Fiber optical switches

Gonzalez C., Collins S.D., Magnetically actuated fiber-optic switch with micromachined positioning stages, Optics Lett., 1997 22(10) 709-711. 

FI - emission pick-up fiber, PS - fiber optic splitter, F2, F3 - relay fibers, LDD - laser diode driver, LD - laser diode, FOS - fiber optic switch, USB - USB2.0 connector for PC, SI -carousel interface connector. (Reprinted from Dhadwal et al. [2], with permission of Elsevier)... 

The beam travels via fiber to a Matrix Distribution Cabinet (MDC) located near the boiler. A fiber optic switch within this enclosure routes the laser light to the transmitter head on a particular measurement path. The beam transits the measurement location and is focused into a fiber within the receiver head. From here, the beam is routed back by fiber to a fiber optic switch in the MDC and then back to the control rack. 

These include "compact discs" (CD) for read and write devices for computers, and playing music laser printers CVD (compact video discs) for use with TV sets to play movies and the like hand held compact computers fiber-optic switching chambers and medical diagnostic devices. 

NIR radiation can be transmitted down readily available, relatively cheap optical fibers thus allowing spectrometers to be located remotely from the process streams they are monitoring, away from potentially hazardous areas. Optical fibers also provide a convenient means of multiplexing a single spectrometer to several streams, thus reducing the overall cost of the analyses. Optical fibers, optical switching and sample probes have been crucial to the development of NIR spectroscopy for process analytical applications [8, 9]. 

Diffraction gratings that can be switched on and off by an electric field is of interest for applications, including fiber-optic switches and lenses with a dynamically variable focal length (Sutherland et ah, 1994 Zhang and Sponsler, 1992). 

FIGURE 5 Schematic of the first-generation MEMS fiber optic switch made at UCLA. SOURCE UCLA. 

Lee, S. S., E. Motamedi, and M. C. Wu. 1997. Surface-micromachined free-space fiber optic switches with integrated microactuators for optical fiber communication systems. Pp. 85-88 in Proceedings of the 1997 International Conference on Solid-State Sensors and Actuators (Transducers 97), Chicago, 111., June 16-19,1997. New York Institute of Electrical and Electronics Engineers. 

Chips, sensors Fuel cell electrolytes Fuel cell electrodes Information recording Heat exchangers Refractories Pigments, ion lasers Fiber optics Switches Solar cells Displays Catalysts... 

N. A. Riza and S. F. Yuan, Reconfigurable wavelength add-drop filtering based on a Banyan network topology and ferroelectric hquid crystal fiber-optic switches, J. Lightwave Technol. 17, 1575 (1999). 

Switching. Fiber-optical switches are useful in redirecting the optical signal in an optical network. A two-position switch reroutes a signal to one of two output channels. Factors determining the efficiency of a two-position switch are speed, reproducibility, and cross talk. Speeds of a few milliseconds are possible with electromechanical switches. Reproducibility provides the same intensity in the signal every time a switch is made. Cross talk measures how uncoupled one output channel is from the other in a multichannel optical system. 

T. Ebato, T. Kajlwara, and S. Kobayashi, Mechanical fiber optic switching using PVDF bimorph, Eleetronks Lett. I6 SX (1980). 

In photodetectors (qv) for photocouplers, optical switches, fiber optics, communication, and imaging, the materials used are InGaAs, InGaAsP, and... 

The advanced control room uses fiber optics, microprocessors, and digital monitoring and control. This includes self-testing, automatic calibration, user interactive from panels, full multiplex, standardization of the man-machine interface, common circuit cards, and wide-range flux monitors to eliminate range switching on startup. 

The speed of information transfer can be increased by switching from twisted pair cables to coaxial or fiber optics, however, these types of cables add to the installation costs. In the future, communications between sensors and multiplex boxes and the rest of the system may use a combination of technologies including traditional means such as twisted wire and coaxial and non-traditional methods such as infrared or radio wave. 

Both PDA and CCD fiber-optic spectrophotometers may be combined with a fiber switch or multiplexer to access multiple probes or cells in a sequential fashion. Multiplexers are available to select from among 2, 6, 9, or even more fibers/probes. 

This is a development of the above where a fiber-optic linked hqnid sample transmission cell is integrated with the sample fast loop cabinet (Figures 5.24 and 5.25). There can be multiple sample streams, take-offs and fast loops, each with its own separate fiber-optic transmission cell. The analyzer can either be local with short fiber-optic runs to the sampling cabinet(s), or remote, where a safe area location for the analyzer module may be feasible, but at the cost of longer, potentially less stable fiber-optic runs. This system avoids physical stream switching. 

The fabrication process of vanadium oxide (VO2) has also been studied using RBS/C. Since optieal and electrical properties of VO2 are dramatically changed at 68°C due to phase transition, VO2 is regarded as one of the candidates for thermally activated electronic or optical switching devices for optieal fibers or sensors. To obtain the desired properties, the development of the fabrication process for very thin films, without crystalline defects on various substrates, is required. Single-crystalline VO2 thin films on (0001) plane of a sapphire substrate have been synthesized by a laser ablation method. The quality of VO2 was examined by X-ray diffraction and RBS/C method. The eleetrieal resistanee and the optical transmittance of the VO2 film were measured under inereasing and deereasing temperatures. At a temperature of 68 °C, an abrupt transition of resistanee from metal to... 

Nonexpendable light sources, such as a Q-switched pulsed laser can be protected. from destructive forces encountered in the photography of explosive material by piping the light through fiber optics, to the experimental zone. Occasionally lens systems are used to relay the light from mirrors located near a protective barrier shielding the laser (Ref 16)... 

Experimental work and theoretical investigation show an important role of spatial chaos in optical fibers, directional couplers, and generally in all-optical switching devices [96/97]. 

Resins are used in electromc/electncal applications (connectors, circuit boards that are vapor and wave solderable, microwave transparent radomes, integrated circuit chip carriers, miniature switches, explosion proof enclosures, lamp reflectors, and high-precision fiber optic components). Polyetherimide is used for medical components (hat require all forms of sterilization. Other uses are found in the transportation field, dual-ovenable cookware, as well as bearings, fasteners, and advanced composites. 

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