Polarization beats in a pillar microcavity

The beats of the Stokes luminescence parameters in pillar semiconductor microcavities are theoretically analysed. The beats are originated by a slight in-plane anisotropy of the pillar. The influence of the coherence time of exciton polaritons on the decay rate of polarization oscillations of the emission of light by the cavity is revealed. This link is essential for studies of the dynamic properties of polariton condensates in pillar microcavities.     

垂直腔面发射半导体微腔激光器

评述了垂直腔面发射半导体激光器研究的最新进展,就其结构特点、应变量子阱结构、超晶格镜面和微腔效应作了简要的论述,探讨了进一步降低半导体激光器阈值的途径,介绍了新型的氧化约束型垂直腔面发射半导体激光器,并对微腔激光器中自发辐射增强效应和三维封闭腔的特性给出了描述,同时展望了该器件的应用及发展前景。     

Pump angle and position effects on laser emission from quasicrystal microcavity by nine-beam interference based on holographic polymer-dispersed liquid crystals

We demonstrate pump angle and position effects on lasing from all organic quasicrystal fabricated by nine-beam interference. The output wavelengths of lasing are experimentally investigated with different pump angles. The underlying mechanism is explained by the photonic band edge simulated by finite-difference time-domain method. Additionally, the position effect on lasing is also demonstrated, and the emission characteristics of lasing are studied. The mirrorless laser is featured by low cost, and simple fabrication, which enables quasicrystal based on holographic polymer-dispersed liquid crystal an all organic miniature lasing devices.     

Cavity-Enhanced Third Harmonic Generation

We derive the analytical expression of microcavity-enhanced factor for third harmonic generation in terms of detunings, linewidths, and the Purcell factors of the relevant microcavity modes. It is suitable for microcavities with any dimensions and arbitrary geometric shapes.     

Hybrid excitons in organic–inorganic semiconducting quantum wells in a microcavity

We investigate theoretically the optical properties of composite organic–inorganic semiconductor quantum wells. These properties are dominated by hybrid Frenkel (or charge-transfer) and Wannier–Mott excitonic states. An important effect is the possibility of using the Stark shift to tune the resonance between Frenkel and Wannier–Mott excitons. This fact is very important from a practical point of view because it may be difficult to grow such a structure exactly at resonance. We also discussed the coupling of Frenkel or charge transfer and Wannier–Mott exciton through a microcavity photon. We evaluate the hybrid exciton-polariton Rabi splitting. In the strong coupling regime the Rabi splitting depends essentially on the oscillator strength of the Frenkel or charge-transfer exciton.     

Temperature dependent polariton emission from strongly coupled organic semiconductor microcavities

We investigated the absorption and photoluminescence (PL) of J-aggregates of a cyanine dye both in a thin film format and when used as the active layer in a strongly-coupled microcavity. We show that as temperature is reduced, the absorption linewidth of the J-aggregates narrows and shifts to higher energy. When the J-aggregate is placed in a microcavity we find that the energy of the polariton modes also shifts to higher energies as temperature is reduced. We compare the intensity of PL emission from the upper and lower branches at resonance as a function of temperature, and find that it can be described by an activation energy of 25 meV. PL emission spectra at resonance also suggest that uncoupled excitons inside the microcavity populate the upper polariton branch states.     

Ion bombardment of ordered Zr3Al

The behaviour of the ordered alloy Zr₃Al was investigated by transmission electron microscopy following ion bombardments at temperatures ranging from 30 to 850 K. Utilizing high energy(0.5–2.0 MeV) C⁺, N⁺ and Ar⁺ ion bombardments, observations were made of the irradiation-induced transformation from the ordered → disordered → amorphous states. Information about individual damage cascades was also obtained using both high energy (C⁺. N⁺ and Ar⁺) and low energy (15–120 keV Cu⁺) ion bombardments.     

Optomechanical sensing with on-chip microcavities

The coupling between optical and mechanical degrees of freedom has been of broad interest for a long time. However, it is only until recently, with the rapid development of optical mierocavity research, that we are able to manipulate and utilize this coupling process. When a high Q microeavity couples to a mechanical resonator, they can consolidate into an optomeehanieal system. Benefitting from the unique characteristics offered by optomeehanical coupling, this hybrid system has become a promising platform for ultrasensitive sensors to detect displacement, mass, force and acceleration. In this review, we introduce the basic physical concepts of cavity optomechanies, and describe some of the most typical experimental cavity optomechanical systems for sensing applications. Finally, we discuss the noise arising from various sources and show the potentiality of optomechanical sensing towards quantum-noise-limited detection.     

基于飞秒激光直写的单向单模耦合微腔

对具有高Q值的回音壁模式微腔进行调制来获得单向单模输出,对研究腔光力学和开发高质量的微激光具有重要意义.本文对利用飞秒激光直写加工的耦合回音壁模式微腔的研究进行了简要回顾,具体介绍了微腔结构设计、加工过程、激射和耦合机制研究等.利用飞秒激光直写加工的强大三维图案化能力,灵活地设计实现了具有集成功能的单个微腔和具有不同空间组合位置的多个耦合微腔.基于耦合微腔的微激光具有低阂值,同时显示出良好的单模特性和单向性.结合理论模拟可以证实,微腔与微腔/光栅之间的耦合,一方面支持游标效应和集成滤波两种选模方式,另一方面能够破坏微腔的旋转对称性从而获得单向输出,从而实现了对微腔输出的有效调控.