GaAs压电物性的研究

较详细地讨论了GaAs压电效应的起源。有3种不同的机制对压电效应有贡献.这些机制是离子电荷的内部位移、电子电荷的内部位移和由于应变引起的离子性的变化.推导出了任意晶体取向压电常数张量的表达式,证明了,对正应力而言,GaAs〈111〉方向有最强压电效应发生,且Ga原子呈负电性,而As原子则呈正电性.

A STUDY OF THE PIEZOELECTRIC PROPERTIES OF GaAs

The origin of the piezoelectric effect of GaAs is discussed in some detail.TheGa atoms are negatively charged and As atoms positively charged.The piezoelectric con-stant tensors for arbitrarily oriented GaAs have been obtained.It is verified that for nor-mal stress when the GaAs samples are oriented in the 〈111〉 direction the maximumpiezoelectric effect occurs.As far as the piezoelectric properties and fabrication technologyare concerned,〈100〉 oriented GaAs substratcs are fit for the force sensors.

Optimizing the design of GaAs/AlGaAs thin-film waveguides for integrated mid-infrared sensors

Optical simulations of GaAs/AlGaAs thin-film waveguides were performed for investigating the dependence of the modal behavior on waveguide geometry and the resulting analytical sensitivity. Simulations were performed for two distinct mid-infrared wavelengths, thereby demonstrating the necessity of individually designed waveguide structures for each spectral regime of interest. Hence, the modal behavior, sensitivity, and intensity of the evanescent field were investigated via modeling studies at 1600 and 1000 cm^(-1), thereby confirming the utility of such simulations for designing mid-infrared sensors based on thin-film waveguide technology.

GaAs霍尔开关集成电路的研制

成功地设计并制造出GaAsMESFET霍尔开关集成电路。该电路采用了方形霍尔元件,绝对灵敏度为704mV/T;信号处理电路由差分放大电路和触发电路组成,触发电路结构类似于SCFL的D触发器。结果表明,开关性能良好,工作点合理,达到设计要求。实验结果还表明,霍尔元件和放大电路可构成灵敏度很高的霍尔线性集成电路。