- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Compensation of Distortions of Polarization Characteristics of Ring Resonators
摘要： The reasons of occurrence of polarization mode distortions and methods of their compensation are investigated. It is demonstrated that sensitivity of lasers with ring resonator to magnetic field may be reduced, if effect of induced polarization anisotropy to be compensated by means of installation of a mirror in resonator in certain position, which complies with the minimum ellipticity angle.
关键词： polarization characteristics of interference mirrors,ring optical resonators,phase anisotropy,information optics
更新于2025-09-23 15:23:52
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Minimally asymmetric state conversion around exceptional singularities in a specialty optical microcavity
摘要： Exploiting scattering matrix (S-matrix) formalism, a unique route for manipulating the exceptional points (EPs) has been reported in a trilayer open optical microcavity with non-uniform real refractive index. The boundaries of the intermediate index layer are appropriately tapered. The cavity is partially pumped by transverse distribution of a balanced gain-loss profile. With strict restriction of balanced gain-loss, controlling infinitesimally small variation of gain-coefficient with simultaneous tapering parameter an EP has been encountered; which is being encircled in cavity parameter space to study dynamics of the coupled states around the EP in the context of robust selective flip-of-state phenomena with lower-asymmetry in state conversion efficiencies. Such a specialty trilayer microcavity with tunable width is reported for the first time; which turns out to be a specific approach to achieve maximum efficiency in conversion with minimum asymmetry. Considering suitable state-of-the-art techniques, this exclusive proposal may open up a fabrication feasible platform for device level implementation of system control exploiting EPs.
关键词： Microcavity devices,Mode-converters,Exceptional points,Avoided resonance crossing,Optical resonators
更新于2025-09-23 15:23:52
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Vapor Sensing with Polymer Coated Straight Optical Fiber Microtapers Based on Index Sensitive Interference Spectroscopy of Surface Stress Birefringence
摘要： Optical micro?ber tapers provide an advantageous platform for sensing in aqueous and gas environments. We study experimentally the photonic transmission in optical ?ber tapers coated with polymethyl methacrylate (PMMA), a polymeric material widely used in optical applications. We demonstrate a durable and simple humidity sensing approach incorporating tapered micro?bers attached to silicon (Si) substrate coated with active polymer layer. A model is described for the load stress effect on the birefringence giving rise to interferences in the transmission spectra, strongly dependent on the coating layer thickness, and disappearing following its slow uniform removal. The sensing approach is based on characterization of the interference patterns observed in the transmission spectra of the taper in the NIR range. The device demonstrated persistent detection capability in humid environment and a linear response followed by saturation to calibration analytes. In each analyte of interest, we de?ne principal components and observe unique calibration plot regimes in the principal component space, demonstrating vapor sensing using polymer coated microtapers.
关键词： microstructured ?bers,optical resonators,optical sensing
更新于2025-09-23 15:21:01
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604-nm high-order vortex beams directly generated from a Pr:YLF laser with a cavity-loss-induced gain switching mechanism
摘要： In this work, we demonstrated, for the ?rst time to the best of our knowledge, high-order vortex beams at 604 nm that were directly emitted from a Pr:YLF crystal laser. By combining a blue-diode-pumped v-type cavity for controllable Gouy phase introduction and o?-axis crystal rotation for high-order HG modes generation, topological charged 604-nm vortex lasers were attained up to the third order. Furthermore, the vortex beams were found to be lasing at 604 nm that was often deemed less prone to lase compared with 607-nm in the same energy manifold. By a detailed spectroscopic study and rate equation analysis, we proposed and con?rmed that the 604-nm transition of Pr:YLF crystal could be favorable in the vortex beam generation by a cavity-loss-induced gain switching process, in which the net gain at 604-nm could surpass that of 607-nm as the cavity loss was amassed beyond a threshold value.
关键词： Interference,Optical pumping,Laser modes,Optical resonators
更新于2025-09-23 15:19:57
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Nonlinear Optics in Microspherical Resonators
摘要： Nonlinear frequency generation requires high intensity density which is usually achieved with pulsed laser sources, anomalous dispersion, high nonlinear coefficients or long interaction lengths. Whispering gallery mode microresonators (WGMRs) are photonic devices that enhance nonlinear interactions and can be exploited for continuous wave (CW) nonlinear frequency conversion, due to their capability of confine light for long time periods in a very small volume, even though in the normal dispersion regime. All signals must be resonant with the cavity. Here, we present a review of nonlinear optical processes in glass microspherical cavities, hollow and solid.
关键词： kerr nonlinearity,optomechanical oscillations,stimulated brillouin scattering,optical resonators,whispering gallery mode
更新于2025-09-23 15:19:57
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[IEEE 2019 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon (EUROSOI-ULIS) - Grenoble, France (2019.4.1-2019.4.3)] 2019 Joint International EUROSOI Workshop and International Conference on Ultimate Integration on Silicon (EUROSOI-ULIS) - InGaN/Si Hetero-Junction Tandem Solar Cell with Self Tunneling Effect: Proposal & Analysis
摘要： We review the physics underlying the process of spontaneous emission, with a special focus on spontaneous emission into a resonator mode. We define the mode volume, verify the fundamental modal dimensions, present the spectral mode profile, the coherence time, the Q-factor, the Fühtbauer–Ladenburg equation, and the Purcell factor, and discuss their influence on different types of lasers. We obtain the relation between peak emission cross section, radiative lifetime, and emission linewidth. By interpreting spontaneous emission as stimulated emission driven by vacuum fluctuations, we derive the spontaneous-emission rate into a resonator mode and establish physical expressions for the fractions of spontaneous emission and total decay from the upper laser level into this mode. Furthermore, we discuss coupling of the atomic system with the coherent field inside a lasing resonator mode, resulting in the formation of a Mollow triplet, and demonstrate that it leads to a reduction of the spontaneous-emission rate into a coherently occupied resonator mode by a factor of 2.
关键词： luminescence,spontaneous emission,optical resonators,laser modes,Lasers
更新于2025-09-23 15:19:57
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - A Novel Low-profile Tightly-coupled Antenna Array
摘要： We review the physics underlying the process of spontaneous emission, with a special focus on spontaneous emission into a resonator mode. We define the mode volume, verify the fundamental modal dimensions, present the spectral mode profile, the coherence time, the Q-factor, the Fühtbauer–Ladenburg equation, and the Purcell factor, and discuss their influence on different types of lasers. We obtain the relation between peak emission cross section, radiative lifetime, and emission linewidth. By interpreting spontaneous emission as stimulated emission driven by vacuum fluctuations, we derive the spontaneous-emission rate into a resonator mode and establish physical expressions for the fractions of spontaneous emission and total decay from the upper laser level into this mode. Furthermore, we discuss coupling of the atomic system with the coherent field inside a lasing resonator mode, resulting in the formation of a Mollow triplet, and demonstrate that it leads to a reduction of the spontaneous-emission rate into a coherently occupied resonator mode by a factor of 2.
关键词： luminescence,spontaneous emission,optical resonators,laser modes,Lasers
更新于2025-09-23 15:19:57
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - LDPC Channel Coding in Ultraviolet Communication System
摘要： We review the physics underlying the process of spontaneous emission, with a special focus on spontaneous emission into a resonator mode. We define the mode volume, verify the fundamental modal dimensions, present the spectral mode profile, the coherence time, the Q-factor, the Fühtbauer–Ladenburg equation, and the Purcell factor, and discuss their influence on different types of lasers. We obtain the relation between peak emission cross section, radiative lifetime, and emission linewidth. By interpreting spontaneous emission as stimulated emission driven by vacuum fluctuations, we derive the spontaneous-emission rate into a resonator mode and establish physical expressions for the fractions of spontaneous emission and total decay from the upper laser level into this mode. Furthermore, we discuss coupling of the atomic system with the coherent field inside a lasing resonator mode, resulting in the formation of a Mollow triplet, and demonstrate that it leads to a reduction of the spontaneous-emission rate into a coherently occupied resonator mode by a factor of 2.
关键词： Lasers,laser modes,optical resonators,spontaneous emission,luminescence
更新于2025-09-19 17:13:59
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Topological Cylindrical Resonators and Optical Fibers
摘要： We propose optical resonators based on the edge modes of a cylindrical multilayer structure with nontrivial topological configuration. We calculate the field confinement and resonator dispersion by a recursive approach able to tackle with arbitrary arrangements of annular concentric layers. We apply the method to a periodical structure with Harper modulation and study the resulting cylindrical edge modes. Conventional circular optical resonators are designed exploiting the effect of total internal reflection or by Bragg structured claddings. The Bragg reflection mechanism allows to decouple the detrimental link between cavity dimensions and cavity losses present if total internal reflection is exploited. Reducing bending losses requires a large core radius, while for achieving a high quality factor small dimensions are needed. We consider photonic topological insulators, sustaining edge states, as a viable alternative for the cladding patterning to achieve optical resonators operating on protected states, immune to disorder and perturbations.
关键词： photonic topological insulators,optical resonators,topological configuration,edge modes,Harper modulation
更新于2025-09-16 10:30:52
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Fast Photon Storage in a Fiber-Based Atom-Cavity System
摘要： Miniaturized ?ber-based optical resonators are emerging as a robust and scalable technology for realizing ?ber-based quantum networks. First demonstrated in [1], these cavities have been integrated with a variety of emitters, e.g. atoms, ions and solid-state systems, to build single-photon quantum interfaces. Our system consists of a single 87Rb atom coupled to a high bandwidth (κ = 2π×40 MHz (cid:2) γ), single-sided ?ber Fabry-Perot cavity (FFPC), Fig. 1(a). The unique system of four in-vacuum lenses, with their focal points coinciding with the ?ber-cavity center, provides the necessary optical access for 3D-cooling and trapping, addressing and high resolution ?uorescence imaging of the atoms, Fig. 1(b). For the D2-transition of 87Rb, the strongly coupled atom-cavity system shows a sixfold Purcell broadening and 90% emission into the cavity mode [2]. Here we present deterministic generation and storage of fast photon pulses. For single-photon generation the atomic state is prepared in F = 1 ground state. A π?polarized classical control laser pulse creates a single photon in the cavity mode with an ef?ciency of ～80%, Fig. 1(c). The pulse shape of the emitted single photon can be tailored by the temporal shape of the control pulse on a time scale lower than the atomic excited state lifetime of ～26 ns, Fig. 1(d). For the storage of fast (short) coherent light pulses, the atomic system is prepared in the |F = 2, m f = ?2(cid:4) state by optical pumping. The temporally shaped input coherent laser pulse at the single-photon level incidents on the cavity mirror while a π?polarized control classical laser pulse with an optimized temporal pro?le, dresses the atom-cavity system such that the storage ef?ciency of the input pulse is maximised. We store photon pulses with a temporal width down to 10 ns with an overall ef?ciency of ～5%.
关键词： 87Rb atom,single-photon quantum interfaces,photon storage,fiber Fabry-Perot cavity,fiber-based optical resonators,quantum networks
更新于2025-09-11 14:15:04