排序方式: 共有11条查询结果,搜索用时 250 毫秒
1.
2.
A unusual electrochromism is observed in amber cubic boron nitride (cBN) single crystals when breakdown possibly related to impurities and defects occurs. The electrochromism induces an abrupt increase in the absorption coefficient of the cBN crystals within the visible and infrared region. The change of the absorption coefficient of cBN crystal can be increased linearly by raising the current after the electrochromism occurs, whereas it is irrelevant to the polarization of the incident light. The absorption related to the electrochromism in the cBN single crystal has potential applications in designing and manufacturing electro-optical modulators, optical switches, and other optoelectric devices. 相似文献
3.
The nonlinear photoresponse to a 1.56μm infrared continuous wave laser in semi-insulating (SI) galliu- marsenide (GaAs) is examined. The double-frequency absorption (DFA) is responsible for the nonlinear photoresponse based on the quadratic dependence of the photocurrent separately on the coupled optical power and bias voltage. The electric field-induced DFA remarkably affects the native DFA in SI GaAs. The surface electric field or the surface band-bending of SI GaAs significantly affects the magnitude variation of the Dhotocurrent and dark current 相似文献
4.
Different electro-optic effects, such as Kerr effect, Pockels effect induced by the electric field or strain, and plasma dispersion effect exist in silicon. Experimentally distinguishing these effects is necessary for designing silicon-based electro-optic devices. According to their different polarization dependencies and frequency responses, these effects are measured and distinguished successfully via a transverse electro-optic modulation experiment based on the near-intrinsic silicon sample. The results indicate that Pockels effect induced by the electric field or strain is primary among these effects in the near-intrinsic silicon sample. 相似文献
5.
Diamonds are wide-gap semiconductors possessing excellent physical and chemical properties;thus,they are regarded as very appropriate materials for optoelectronic devices.Based on the Kerr effect,we introduce a simple and feasible method for measuring the third-order nonlinear optical susceptibility of synthetic diamonds.In the experiments,synthetic type I diamond samples and transverse electro-optic modulation systems are utilized.As for the laser with the wavelength of 650 nm,the third-order susceptibility and Kerr coefficient of the diamond samples are obtained at χ(3)1212= 2.17 × 10-23 m2/V2 and S44 = 1.93 × 10-23 m2/V2,respectively. 相似文献
6.
The physical mechanism of two-photon response (TPR) in semi-insulating GaAs is studied. The measured photocurrent generated from the fabricated hemispherical GaAs sample responding to 1.3μm continuous wave laser shows a quadratic dependence on the coupled optical power and no saturation with the bias. The angular dependence of the photocurrent on the azimuth is in agreement with the anisotropy of double-frequency absorption (DFA) in GaAs single crystals. These results demonstrate DFA is the dominant mechanism of TPR in GaAs. 相似文献
7.
8.
The transverse electro-optic(EO)modulation system is built based on cubic boron nitride(cBN)single crystals unintentionally doped and synthesized at a high pressure and high temperature.The photoelectric output of the system includes two parts that can be measured respectively and the value of elements in the linear EO tensor of the cBN crystal can be obtained.This method does not need to measure the absolute light intensity.All of the surfaces of the tiny cBN crystals whose hardness is next to the hardest diamonds are{111}planes.The rectangular parallelepiped cBN samples are obtained by cleaving along{110}planes and subsequently grinding and polishing{112}planes of the tiny octahedral cBN flakes.Three identical non-zero elements of the EO tensor of the cBN crystal are measured via two sample configurations,and the measured results are very close,about 3.68 and 3.95 pm/V,respectively,which are larger than the linear EO coefficients of the general III-V compounds. 相似文献
9.
具有反演对称中心的硅单晶在电场作用下体内的反演对称中心消失,因而理论上应产生偶数阶非线性极化率。从理论上根据矢量与张量的作用,利用(eχf2f)=χ(3).E这一关系和张量变换理论系统地阐述了硅材料在内建电场或外加电场的作用下,具体在方向分别沿[111][、110]和[001]的电场作用下,得到的等效二阶极化率张量(eχf2f)分别与C3v、C2v和C4v点群的二阶极化率张量具有相同的形式,说明在物理性质方面,硅的对称性由Oh群在相应方向电场作用下分别被降低为C3v、C2v和C4v群,因此应该具有相应对称性晶体的二阶非线性光学性质;提出了电场E沿任意方向时硅的等效二阶极化率张量e(χf2f)的计算方法,对研究硅材料和其他具有反演对称中心材料的场致二阶非线性光学性质实验具有指导意义。 相似文献
10.