半导体集成光子学的研究与进展

<正> 固体光子学的提出是建立在把光子技术与电子技术相类比的基础上的。在传统的电子学中,电子只是作为一种荷电粒子的信息载体出现,对其所传输的信息的表征,往往只由电子运动速度的矢量所体现,因而它对信息的传输与处理的速度不能不受到回路分布参数的限制(一般为10 ~9s)。光子的运动不会受到回路分布延迟的影响,因而利用光子作为信息的载体可大大提高信息系统的传输与处理速度。再则,由于光的传输又呈现波的属性,作为信息载体。

征稿启事

《Semiconductor Photonics and Technology（半导体光子学与技术）》是由工业和信息化部主管，中国电子科技集团公司第四十四研究所主办的英文期刊（季刊，国内外公开发行）。

Information for Authors

＂Semiconductor Photonics and Technology＂ is an academic journal sponsored by Chongqing Optoelectronies Research Institute, published quarterly and distributed home and abroad. It has been indexed in CA, AJI CJFD, and several other organizations. The primary purpose is to report current important developments, academic reviews and applications in photonics and optoelectronics, emphaszing on devices, materials, systems,technics, etc.

Information for Authors

＂Semiconductor Photonics and Technology＂ is an academic journal sponsored by Chongqing Optoelectronics Research Institute, published quarterly and distributed home and abroad. It has been indexed in CA, AJ; CJFD,and several other organizations. The primary purpose is to report current important developments, academic reviews and applications in photonies and optoelectronies, emphaszing on devices, materials, systems , technics, etc.

Vibration Spectra of Quasi-confined Optical Phonon Modes in an Asymmetric Wurtzite AlxGa1-xN/GaN/AlyGa1-yN Quantum Well

Based on the dielectric continuum model and Loudon＇s uniaxial crystal model, the properties of the quasi. confined （QC） optical phonon dispersions and the electron-QC phonons coupling functions in an asymmetric wurtzite quantum well （QW） are deduced via the method of electrostatic .potential expanding. The present theoretical scheme can naturally reduce to the results in symmetric wurtzite QW once a set of symmetric structural parameters are chosen. Numerical calculations on an asymmetric AlN/GaN/AIo,15 Gao.85N Wurtzite Q W are performed. A detailed comparison with the symmetric wurtzite QW was also performed. The results show that the structural asymmetry of wurtzite QW changes greatly the dispersion frequencies and the electrostatic potential distributions of the QC optical phonon modes.

Fabrication and characterization of 1 550 nm polarization-insensitive semiconductor optical amplifiers

A 1 550 nm polarization-insensitive semiconductor optical amplifier (SOA) was fabricated with InGaAs tensile-strained bulk active region.Beam propagation method and planar wave expansion method are used to calculate the mode field profile and the mode reflectivity.For the SOA with a buried waveguide deviated 7° from the normal direction of cleaved mirrors,the thickness tolerance of the mirror is 3% for keeping the reflectivity of TE mode and TM mode less than 10 -4 simultaneously.For a SOA with a cavity length of 800 μm,the polarization sensitivity of amplified spontaneous emission spectra is less than 0.5 dB at an injection current of 250 mA,the corresponding fiber-to-fiber gain is 11.9 dB at 1 550 nm with a 3 dB bandwidth of 63 nm ,and the saturation output power is 5.6 dBm .The noise figure shows 8.8 and 7.8 dB at 1 550 and 1 570 nm,respectively.For a packaged SOA with a cavity length of 1 000 μm,the fiber-to-fiber gain is 15 dB at an injection current of 190 mA.

Vibration Spectrums of Polar Interface Optical Phonons in GaAs／AlAs Cylindrical Quantum Dots

The dispersions of the top interface optical phonons and the side interface optical phonons in cylindrical quantum dots are solved by using the dielectric continuum model. Our calculation mainly focuses on the frequency dependence of the IO phonon modes on the wave-vector and quantum number in the cylindrical quantum dot system.Results reveal that the frequency of top interface optical phonon sensitively depends on the discrete wave-vector in z direction and the azimuthal quantum number, while that of the side interface optical phonon mode depends on the radial and azimuthal quantum numbers. These features are obviously different from those in quantum well, quantum well wire,and spherical quantum dot systems. The limited frequencies of interface optical modes for the large wave-vector or quantum number approach two certain constant values, and the math and physical reasons for this feature have been explained reasonably.

Electronic structure and optical property of boron doped semiconducting graphene nanoribbons

We present a system study on the electronic structure and optical property of boron doped semiconducting graphene nanoribbons using the density functional theory. Energy band structure, density of states, deformation density, Mulliken popular and optical spectra are considered to show the special electronic structure of boron doped semiconducting graphene nanoribbons. The C-B bond form is discussed in detail. From our analysis it is concluded that the Fermi energy of boron doped semiconducting graphene nanoribbons gets lower than that of intrinsic semiconducting graphene nanoribbons. Our results also show that the boron doped semiconducting graphene nanoribbons behave as p-type semiconducting and that the absorption coefficient of boron doped armchair graphene nanoribbons is generally enhanced between 2.0 eV and 3.3 eV. Therefore, our results have a great significance in developing nano-material for fabricating the nano-photovoltaic devices.

Ⅲ-Ⅴ semiconductor nanocrystal formation in silicon nanowires via liquid-phase epitaxy

Direct integration of high-mobility III-V compound semiconductors with existing Si-based complementary metal-oxide-semiconductor （CMOS） processing platforms presents the main challenge to increasing the CMOS performance and the scaling trend. Silicon hetero-nanowires with integrated III-V segments are one of the most promising candidates for advanced nano-optoelectronics, as first demonstrated using molecular beam epitaxy techniques. Here we demonstrate a novel route for InAs/Si hybrid nanowire fabrication via millisecond range liquid-phase epitaxy regrowth using sequential ion beam implantation and flash-lamp annealing. We show that such highly mismatched systems can be monolithically integrated within a single nanowire. Optical and microstructural investigations confirm the high quality hetero-nanowire fabrication coupled with the formation of atomically sharp interfaces between Si and InAs segments. Such hybrid systems open new routes for future high-speed and multifunctional nanoelectronic devices on a single chip.

High Efficiency Four-Wave Mixing with Relaxation Coupling of Longitude-Optical Phonons in Semiconductor Quantum Wells

The time-dependent analysis of four-wave mixing(FWM) has been performed in four-level double semiconductor quantum wells(SQWs) considering the cross-coupling of the longitude-optical phonons(LOP) relaxation. It is shown that both the amplitude and the conversion efficiency of the FWM field enhance greatly with the increasing strength of cross-coupling of LOP relaxation. Interestingly, a double peak value of the conversion efficiency is obtained under a relatively weak single-photon detuning considering the LOP coupling. When the detuning becomes stronger,the double peaks turn into one peak appearing at the line respect to the about equality two control fields. The results can be interpreted by the effect of electromagnetically induced transparency and the indirect transition. Such controlled high efficiency FWM based on the cross-coupling LOP may have potential applications in quantum control and communications.

Ultra-Low Threshold Optical Bistability and Multi-Stability in Dielecrtric Slab Doped with Semiconductor Quantum Well

A scheme for switching of the optical bistability(OB) and multi-stability(OM) in a dielectric slab doped with a three-level ladder-configuration n-doped semiconductor quantum well is simulated. It is shown that the bistable behavior of the system in dielectric slab can be controlled via amplitude or relative phase of applied fields. This optical system may provide some new possibilities for test the switching process.