Performance Of Optical Switch Research Articles

ẢNH HƯỞNG CỦA ĐỘ KẾT HỢP ĐƯỢC TẠO BỞI PHÁT XẠ TỰ PHÁT VÀ BƠM KHÔNG KẾT HỢP LÊN CHUYỂN MẠCH TOÀN QUANG TRONG MÔI TRƯỜNG NGUYÊN TỬ BA MỨC BẬC THANG KHI CÓ MẶT CỦA PHA TƯƠNG ĐỐI

This paper investigates the impact of spontaneously generated coherence (SGC) and relative phase on the propagation of a probe laser pulse in the presence of an incoherent pump field. It was discovered that when the control laser field is turned on, the medium forms an electromagnetically induced transparency (EIT) effect. Hence, the propagation of the probe laser pulse has a like-soliton form/shape. On the contrary, the probe laser field is rapidly attenuated when the control laser field is turned off. This feature allows the creation of a mechanism to turn “off” and “on” the probe laser field through “turning off” and “on” the control laser field, i.e., an all-optical switching mechanism based on EIT. Besides intensity and frequency, the laser field is also characterized by polarization and phase. The EIT has the nature of quantum interference, so it is very sensitive to changes in polarization, especially in the presence of relative phase between laser fields. Therefore, they also significantly affect pulse propagation and optical switching performance. The research results could be helpful for experimental observations or applications in photonic devices such as logic gates, quantum optical information processors, and quantum computers.

Electromagnetically induced transparency via localized surface plasmon mode-assisted hybrid cavity QED

In recent years, most studies have focused on the perfect absorption and high-efficiency quantum memory of the one-sided system, ignoring the characteristics of its optical switching contrast. Thus, the performance of all-optical switching and optical transistors is limited. Herein, we propose a localized surface plasmon (LSP) mode-assisted cavity QED system which consists of a Λ-shaped three-level quantum emitter (QE), a metal nanoparticle and a one-sided optical cavity with a fully reflected mirror. In this system, the QE coherently couples to the cavity and LSP mode respectively, which is manipulated by the control field. As a result, considerably high and stable switch contrast of 90% can be achievable due to the strong confined field of the LSP mode and perfect absorption of the optical medium. In addition, we obtain a power dependent effect between the control field and the transmitted frequency as a result of the converted dark state. We employ the Heisenberg–Langevin equation and numerical master equation formalisms to explain high switching, controllable output light and the dark state. Our system introduces an effective method to improve the performance of optical switches based on the one-sided system in quantum information storage and quantum communication.

Ultra-High Quality Factor Resonances in a Pinwheel-Shaped All-Dielectric Metasurface Based on Bound States in the Continuum

Combining with the bound states in the continuum (BICs) theory in all-dielectric metasurfaces has become an extensively used method to excite multiple high quality(Q) factor Fano resonances, which remarkably enhance the performance of structures to be applied to refractive index sensors. In this article, a novel silicon pinwheel-shaped all-dielectric metasurface in the near-infrared region is designed and numerically investigated. Two Fano resonances are excited in the original structures. After breaking the symmetry of the original structures in combination with the BIC theory, four sharp Fano resonances are excited and the maximum Q-factor exceeds 3.9 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> when <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">δ</i> = 10 nm. With the asymmetric parameter <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">δ</i> = 80 nm, multiple Fano resonances could be turned on and off by turning the polarization of the incident light, which performs excellent characteristics in optical switches. Both in the original structures and in the asymmetric state it offers outstanding sensing characteristics. Furthermore, with <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">δ</i> = 80 nm and the polarization angle 90 degrees, the sensitivity and the figure of merit (FOM) could respectively reach up to 355 nm/RIU and 1375.97 RIU <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> . The designed structures may provide a way to enhance the performance of bio-chemical sensors, optical switches, and nonlinear optics.

Operating performance of silicon photonic optical switches integrated with WDM filters for low-latency edge-computing platforms

We investigated the performance of a silicon photonic device integrating pn-junction-type Mach-Zehnder interferometer optical switches with wavelength-division-demultiplexing and multiplexing (WDM-DEMUX and MUX) filters that perform switching operations to transmit packet data between edge computing. After separating the 1535 and 1565 nm signals with the Mach-Zehnder delay interferometer-type WDM-DEMUX/MUX filters, cascaded dynamic switching operation with a few nanoseconds turn-on/off for On-Off keying (OOK) signals at 10 Gbps were achieved. The power penalty difference between the input and output was within 0.5 dB for 1565-nm signals. We also verified the switching operation at a bit rate of 25 Gbps and observed clear eye openings.

First-principle study on the conductance performance of Salicylidene Ethylamine molecular optical switch and its alkyl halide derivatives

First-principle study on the conductance performance of Salicylidene Ethylamine molecular optical switch and its alkyl halide derivatives

Design of a temperature-control optical switch based on conjoined-tubular anti-resonance fiber with toluene core

In this paper, a temperature-control optical switch is designed based on a conjoined-tubular anti-resonance optical fiber (CTF). The CTF adopts eight pairs of conjoined tubes and four vertical-layout holes were coated with Au to increase the fiber confinement loss (Loss). Toluene was used as transmission medium to injected into the CTF core. The proposed switch produces a Loss difference over 100 dB and ER more than 30 dB. Influence of switch material refractive index and structural parameters on optical switch performance was further discussed. The proposed optical fiber switch has the features of simple structure, small size, broad working wavebands and adjustable operation temperature, which promises broad application prospects in industry, chemistry, biology and other fields.

Preparation of concentration dependent nitrogen sulfur Co-doped graphene quantum dots by UV irradiation and reversible optical switch of hydroxypropyl methyl cellulose

Nitrogen and sulfur co-doped graphene quantum dots (N, S-GQDs) are prepared by using o-phenylendiamine and catechol as raw materials under UV irradiation in dimethyl sulfoxide (DMSO) solution for 2 h. The resultant N, S-GQDs show uniform size, good crystallinity and fluorescence stability. The tunable polychromatic luminescence is obtained by adjusting the concentration of N, S-GQDs. Then, N, S-GQDs/HPMC composite material is designed and synthesized, which exhibits light responsive optical switching performance owing to micro-aggregation efficacy of N, S-GQDs to transform light into heat and drive the phase transition of hydroxypropyl methyl cellulose (HPMC). Therefore, the prepared N, S-GQDs/HPMC with excellent solar modulation ability can easily switch between opaque and transparent states depending on weather condition. In the end, the thermoresponsive property of N, S-GQDs/HPMC endows it with good performance as functional materials matrix.

Low-field onset of Wannier-Stark localization in a polycrystalline hybrid organic inorganic perovskite

Methylammonium lead iodide perovskite (MAPbI3) is renowned for an impressive power conversion efficiency rise and cost-effective fabrication for photovoltaics. In this work, we demonstrate that polycrystalline MAPbI3s undergo drastic changes in optical properties at moderate field strengths with an ultrafast response time, via transient Wannier Stark localization. The distinct band structure of this material - the large lattice periodicity, the narrow electronic energy bandwidths, and the coincidence of these two along the same high-symmetry direction – enables relatively weak fields to bring this material into the Wannier Stark regime. Its polycrystalline nature is not detrimental to the optical switching performance of the material, since the least dispersive direction of the band structure dominates the contribution to the optical response, which favors low-cost fabrication. Together with the outstanding photophysical properties of MAPbI3, this finding highlights the great potential of this material in ultrafast light modulation and novel photonic applications.

Optical Isomerization and Photo-Patternable Properties of GeO2/Ormosils Organic-Inorganic Composite Films Doped with Azobenzene

GeO2/organically modified silane (ormosils) organic-inorganic composite films containing azobenzene were prepared by combining sol-gel technology and spin coating method. Optical waveguide properties including the refractive index and thickness of the composite films were characterized by using a prism coupling instrument. Surface morphology and photochemical properties of the composite films were investigated by atomic force microscope and Fourier transform infrared spectrometer. Results indicate that the composite films have smooth and neat surface, and excellent optical waveguide performance. Photo-isomerization properties of the composite films were studied by using a UV–Vis spectrophotometer. Optical switching performance of the composite films was also studied under the alternating exposure of 365 nm ultraviolet light and 410 nm visible light. Finally, strip waveguides and microlens arrays were built in the composite films through a UV soft imprint technique. Based on the above results, we believe that the prepared composite films are promising candidates for micro-nano optics and photonic applications, which would allow directly integrating the optical data storage and optical switching devices onto a single chip.

Optical switching performance of thermally oxidized vanadium dioxide with an integrated thin film heater

Optical switching performance of vanadium dioxide produced by thermal oxidation of vanadium is presented in this paper. A 100nm thick vanadium was oxidized under controlled conditions in a quartz tube furnace to produce approximately 200nm thick VO2. The substrate was appropriately coated on the front and back side to reduce reflection in the cold state, and an integrated thin film heater was fabricated to allow in-situ thermal cycling. Electrical measurements show a greater than three orders of magnitude change in resistivity during the phase transition. Optical measurements exhibit 70% transparency at 1500nm and about 15dB extinction across a wide spectral band between 1000nm and 3000nm. These results are used to show a huge optical bistability effect in VO2-based devices.

Approaching ultrathin VO2 films on sapphire (001) substrates by biased reactive sputtering: Characteristic morphology and its effect on the infrared-light switching

Ultrathin VO2 films with insulator-metal transition (IMT) were successfully fabricated on sapphire (001) substrates by utilizing radio frequency-biased reactive sputtering. We realized a 6 nm-thick VO2 film that shows resistance change over 2 orders of magnitude. Microscopic observations combined with energy dispersive x-ray analyses revealed characteristic networking morphology in VO2 films with thickness up to around 10 nm. It was found through micro-Raman analyses that a 30 nm-thick film possessed flat surface and ordered lattice with strong in-plane tensile stress. We evaluated the thickness dependence of optical switching performance for infrared-light. The results suggest that the thickness of the VO2 films should be carefully selected for realizing required performances of optical switching, which depends on not only IMT but also characteristic morphological aspects.

Effect of ultraviolet radiation exposure on optical nonlinearity and switching traits of SnO2 thin films deposited by thermal evaporation

Highly transparent amorphous SnO2 thin films were deposited using the thermal evaporation method and characterized. The influence of the UV radiation exposure (for approximately 2 h) on the morphology, linear and nonlinear optical properties of the films was evaluated for the first time. The optical switching performance of the as-deposited thin films was examined using the pump–probe technique. A continuous wave (CW) diode-pumped solid-state laser (532 nm with maximum power of 100 mW) and He-Ne laser (633 nm with maximum power of 35 mW) was used for the pump and probe beam, respectively. The band gap energies of the films were calculated using the Mott and Davis model fitting procedure. The films transmittance was increased and band gap was decreased upon the UV exposure. The signal modulations in the films were observed with the increase in the pump power. The signal intensities of both as-deposited and UV radiation exposed films were correspondingly dropped from 7.58 to 7.47 mW and from 8.16 to 8.05 mW, when the pump power was raised beyond 20 mW. The achieved SnO2 films displayed unaltered dynamic range under the UV radiation exposure. In addition, the nonlinear absorption coefficients of the UV radiation exposed films were increased from 0.10139 to 0.36435 cm W−1. This indicated the stabilization of the films upon the UV exposure and subsequent removal of the excess oxygen. The higher value of the nonlinear absorption by the films satisfied their figure of merit. The proposed SnO2 thin films may be effective for the development of the nonlinear optical devices working in the UV region.

A simulation based performance evaluation of optical ethernet switch

&lt;p class="FigureCaption"&gt;&lt;span&gt;With the advent of several new cloud radio access network (C-RAN) technologies, today’s networking environment is dramatically altered and is experiencing a rapid transformation. One of the most important is ethernet based C-RAN, in support of which many products such as optical Ethernet switches have recently appeared on the market. This paper presents the performance analysis of such switches with respect to packet loss ratio (PLR), latency and packet delay variation (PDV). We employed the Simula based on discrete event modelling on Simula (DEMOS), a context class for discrete event simulation to simulate a cut-through optical ethernet switch under two types of traffics: high priority (HP) traffic and low priority (LP) traffic. In this way, the paper evaluates the optical Ethernet switch performance quantitatively. The results obtained from the simulator showed that the high quality of service was reflected on HP traffic and the low quality of service in LP traffic. Hence, HP traffic can be used for transporting radio over ethernet (RoE) traffic while LP traffic can used for transporting time insensitive application. It is also found that HP traffic experiences a PDV equals to the duration of maximum sized LP traffic in Optical Ethernet switch.&lt;/span&gt;&lt;/p&gt;

Adjusting the Third-Order Nonlinear Optical Switch Performance Based on Azobenzene Derivatives

Adjusting the Third-Order Nonlinear Optical Switch Performance Based on Azobenzene Derivatives

Optical switching and nanothermochromic studies of VO2(M) nanoparticles prepared by mild thermolysis method

Vanadium dioxide (VO2) has been widely studied due to its promising thermochromic property. VO2 nanoparticles film exhibits a unique nanothermochromic advantage with higher light transmittance (Tlum) and larger solar light transmittance modulation (∆Tsol) than continuous film. In this paper, a mild thermolysis method was developed to prepare VO2 nanoparticles with controlled size and morphology, which was then used to build the nanothermochromic films. By using vanadyl ethylene glycol (VEG) nanorods as a precursor, VO2 nanoparticles can be obtained at a thermolysis temperature as low as 250 °C within 5 min under static argon atmosphere. The VEG nanorods with uniform size and excellent dispersity were prepared from amorphous vanadium oxide nanopowders synthesized by electrochemical anodic-oxidation of vanadium target. The influence of the thermolysis conditions on the microstructure, phase transition and thermochromic properties of VO2 nanoparticles were investigated and discussed. By combining with transparent conductive substrate ITO, the VO2 nanoparticles films demonstrate an active optical switching performance, and the optimal thermochromic properties with Tlum of 48% and ∆Tsol of 11% can be achieved.

Ultrafast plasmon polaritons doubly resonant on a single silver nanoshell.

Ultrafast surface plasmon polaritons (SPPs) were observed in a silver nanoshell grating, which was produced by depositing a roughly sinusoidal dielectric grating with a continuous layer of silver. Two SPP modes were observed to propagate along the top and bottom surfaces of the silver nanoshell, modulating the reflection spectra in the space above and below the silver nanoshell, respectively. These two SPP modes are located independently at a shorter and a longer wavelength, exciting the asymmetric and symmetric oscillation of the plasmonic electrons, respectively. The asymmetric mode was excited by the diffraction anomaly along the silver/air interface, whereas, the symmetric by the waveguide mode within the ITO grating layer, which was defined by the high reflection at the ITO/silver interface and the total reflection at the ITO/substrate interface. Different optical switching performance with different lifetimes was measured for the two resonance modes.

Concentration modulated photoluminescence and optical switching performance of graphene-oxide quantum dots

Graphene oxide quantum dots (GOQDs) have drawn much attention for their modulated bandgap rendering their application in optoelectronic devices. In this study, we present comprehensive photoluminescence properties of GOQDs and its related optical transitions, which agree with recent theoretical predications. In particular, ormosil gel glasses doped GOQDs was synthesized to achieve tunable photoluminescence. We also report the third-order nonlinear optical properties of the quantum dots, which were studied by using Z-scan technique. The evaluated one-photon and two-photon figures of merit demonstrate that GOQDs could be a promising candidate for the optical switching applications in a broad wavelength region.

FDTS as Dewetting Coating for an Electrowetting Controlled Silicon Photonic Switch

The self-assembled monolayer FDTS (1H,1H,2H, 2H-Perfluorodecyltrichlorosilane) is presented as suitable dewetting coating material for an electrowetting on dielectrics (EWOD) controlled silicon photonics switch deployed in fiber optic telecommunication systems. The anti-sticking characteristics of Perfluorodecyltrichlorosilane (FDTS) are compared to those of polytetrafluoroethylene (PTFE) as most common dewetting coating for EWOD devices. It is shown that FDTS could outperform other materials such as PTFE when an extremely thin, long-term stable, and uniform layer is required. In the specific case, FDTS is applied in vapor phase as anti-sticking coating to the active optical surface of the integrated silicon photonics switch thus enabling the EWOD driven liquid motion. The suitability of the coating is presented by contact angle measurements and durability tests carried out with the switching liquids. Finally, it is demonstrated by optical measurements that the FDTS coating has a neglectable influence on the optical switching performance.

Transparent AlON ceramic combined with VO2 thin film for infrared and terahertz smart window

Transparent AlON ceramics are intriguing window materials with excellent mechanical strength and superb optical transparency from the near ultraviolet to the mid-infrared range. However, previous studies focused their investigations in the visible range; therefore, the application of transparent AlON ceramics to tunable windows has yet to be reported. In this work, a VO2 thin film with a characteristic semiconductor-metal phase transition (SMT) was fabricated on a transparent AlON ceramic, which exhibited remarkable tunable switching properties in the infrared and terahertz ranges. The transparent AlON ceramic was prepared by a two-step method, which included carbothermal reduction and pressureless sintering. The resulting ceramic exhibited high transparency of over 70% in the visible-infrared range and a notable THz transmission of 64.5–73.9% at 0.1–1.5 THz. The VO2 thin film was prepared on a transparent AlON ceramic using the sol-gel method and showed excellent optical and electric switching performance. The square resistance variance was close to four orders of magnitude, and an infrared switching ratio of over 40% was obtained. Furthermore, the combined structure showed an efficient THz switching ratio of approximately 70.9%. This study proposes a composite material combined with a transparent ceramic and a phase transition oxide and provides great insights into their application in infrared and terahertz smart windows as well as in switching devices.

A Scalable, Partially Configurable Optical Switch for Data Center Networks

Optical circuit switching may be instrumental in meeting the cost, energy, and aggregate bandwidth requirements of future data center networks. However, conventional MEMS beam-steering cross-connects cannot provide submillisecond switching with the port count necessary for data centers. Here, we investigate a novel noncrossbar selector switch architecture and pupil-division switching layout to improve optical switching performance by relaxing the requirement of arbitrary switch configurability. This architecture and switch design enable MEMS beam-steering micromirrors to scale to microsecond response speeds while supporting high port count and low loss switching, and can realize a number of useful interconnection topologies. We present the design, fabrication, and experimental characterization of a proof-of-principle prototype using a single comb-driven MEMS mirror to achieve 150 μs switching of 61 ports between four preprogrammed interconnection mappings. We demonstrate the scalability of this switch architecture with a detailed optical design of a 2048-port selector switch with 20 μs switching time.