Kind Of Optical Switching Research Articles

Two multifunctional Eu-MOFs with dual photochromic and luminous centers for multiple optical switches and anti-counterfeiting properties

In this work, two multifunctional Eu-MOFs with dual photochromic and luminous centers, formulated as Eu3[(ipbp)4·6H2O]·3H2O (1) and Eu[(ipbp)·(p-BDC)·H2O] (2) (ipbp = 1-(3,5-isophthalic acid)-4,4′-bipyridine chloride, p-BDC = terephthalate), were successfully constructed by solvothermal reactions. The carboxylate pyridine ligand gives the two frameworks excellent photochromic properties, while the metal europium endows the two compounds splendid luminous properties. In addition, the application of the two compounds in three kinds of optical switches is further demonstrated. Finally, the two compounds with dynamic multicolor anti-counterfeiting properties were also explored. This work not only proposed bicentric light-emitting and color-changing materials, but also provided a new strategy for studying multiple optical switches and dynamic anti-counterfeiting.

A Research on Key Technologies in All-Optical Label Switching Networks

With the rapid development of Internet technology, the capacity of communication system is increasing rapidly and traditional switching technology based on optical-electrical-optical (O/E/O) conversion cannot satisfy requirements for information exchange. Construction of a high-speed, large-capacity, high-bandwidth all-optical switching network will be the future direction of communication systems. In this paper, the key technologies in all-optical label switching networks are investigated. First, five kinds of optical label technologies are studied. The principles and implementation methods of them are analyzed and compared. Then, optical switching fabrics based on different kinds of optical switches are discussed. Next, a 160Gb/s Optical Time Division Multiplexing (OTDM) signal 1 × 8 packet switching experiment is introduced. Finally, the research work is summarized, and the design of core nodes in optical packet switching network is prospected.

Electric-field-controlled optical switch using Kerr effect and gradient of the composition ratio Nb/(Ta + Nb)

By exploiting the Kerr effect and the gradient of the composition ratio m, Nb/(Ta+Nb) in mol%, in KTa1−xNbxO3 (KTN) crystals, we have designed an electric-field-controlled optical switch. The operating principle of the switch is described. During the switching process, the incident linearly polarized beam is orthogonally deflected as it propagates through the crystals. The g11/g12 ratio (>10), wavelength range (491–1064nm), I–V characteristics (0–800V), extinction ratio (0–1), gradient of Curie temperature (21–22.9°C), response time that may be in ns order, and influence of the photorefractive effect were studied. The results show that our design provides a new kind of optical switch with macro scale (mm order), adjustable extinction ratio (0–1), wide wavelength range (491–1064nm).

The Study of a Novel Optical Communication Device

A novel optical communication device is investigated in this paper. The device is a kind of optical switch. The intensity of emergent light is tunable continuously by introducing liquid crystal technique. Holographic technique is used to fabricate this optical device. According to optical theories and through many experiments, the ideal optical switching device can be obtained when the photosensitive monomers are mixed together with liquid crystal with certain weight ratio. The emergent light intensity of liquid crystal grating can be modulated by electric field because of the electric control characteristics of liquid crystal. The output light is only 5% of the incident light when the electric field is more than 15V. Besides, the liquid crystal also has the advantages of large electro-optic coefficient, fast response speed and so on. Consequently, the liquid crystal grating has immense potential productivity in passive optical communication device such as optical switching and variable optical attenuator.

Modular Optoelectronic Microfluidic Backplane for Fluid Analysis Systems

We report on the development of backplane modules with integrated microvalves and optical switches enabling custom-made system design of analysis systems. The backplane modules are reversibly interconnected by magnetostatic connectors and provide optical and fluidic coupling to four neighboring backplane modules and one optical sensor module, which is mounted on top. This concept allows for selectively guiding fluids and light to the sensor modules to be operated. We integrated shape memory alloy (SMA) microvalves in different designs and two kinds of optical switches, i.e., one linearly actuated assembly of optical elements and one based on an electrostatically deflectable mirror. We manufactured the modules in polymers and carried out optical and fluidic characterization. The functionality of the backplane is demonstrated by interconnecting two optical sensor modules with integrated spectrometer and photodiode color sensor, respectively. Herewith, we carried out fluorescence transmission experiments.

Optical switch with low-phase transition temperature based on thin nanocrystalline VO x film

An optical switch is fabricated by using micromachining technology, which is based on thin nanocrystalline vanadium oxide (VO x ) film, and it consists of four layers: a silicon (Si) substrate layer, a VO x layer, a Si 3N 4 buffer layer, and an aurum (Au) electrode layer. By applying a switching power supply to a pair of the Au electrodes, the optical switch is controlled to exhibit from an “on” state with semi-conducting phase to an “off” state with metallic phase. The optical switch performance is investigated, and testing results show that its extinction ratio is about 14 dB, its switching response time can achieve about 1.5 ms, and the power dissipation required for stimulating switching to work can be below about 15 mW at least, which is lower than the power dissipation of conventional optical switches based on microstructure thin vanadium dioxide (VO 2) films. This kind of optical switch is potential to be applied as optical switch for optical communication.

Microwave-Controlled Light-Pulse Propagation in a Driven A-Type Atomic System with Two-Folded Levels

The temporal and spatial dynamics of one weak probe laser pulse, propagating through a A-type atomic medium with two-folded levels under the resonant excitation of one microwave driving field and one strong control field, is investigated in this paper. By numerically solving coupled Bloch-Maxwell equations, it is found that, in the absence of the microwave driving field, the atomic medium is transparent to the probe pulse at line center, which propagates over sufficiently long distances. By contrast, when the microwave driving field is applied, the probe pulse at line center can be rapidly absorbed on propagation. This substantial reduction of probe transmittance caused by the microwave driving field may lead to potential applications in designing a new kind of optical switching.

Double‐Inverse‐Opal Photonic Crystals: The Route to Photonic Bandgap Switching

AbstractPhotonic crystals with a complete bandgap can stop the propagation of light of a certain frequency in all directions. We introduce double‐inverse‐opal photonic crystals (DIOPCs) as a new kind of optical switch. In the DIOPC, a movable, weakly scattering sphere is embedded within each pore of the inverse‐opal photonic crystal lattice. Switching between a diffusive reflector and a photonic crystal environment is experimentally demonstrated. Theory shows that a complete bandgap can be realized that can be opened or closed by moving the spheres. This functionality opens up new possibilities for the control of light emission and propagation. The close link and interaction between the chemical synthesis and the computational design and analysis underlines the interdisciplinary focus of this report.

Fast optical switching via stimulated Raman adiabatic passage.

We demonstrate a new approach to fast optical switching with a technique based on stimulated Raman adiabatic passage in which a laser pulse switches the probe field on and off via another coupling pulse. This new kind of optical switching is not limited by the decay rate of an excited state and can operate in the subnanosecond time domain. The experimental observation in Rb atomic vapor is in good agreement with numerical simulations.