美国实现第一个硅激光器

美国加利福尼亚大学已演示了据称第一个利用喇曼效应的硅（Si）激光器。这种发射波长为1675nm、具有25MHz重复频率时脉冲喇曼激光器采用硅波导作为增益介质，关键器件是硅上隔离的凸台波导和环绕该芯片的环形光纤。在9W峰值泵浦脉冲功率下获得激光阈值，并获得8．5％的斜效率。     

硅基喇曼激光器研究进展(本期优秀论文)

硅基激光器的研制对于新兴的硅基光子学的发展具有重要意义,介绍了硅基材料中喇曼散射的原理、特点,并总结了硅基喇曼激光器的发展历程和最新进展,展示了硅基喇曼激光器发展的良好前景.     

1455nm光纤喇曼激光器研究

研制完成了以掺锗光纤作喇曼增益介质、光纤布喇格光栅作谐振腔镜的1455nm光纤喇曼激光器.在1100nm抽运光的作用下,实现了五阶喇曼频移,并在1455nm波长处获得597mW的稳定激光输出,光光转换效率约为6.35%.     

美国实现第一个硅激光器

美国加利福尼亚大学已演示了据称第一个利用喇曼效 应的硅(Si)激光器。这种发射波长为1675 nm、具有25 MHz重复频率的脉冲喇曼激光器采用硅波导作为增益介 质,关键器件是硅上隔离的凸台波导和环绕该芯片的环形 光纤。在9 W峰值泵浦脉冲功率下获得激光阈值,并获得 8．5％的斜效率。     

一种红外激光位相推迟器

光波位相推迟器也称为波片,将线偏振光转换为圆偏振光的称四分之一波片.用于紫外、可见波段的波片已有商品,但是,适用于中红外波段的相应元件国内至今未见报道过.P.Rabinowtz和A.Kaldor等人曾报道用硒化锌多晶制作棱镜式中红外波段的1/4波片,用于产生16μm波长的受激氢喇曼激光系统中增加散射截面、提高喇曼增益系数、降低阈值.可是,现在国内还不能生长适合作棱镜的大块优质ZnSe材料.近年来,在现有工业二氧化碳激光器上附加一     

光纤喇曼激光器及多波长输出的分析

为了优化设计光纤喇曼激光器的各项参数,采用喇曼激光器的基本理论模型模拟分析了用DCF光纤做增益介质的光纤喇曼激光器的输出特性,提供了激光器优化设计的方法;通过改变光纤的长度和输出端面的耦合效率得到最优的激光输出;以及改变泵浦功率时输出激光功率的变化情况;并进一步分析了多波长的光纤激光器,得到四波长输出的光纤激光器。     

微结构光纤激光器件

由于微结构光纤灵活多变的结构特点,使得以其为增益介质的光纤激光器件,具有比普通光纤激光器件更加优异的性能.本文结合国际上微结构光纤激光器件的最新研究进展情况,概述了微结构光纤作为增益介质的独特特性、微结构光纤激光器件的理论分析方法和掺铒、掺镱以及喇曼微结构光纤激光器件的特点.     

喇曼光纤激光器最新进展

喇曼光纤激光器以其众多的优良特性在光通信、光传感以及视觉安全雷达、激光光谱和激光医学等领域有 广阔的发展前景。综合报道了近年来喇曼光纤激光器的最新研究进展,并对几种新型激光器进行了分析。     

固体自喇曼黄光激光器研究进展

黄光激光作为激光研究领域的一大热点,取得了丰硕的研究成果及广泛的应用。随着可同时作为激光晶体和喇曼晶体的自喇曼晶体的发展,逐渐掀起了自喇曼黄光激光器的研究热潮。总结归纳了近10年来固体自喇曼黄光激光器的研究进展。按激光器的工作方式将其分成连续式和脉冲式激光器,通过分类比较不同工作方式的激光器各自的优缺点,明确了自喇曼黄光激光器今后的研究趋势是多方法并用。结构紧凑、低阈值等特点使其在生物医疗领域拥有巨大的应用潜力。以后的研究重点更偏向于高转换率、高稳定性、低成本及小型化。该研究报告为后续研究方向提供了参考。     

用途广泛的硅激光器

按照常规,人们认为硅材料是不能成为制作激光器的材料,这是因为它是一种间接带隙半导体.然而,Intel公司最近采用标准的互补型金属氧化半导体(CMOS)技术成功制造出硅波导,并首次验证了基于受激喇曼散射的连续波硅光学放大器和激光器.此项研究成果不仅表明了硅材料可以用作光放大和产生激光的光子材料,而且标志着这一成果是向在单一硅基底上单片集成电子和光子线路发展的里程碑.     

Anodic nitridation of silicon and silicon dioxide

Anodic nitridation of Si wafers and SiO2films in an ammonia plasma was investigated. Compositions of the anodic nitride and the anodic nitrided-oxide films were analyzed with Auger electron spectroscopy and Rutherford backscattering techniques. The etching and oxidation behavior as well as the interfacial, electrical conduction, and charge trapping properties were studied.     

Amorphous silicon/silicon carbide superlattice avalanchephotodiodes

An a-Si/SiC:H superlattice avalanche photodiode (SAPD) has been successfully fabricated on an ITO/glass substrate by plasma-enhanced chemical vapor deposition. The room-temperature electron and hole impact ionization rates, α and β, have been determined for the a-Si/SiC:H superlattice structure by photocurrent multiplication measurements. The ratio α/β is 6.5 at a maximum electric field of 2.08×10⁵ V/cm. Avalanche multiplications in the superlattice layer yields an optical gain of 184 at a reverse bias V_R=20 V and an incident light power P_in=5 μW. An LED-SAPD photocouple exhibited a switching time of 4.5 μs at a load resistance R-1.8 kΩ     

The silicon solution [silicon photonics]

As newer, faster microprocessors roll out, the copper connections that feed those processors within computers and servers will prove inadequate to handle huge amounts of data. To address this concern, this paper proposes the replacement of the copper with optical fiber and the electrons with photons. Called silicon photonics, this technology will allow manufacturers to build optical components using the same semiconductor equipment and methods they use now for ordinary integrated circuits. This would dramatically lower the cost of photonics while significantly improving performance.     

Hot-electron emission from silicon into silicon dioxide

Recent progress in the study of hot-electron emission from silicon into silicon dioxide is discussed. Experimental techniques include avalanche injection using gated diodes and MOS capacitors, nonavalanche injection using IGFET structures with an underlying supply p - n junction, and optically induced injection using silicon-gate IGFET structures. IGFET structures allow the fields in the SiO₂ layer and in the silicon depletion region to be varied independently. In addition, IGFET structures of reentrant geometry allow absolute emission probabilities of the hot electrons to be determined. Such absolute emission characteristics are useful not only for designing silicon devices but also for quantitative testing of theoretical models of the emission process. Several mechanisms of importance in the emission process have been identified. These are the Schottky lowering of the emission barrier, the scattering of hot electrons in the image-force potential well in the SiO₂ layer, the tunneling of hot electrons, and the effect of lattice temperature on electron heating. There is also experimental evidence of the dependence of the hot-electron distribution on electric field gradient. At present, only phenomenological models based on the lucky-electron concept have been developed to the point where quantitative comparison with experimental results is possible. The essential features of these models are discussed.     

Polycrystalline silicon solar cells on metallurgical silicon substrates

The use of a polycrystalline silicon p-n junction structure deposited on low-cost substrates is a promising approach for the fabrication of low-cost solar cells. Metallurgical-grade silicon, with a purity of about 98% and a cost of about $1/kg, was cast into plates in a boron nitride container and used as substrates for the deposition of solar cell structures. The substrates were polycrystalline with millimeter size crystallites. Solar cells of the configurations n>⁺-silicon/p-silicon/metallurgical silicon and n⁺-silicon/p⁺-silicon/metallurgical silicon were prepared by the thermal decomposition of silane and the thermal reduction of trichlorosilane containing appropriate dopants. The AMO efficiencies of n⁺-silicon/p-silicon/metallurgical silicon solar cells were up to 2.8% (with no anti-reflection coatings) and were limited by the grain boundaries in the p-layer. The grain boundary effects were reduced by increasing the dopant concentration in the p-layer, and AMO efficiencies of about 3.5% were obtained from n⁺-silicon/p⁺-silicon/metallurgi silicon solar cells.     

Czochralski silicon

When silicon technology was new there were effects and observations which went unused or unrecognized in the rush to get products to market. This paper covers one such set of observations in silicon crystal growth. It has been abstracted from a historical perspective of silicon processing being compiled for family and associates from the experiences of the author.     

Beyond the silicon roadmap [silicon laser cooling]

We have first developed an all-solid-state 252 nm coherent light source for laser cooling of silicon atoms. This can give an impetus to research into the manipulation of the atomic motion of silicon atoms toward nanoprocess applications. Therefore, we developed an experimental setup for silicon atom manipulation. It was found that a high-quality silicon atomic beam, useful for nanoprocess applications, is obtainable with manipulation using the coherent light source in the system. With this unique apparatus, we continue the challenge to demonstrate the spatial design of nuclear spins of the family of isotopes with laser cooling of Si.     

REQUIREMENT OF SILICON FLATNESS FOR SILICON DIRECT BONDING TECHNOLOGY

The influence of silicon slice flatness on bonding technology and the relation between a foreign particle and resulting bubble are quantitatively presented by the elastic theory. It is demonstrated experimentally by X-ray double crystal diffractometry and infrared imager.     

Microlens fabricated in silicon on insulator using porous silicon

In order to realize the planar gradient refractive index (GRIN) microlens which is based upon porous silicon (PSi) and fabricated on silicon on insulator (SOI), a novel anodization method is used by applying lateral electric field. The microlens with smooth variation of the effective optical thickness is achieved. The lens is transparent in the infrared region, including the optical communication window (1.3 μm<λ<1.6 μm). This approach also allows the fabrication of an array of such lenses on SOI, and the GRIN microlens can be used as potential components in future silicon-based integrated optical circuits.     

Charge trapping in ion-sputtered silicon dioxide films on silicon

Charge trapping in thermal silicon dioxide has been previously studied in great detail. Recently there has been an interest in depositing silicon dioxide films at lower temperatures to be compatible with device technologies that are not compatible with the higher temperature. This paper discusses the electron and hole trapping behavior in room temperature, ion-sputtered silicon dioxide thin films. Generally, these films are observed to trap both carriers much more efficiently then thermal silicon dioxide films. The trapping parameters such as the trap cross-section, location, density and the trapping efficiency are reported.