼Œ3 dB调制带宽为24 GHz，相对噪声强度值-155 dB/Hzï¼Œæœªé‡‡ç”¨ä»»ä½•é¢„åŠ é‡å’Œå‡è¡¡æŠ€æœ¯æƒ å†µä¸‹PAM4è°ƒåˆ¶æ•°æ®ä¼ è¾“é€ŸçŽ‡è¾¾80 Gb/s。