Micromachined bolometer with single-crystal silicon diode as temperature sensor

An infrared-sensitive micromachined bolometer integrated with a single-crystal silicon diode as temperature sensor was designed and fabricated. An island of single-crystal silicon containing the diode underneath the bolometer membrane was centered and thermally isolated from the substrate. Diode temperature sensitivity biased by constant current was found to be -2.6 mVK/sup -1/ and bolometer thermal conductivity of 2.0/spl times/10/sup -7/ WK/sup -1/. Due to its negligible self-heating effect, the bolometer could be biased permanently and its output signal integrated for an unlimited time. The utilization of diode-based bolometer as focal plane array basic block is discussed.     

High-temperature(T = 80℃) operation of a 2μm InGaSb-AlGaAsSb quantum well laser

正An InGaSb/AIGaAsSb compressively strained quantum well laser emitting at 2μm has been fabricated. An output power of 82.2 mW was obtained in continuous wave(CW) mode at room temperature.The laser can operate at high temperature(T = 80℃),with a maximum output power of 63.7 mW in CW mode.     

基于单片机的大棚温湿度控制系统设计

针对研究蔬菜大棚智能温湿度控制,设计了一种基于计算机自动控制的智能蔬菜大棚温湿度控制系统。详细阐述了该系统的温湿度采集、温湿度显示、控制系统等系统软硬件的设计思想,以DS18820和HM1500LF作为温湿度传感器,以AT89S52单片机为系统核心,最后利用DELPHI软件进行系统仿真。该研究设计的蔬菜大棚智能温湿度控制系统人机界面良好,操作简单方便,自动化程度高,造价低廉,具有良好的应用前景和推广价值。     

Metallic Magnetic Calorimeters for X-Ray Spectroscopy

An increasing number of experiments employ low-temperature radiation/particle detectors which are based on a calorimetric detection scheme and operate at temperatures below 100 mK. Metallic magnetic calorimeters use a metallic paramagnetic temperature sensor in tight thermal contact with the X-ray absorber. The magnetization of the sensor is used to monitor the temperature change of the detector upon the absorption of single photons, which is proportional to the absorbed energy. Low-noise high-bandwidth dc superconducting quantum interference devices read out the small changes in magnetization. An energy resolution of DeltaE _FWHM = 2.7 eV was obtained for X-ray energies up to 6 keV.     

A Highly Stabilized MIC Gunn Oscillator Using a Dielectric Resonator

An X-band frequency-stabilized MIC Gunn oscillator of a very simple structure using a dielectric resonator is developed. It is studied how the oscillating characteristics can be controlled by circuit parameters, with special attention to the factors affecting the frequency stability with temperature. By optimizing these factors and by selecting the proper temperature coefficient of a newly developed dielectric resonator, the high frequency stability of less than /spl plusmn/100 MHz over the temperature range from -20 to 60/spl deg/C (2x10 /sup -7/ / /spl deg/C) was obtained.     

分子束外延CdTe（211）B／Si复合衬底材料

报道了用MBE的方法，在3英寸Si衬底上制备ZnTe／CdTe（211）B复合衬底材料的初步研究结果，该研究结果将能够直接应用于大面积Si基HgCdTe IRFPA材料的生长．经过Si（211）衬底低温表面处理、ZnTe低温成核、高温退火、高温ZnTe、CdTe层的生长研究，用MBE方法成功地获得了3英寸Si基ZnTe／CdTe（211）B复合衬底材料．CdTe厚度大于10μm，XRD FWHM平均值为120arc sec，最好达到100arc sec，无（133）孪晶和其他多晶晶向．     

The effect of different bonding temperatures on the mechanical and electrical performance of NCF-bonded flip-chip-on-flex packages

Liquid crystal displays (LCDs) and organic light emitting diodes (OLEDs) are the technology involved in electronic displays in order to get a better viewing angle and high-density resolution products. Fine-pitch, flip-chip interconnection is one method which is able to enhance the display performance with high color resolution. Nonconducting film (NCF) is a novel material developed for fine-pitch applications. This study investigates the temperature effect on the electrical contact performance of an NCF-bonded chip-on-flexible (COF) substrate package. The changes in contact resistance after reflow at a peak temperature of 260/spl deg/C for three times were measured with a four-point probe method. The bonding temperature has a significant effect on the peel strength of the NCF-bonded COF. A high peel strength for the NCF COF bonded at a high temperature indicated that the NCF obtained sufficient mechanical strength to hold the interconnection joints. A low bonding temperature is preferable to obtain good electrical contact, but sufficient high temperature is needed to ensure a good mechanical and reliable joint. An excessively high bonding temperature is to be avoided because it gives instant curing at the contact point which restricts good electrical conduction. An NCF with a curing degree of /spl sim/86% was needed to ensure sufficient and reliable electrical joints in the COF.     

A column-base InP lateral bipolar transistor

An InP lateral bipolar transistor has been successfully fabricated on a semi-insulating substrate by implanting Si⁺ as the emitter and collector contacts and Mg⁺ as the column base. An array of 33 1-μm-diameter columns with 1-μm separation between each was formed between the emitter-collector spacing of 3 μm. A current gain of 290 was obtained at 77 K; it was over 12 at room temperature     

Experimental demonstration of a buried-channel charge-coupleddevice in 6H silicon carbide

Fundamental operation of the first buried-channel charge-coupled device (BCCD) in 6H-SiC is presented. The n-type buried-channel was formed by ion implantation of nitrogen, and a double level overlapping-polysilicon-gate process was adapted to the SiC MOS system. An electron mobility of 200 cm²/Vs was measured in the channel, which is doped 1.6×10¹⁷ cm^-3. An eight-stage, four-phase BCCD shift register was operated in the pseudo-two-phase configuration at room temperature. At 5.5 kHz, the charge transfer efficiency is greater than 99.4%     

An on-chip temperature sensor by utilizing a MOS tunneling diode

A simple metal-oxide-semiconductor (MOS) tunneling diode was demonstrated for application to an integrated temperature sensor. The MOS diode equipped with a 21-Å oxide was biased inversely at 1.8 V to monitor its substrate temperature through gate current. The gate current increased more than 700 times when the diode was heated from 20 to 110°C. An exponential fitting curve correlated the gate current and the substrate temperature. Moreover, characteristics of the diode were analyzed though C-V and I_{1.8 V}-n_i curves. The good temperature response of the MOS tunneling diode might be useful in self-diagnosis or self-protection IC applications     

The Importance of Accurate Skin Temperature in Assimilating Radiances From Satellite Sounding Instruments

An error analysis has been performed, which shows that skin temperature errors are important for sounding channels. An approach for estimating skin temperature and emissivity errors from the dependence of differences between observed and calculated radiances on surface-to-space transmittance is described. Estimates of emissivity and skin temperature error for the operational Met Office data assimilation system are presented as an example, and the implications are discussed, in terms of use of data over different surfaces and in different conditions (e.g., day/night). The results highlight the need for a better emissivity estimate over sea ice than that used at the Met Office and the inaccuracy of the land surface skin temperature that was derived from radiative flux balance at the surface.     

一种用于音频Σ-ΔA/D转换器的CMOS带隙电压基准源

在传统带隙基准电压源电路结构的基础上,通过在运放中引入增益提高级,实现了一种用于音频Σ-ΔA/D转换器的CMOS带隙电压基准源。在一阶温度补偿下实现了较高的电源抑制比(PSRR)和较低的温度系数。该电路采用SIMC 0.18-μm CMOS工艺实现。利用Cadence/Spectre仿真器进行仿真,结果表明,在1.8 V电源电压下,-40～125℃范围内,温度系数为9.699 ppm/℃;在27℃下,10 Hz时电源抑制比为90.2 dB,20 kHz时为74.97 dB。     

Reduced Temperature Dependence of Lasing Wavelength in Membrane Buried Heterostructure DFB Lasers With Polymer Cladding Layers

An athermal operation of the lasing wavelength in a membrane buried heterostructure distributed feedback (BH-DFB) laser was demonstrated by adopting a polymer (benzocyclobutene) cladding layer which has a negative temperature coefficient of refractive index. Membrane BH-DFB lasers of core thickness 65 nm were operated under room-temperature continuous-wave conditions. The temperature dependence of the lasing wavelength was measured to be 2.45times10^-2 nm/degC, which is about 20%-30% of that for conventional semiconductor lasers     

Externally heated copper vapor laser for parametric studies

The construction and operation of a reliable externally heated copper vapor laser for parametric studies is presented. A long-life high-temperature heating element is described. A temperature measurement method has been developed that is compatible with laser operation and has an accuracy ofpm20degC over the range0-1700degC. The laser is operated in the burst mode to eliminate effects of discharge hearing and enable measurement of the time evolution of laser behavior. An electrical circuit was developed which eliminates transient electrical behavior at the beginning of the burst. An example of parameter measurement, the dependence of output power on tube temperature under specific operating conditions, is also given.     

Room temperature unpassivated InAs p-i-n photodetectors grown bymolecular beam epitaxy

An unpassivated InAs p-i-n photodetector with excellent performance at room temperature was demonstrated. The zero-bias resistance area products of the diode with 720-nm thick i-layer are 8.1 Ω-cm² at room temperature and as high as 1.3 M Ω-cm² at 77 K. At 77 K, the diode exhibits a breakdown voltage exceeding 13 V. When tested under a 500 K blackbody source, the measured detectivity limited by Johnson noise is 1.2×10¹⁰ cm-Hz^½/W at room temperature and 8.1×10 ¹¹ cm-Hz^½/W at 77 K. To our knowledge, this is the best data for a room temperature infrared detector     

A monolithic GaInAsN vertical-cavity surface-emitting laser for the 1.3-/spl mu/m regime

An all-epitaxial GaInAsN vertical-cavity surface-emitting laser for room-temperature (RT) emission at 1.3 /spl mu/m was developed by solid-source molecular beam epitaxy using a plasma source for nitrogen activation. RT photopumped operation is demonstrated at a wavelength of 1283 nm. Stimulated emission was observed up to a record high temperature of 143/spl deg/C, resulting in an emission wavelength of 1294 nm.     

Double-active-layer index-guided InGaAsP-InP laser diode

A buried crescent InGaAsP-InP laser with two active layers was fabricated to study the temperature behavior of the double-carrier-confinement structure. An anomalously high characteristic temperature T₀ was measured, and optical switching behavior was observed. A mode analysis and numerical calculation using a rate equation approach explained qualitatively very well the experimental results. It was revealed that both the Auger recombination in this special double-active-layer configuration and the temperature-dependent leakage current, which leads to uniform carrier distribution in both active regions, are essential to increase T₀     

Three-terminal bistable low-threshold strained InGaAs/GaAs lasergrown on structured substrates for digital modulation

Strained InGaAs/GaAs quantum-well three-terminal lasers with monolithically integrated intracavity modulators were fabricated using low threshold current structures formed by the temperature engineered growth (TEG) technique. An on-off switching ratio of 556 was obtained for a 30-mV change in absorber voltage. An optical power contrast ratio of 7.5 was measured with a total DC power consumption of 25.3 mW. These results show a great improvement in the digital (on-off) switching performance of three-terminal lasers with intracavity modulators     

基于RS-485通信的温度水位远程测控系统

为满足太阳能热水工程远距离测控的需要,设计了一个基于单片机控制的温度和水位远程测控系统。系统的主机和从机均以ATmega16为控制器,二者通过RS-485通信,距离可以超过1 km。用NTC热敏电阻作测温元件,使用单片机内置的10位A/D转换模块实现多路温度的测量。通过非对称式多谐振荡器电路把水位转换为振荡频率,再用计数器测量频率来实现水位的测量。给出了主机和从机的完整电路及功能,较详细地介绍了水位和温度的测量电路以及传感器参数。     

半花菁LB多层膜二次谐波产生的温度特性研究

利用吸收谱和二次谐波产生 (SHG)技术研究了温度对半花菁Langmuir Blodgett(LB)多层膜的膜结构和非线性光学特性的影响。LB膜的二次谐波强度起初随温度的增加而增加 ,最大值约在 45℃左右 ,然后随温度的增加而减小。在半花菁与花生酸或花生酸铬交替的LB多层膜中 ,由于花生酸的融化 ,导致膜结构的变化 ,使得二次谐波强度随温度的变化有一个突变点。线性吸收谱表明半花菁分子在LB多层膜中形成了H 聚集体 ,并且通过加热可以使聚集体分解