Pulse-front matched ultra-broadband optical parametric chirped pulse amplifier for sub-12 fs pulse generation

We propose a LBO-based ultra-broadband chirped pulse optical parametric amplifier employing pulse-front-matching to yield transform-limited sub-12-fs pulses. Measurement of the maximum possible gain bandwidth for the LBO-based OPCPA demonstrates more than 60nm gain bandwidth FWHM. For the generation of TL pulses by the use of this OPCPA, a suitable combination of OPCPA and PFM is first presented. The PFM pump geometry realizes tilt-free signal amplification, and permits this OPCPA to generate TL sub-12-fs pulses.

MS/RF CMOS工艺兼容的光电探测器模拟与测试

设计了一种新型的与MS/RF CMOS工艺全兼容、带深n阱(DNW)、浅沟槽隔离(STI)的双光电探测器,分析了其工作机理,用器件模拟软件ATLAS对其暗电流、响应电流、光调制频率响应和波长响应进行了模拟.采用TSMC 0.18 μm MS/RF CMOS工艺进行了流片,对芯片进行了暗电流和响应度的测试.模拟和测试结果均表明,该探测器与常规双光电探测器相比,具有较低的暗电流和较高的响应度.

Comparative studies of semiconductor saturable absorber mirror mode-locking dynamics in pulsed diode-end-pumped picosecond Nd:GdVO4 and Nd:YAG lasers

Ultrashort pulses were generated in passively mode-locked Nd:YAG and Nd:GdVO4 lasers pumped by a pulsed laser diode with 10-Hz repetition rate. Stable mode-locked pulse trains were produced with the pulse width of 10 ps. The evolution of the mode-locked pulse was observed in the experiment and was discussed in detail. Comparing the pulse evolutions of Nd:YAG and Nd:GdVO4 lasers, we found that the buildup time of the steady-state mode-locking with semiconductor saturable absorber mirrors (SESAMs) was relevant to the upper-state lifetime and the emission cross-section of the gain medium.

Layout Design and Optimization of RF Spiral Inductors on Silicon Substrate

The effects of key geometrical parameters on the performance of integrated spiral inductors are investigated with the 3D electromagnetic simulator HFSS. While varying geometrical parameters such as the number of turns （N）,the width of the metal traces （W）,the spacing between the traces （S）,and the inner diameter （ID）, changes in the performance of the inductors are analyzed in detail. The reasons for these changes in performance are presented. Simulation results indicate that the performance of an integrated spiral inductor can be improved by optimizing its layout. Some design rules are summarized.

蓝宝石衬底上单晶InAlGaN外延膜的RF-MBE生长

利用射频等离子体辅助分子束外延技术在蓝宝石衬底上外延了晶体质量较好的单晶InAlGaN薄膜．在生长InAlGaN外延层时，获得了外延膜的二维生长，卢瑟福背散射测量结果表明，InAlGaN外延层中In，Al和Ga的组分分别为2％，22％和76％，并且元素的深度分布比较均匀，InAlGaN（0002）三晶X射线衍射摇摆曲线的半高宽为4．8′，通过原子力显微镜观察外延膜表面存在小山丘状的突起和一些小坑，测量得到外延膜表面的均方根粗糙度为2．2nm．利用光电导谱测量InAlGaN的带隙为3．76eV．

Monolithically Integrated Optoelectronic Receivers Implemented in 0. 25μm MS/RF CMOS

A monolithically integrated optoelectronic receiver is presented. A silicon-based photo-diode and receiver circuits are integrated on identical substrates in order to eliminate the parasitics induced by hybrid packaging. Implemented in the present deep sub-micron MS/RF （mixed signal, radio frequency） CMOS,this monolithically OEIC takes advantage of several new features to improve the performance of the photo-diode and eventually the whole OEIC.

MS／RF CMOS工艺兼容的光电探测器

为实现光纤通信系统中的单片光电集成，采用工业标准工艺设计了硅基光电探测器，讨论了光电探测器的机理，提出了五种新的探测器结构，并采用TSMC0．18μmMS／RF CMOS工艺进行了流片．利用半导体测试仪对芯片进行了测试，包括探测器的暗电流、响应度和结电容，并分析了深n阱、浅沟槽隔离等工艺步骤对探测器参数的影响．结果表明，利用标准MS／RF CMOS工艺实现的光电探测器具有良好的特性。

蓝宝石衬底上单晶InN外延膜的RF-MBE生长

采用低温氮化铟(InN)缓冲层，利用射频等离子体辅助分子束外延(RF-MBE)方法在蓝宝石衬底上获得了晶体质量较好的单晶InN外延膜．用光学显微镜观察所外延的InN单晶薄膜，表面无铟滴．InN(0002)双晶X射线衍射摇摆曲线的半高宽为14′；用原子力显微镜测得的表面平均粗糙度为3．3nm；Hall测量表明InN外延膜的室温背景电子浓度为3．3×10^18cm^3，相应的电子迁移率为262cm^2／(V·s)．

RF-MBE Grown AlGaN/GaN HEMT Structure with High Al Content

A Si doped AlGaN/GaN HEMT structure with high Al content (x= 44%) in the barrier layer is grown on sapphire substrate by RF-MBE. The structural and electrical properties of the heterostructure are investigated by the triple axis X-ray diffraction and Van der Pauw-Hall measurement, respectively. The observed prominent Bragg peaks of the GaN and AlGaN and the Hall results show that the structure is of high quality with smooth interface.fabricated and characterized. Better DC characteristics, maximum drain current of 1.0A/mm and extrinsic transconductance of 218mS/mm are obtained when compared with HEMTs fabricated using structures with lower Al mole fraction in the AlGaN barrier layer. The results suggest that the high Al content in the AlGaN barrier layer is promising in improving material electrical properties and device performance.

Passively Mode Locked Diode-End-Pumped Yb∶YAB Laser with High Reflectivity Type Semiconductor Saturable Absorption Mirror

利用金属有机气相淀积方法生长了一种新型吸收体:高反射率半导体可饱和吸收镜.用这种吸收体兼作端镜,实现了1.044μm半导体端面泵浦Yb∶YAB激光器被动锁模,脉冲宽度为3.05ps,重复率为375MHz,输出功率为45mW.

Passively Mode Locked Diode-End-Pumped Nd∶YAG Laser with In0.25 Ga0.75 As as Output Coupler

A novel InGaAs(LT-In0.25 Ga0.75 As) absorber grown by metal organic chemical vapor deposition at low temperature is presented.Using it as well as an output coupler,passive mode locking,which produces pulses as short as several hundred picoseconds for diode-end-pumped Nd∶YAG laser at 1.06μm,is realized.The pulse frequency is 150MHz.