Optical fibers devices

Acharya BR, Rmpenkin T, Ramachandran S, Wang Z, Huang CC, Rogers JA (2003) Tunable optical fiber devices based on broadband long-period gratings and pumped microfluidics. Appl Phys Lett 83 4912-4914... 

Fig. 3 Wetted optical fiber device with the end of a fiber inserted directly into the analyte flow stream...

A sample compartment, where the sample cell is positioned for measurements (alternatively the implementation of optical fiber devices, which have gained recently an increased popularity in commercial instrumentation, allow to carry the excitation light from the source to the sample, and to collect the emission). 

Sakka S. Fibers from Gels and their Application. In Glass Integrated Optics and Optical Fiber Devices, Critical Review of Optical Science and Technology Vol CR53, S.I. Najafi, ed. Published by SPIE, 1994, pp. 114-131... 

The iavention of the laser ia 1958 prompted the beginning of the story of optical fiber communications. This device was capable of produciag a high iatensity, coherent beam of light which could be modulated at a high rate (see Lasers). StiU, no transmission medium of suitable clarity was available. 

TaF has been characterized by ir, Raman, x-ray diffraction, and mass spectrometry (3,11,12). TaF has been used as a superacid catalyst for the conversion of CH to gasoline-range hydrocarbons (qv) (12) in the manufacture of fluoride glass and fluoride glass optical fiber preforms (13), and incorporated in semiconductor devices (14). TaF is also a catalyst for the Hquid-phase addition of HF to polychlorinated ethenes (15). The chemistry of TaF has been reviewed (1,16—19). Total commercial production for TaF is thought to be no more than a few hundred kilograms aimuaHy. 

GaUium-based laser diodes have also lost some of the market in telecommunications to indium-based devices. Optical fiber systems moved to the use of longer wavelengths for long distance networks. 

Eig. 5. Schematic diagrams of small emission area LED chip stmctures. (a) Cross section of a surface-emitting LED which typically possesses a 20—60 )Tm diameter emission area for coupling to optical fibers, (b) An edge-emitting device which generally possesses a smaller (3—5 )Tm) emission width and is... 

Pigure 10 shows the typical commercial performance of LEDs used for optical data communication. Both free-space emission and fiber-coupled devices are shown, the latter exhibiting speeds of <10 ns. Typically there exists a tradeoff between speed and power in these devices, however performance has been plotted as a function of wavelength for purposes of clarity. In communication systems, photodetectors (qv) are employed as receivers rather than the human eye, making radiometric power emitted by the devices, or coupled into an optical fiber, an important figure of merit. 

Generally, these exists a tradeoff between speed and output power in these devices. The data for fiber-coupled devices are based on emission into a 50/125-//m fiber, except for AlGalnP which is for 1-mm plastic optical fiber coupling. 

Lithium Niobate. Lithium niobate [12031 -64-9], LiNbO, is normally formed by reaction of lithium hydroxide and niobium oxide. The salt has important uses in switches for optical fiber communication systems and is the material of choice in many electrooptic appHcations including waveguide modulators and sound acoustic wave devices. Crystals of lithium niobate ate usually grown by the Czochralski method foUowed by infiltration of wafers by metal vapor to adjust the index of refraction. 

A high temperature optical fiber thermometer has beea developed (32,33). It coasists of a sputtered iridium blackbody tip oa a single crystal sapphire laser. Such a device has beea showa to be accurate to within 0.03° C at 1000°C. 

Optical fiber cables and fiber optic devices approved as an intrinsically safe system suitable for the hazardous (classified) location involved shall be installed in accordance with Sections 504-20 and 770-52. 

Exception Optical fiber cables or fiber optic devices that are conductive shall be installed in accordance with Articles 500 through 503. 

Generating tubes and downcomers entering and leaving the top drum should be inspected either visibly or via the use of an optical fiber camera or video device (fiberscope, e.g., Boroscope ) for signs of corrosion or deposition. 

Light wave technologies provide a number of special challenges for polymeric materials. Polymer fibers offer the best potential for optical communications in local area network (LAN) applications, because their large core size makes it relatively cheap to attach connectors to them. There is a need for polymer fibers that have low losses and that can transmit the bandwidths needed for LAN applications the aciylate and methacrylate polymers now under study have poor loss and bandwidth performance. Research on monomer purification, polymerization to precise molecular-size distributions, and weU-controlled drawing processes is relevant here. There is also a need for precision plastic molding processes for mass prodnction of optical fiber connectors and splice hardware. A tenfold reduction in the cost of fiber and related devices is necessaiy to make the utilization of optical fiber and related devices economical for local area networks and tlie telecommunications loop. 

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