Optical couplers

Interference Filters Optical Fibre Optical Coupler... 

Arrayed microlenses are widely used in a variety of applications that involve miniaturized optical components.172 For example, they can be found at the heart of optical communication systems, facsimile machines, laser printers, and many other kinds of digital information storage or processing devices. In all these applications, the arrayed microlenses simply serve as diode laser correctors, fiber-optic couplers or connectors, and optical scanners. In a set of recent publications, Whitesides and coworkers have also demonstrated that arrayed microlenses could be used as a new platform for photolithography, through which submicrometer-sized structures could be conveniently fabricated as patterned arrays by reducing mm to cm scale features on a photomask.157... 

Brandenburg A, Polzius R, Bier F, Bilitewski U, Wagner E (1996) Direct observation of affinity reactions by reflected-mode operation of integrated optical coupler. Sensors Actuators B Chem 30 55-59... 

First X-ray measurements show that the helical superstructure of the cholesteric and chiral smectic C phase can be untwisted by stretching the elastomer (5). High strains of 300% are necessary for this purpose (compared to 20% for the achiral elastomers). Nevertheless these results show that the chiral lc elastomers have the potential to act as mechano-optical couplers (cholesteric phase) or as piezo-elements (chiral smectic C phase) (5), because the mechanically induced change of the helical superstructure has to change the optical transmission or reflection properties or the spontaneous polarization. Both effects however have not yet been measured directly. 

Tazawa H, Kanie T, Katayama M (2007) Fiber-optic coupler based refractive index sensor and its applications to biosensing. Appl Phys Lett 91 113901... 

Spectroscopic techniques are popular as a means of detection on chips. Examples include the determination of flavins and DNA by fluorescence. Spectrophotometric techniques are often used for biological samples . Mass spectrometry has also been used. Benetton et al. coupled electrospray ionisation MS to a chip while Sillon et al. developed a low cost mass spectrometer which incorporated the ionisation chamber, filter and detector on the chip. A fibre optic coupler has been developed as a detector. The dual optical fibre configuration (one transmitting, one receiving, (Eigure 10.5)) in the chip forms the microchannel as well as the detector itself and measures refractive index changes but can also be used to measure absorbance . 

Stadnik, D. and Dybko, A. (2003) Fibre optic coupler as a detector for microfluidic applications. Analyst, 128, 523-526. 

Figure 1. Schematic (a) of the overall fiber optic spectrometer and (b) magnified view of the optical coupler. (Reproduced from ref. 5. Copyright 1986 American Chemical Society.)...

In optical sensing system, it is necessary to employ optical couplers and lenses in order to focus the light beam to the optical fiber and direct radiation from the return fiber to the photodetector. Injecting light from a source into a fiber is a more tedious operation. Laser sources produce a coherent beam of light with a cross-section almost equal to the cross-sectional area of the optical fiber, and, therefore, can be coupled very efficiently to the fiber. On the... 

K. Tiefenthaler Integrated Optical Couplers As Chemical Waveguide Sensors. Adv. Biosensors 2 (1992)261-289. 

Regulating mains and load fluctuations is attained by changing the pulse-duty factor triggering the transistor (VI). Transformers or optical couplers can accomplish... 

Figure 10. Schematic cross section of prototype integrated fiber-optic coupler prepared by photoelectrochemicai etching (after Fig, 1, ref. 23)...

Prucnal, P.R., Possum, E.R. and Osgood, R.M., Integrated fiber optic coupler for very large scale integration interconnects. Optics Letters 11 109-111 (1986)... 

Cross-talk problems are of interest in the design of optical couplers, or... 

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