Progress In Electromagnetics Research
ISSN: 1070-4698, E-ISSN: 1559-8985
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By A. A. Ehsan, S. Shaari, and M. K. Abd-Rahman

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An optical code generating device has been developed based on 1×2 and 1×4 asymmetric plastic optical fiber (POF) couplers. The code generating device provides a unique series of output power which are successively used as an optical code in a portable optical access-card system. The system is designed where the asymmetric POF coupler is embedded in an all passive portable unit. This device utilizes a tap-off ratio (TOFR) technique based on a simple variation of the tap width of an asymmetric Y-branch splitter design. A hollow-type waveguide structure is used where it eliminates the use of polymeric material for the waveguide core and allows simple fabrication and assembling of the device. The asymmetric POF coupler has been fabricated on metal-based materials using machining technique. The results for the simulated and fabricated 1×2 asymmetric couplers show the same linear characteristics between the TOFR and the tap width. The simulated devices shows a TOFR variation from 18.6% to 49.9% whereas the TOFR for the fabricated metalbased devices varies from 10.7% up to 47.7%, for a tap width of 500 um to 1 mm. The 1×4 coupler designed using simple cascading of a Y-branch splitter with two 1×2 asymmetric couplers has been fabricated and shows similar characteristics as that of the designed 1×4 devices. The insertion loss for the 1×2 asymmetric coupler at the tap line varies from 9 dB to 16 dB whereas for the bus line, the insertion loss is about 9±0.8 dB. The insertion loss for the 1×4 asymmetric coupler at the output ports varies from 14 dB to 22 dB.

A. A. Ehsan, S. Shaari, and M. K. Abd-Rahman, "Metal-based 1×2 and 1×4 asymmetric plastic optical fiber couplers for optical code generating devices," Progress In Electromagnetics Research, Vol. 101, 1-16, 2010.

1. Zubia, J. and J. Arrue, "Plastic optical fibers: An introduction to their technological processes and applications," Optical Fiber Technology, Vol. 7, 101-140, 2001.

2. Kalymious, D., Plastic Optical Fibres (POF) in sensing --- Current status and prospects, 17th International Conference on Optical Fibre Sensors, Proc. SPIE, Vol. 5855, 1-4, 2005.

3. Buckley, N. I., Codeable card and card-reading apparatus thereof, UK Patent 2022300, May 10, 1979.

4. Borough, H. C. and D. A. Pontarelli, Encoded card employing fiber optic elements, US Patent 3728521, April 17, 1973.

5. Gary, C. K. and M. Ozan, Security system responsive to optical fiber having Bragg gratings, US Patent 5633975, May 27, 1997.

6. Defense and Nuclear Technologies and Engineering Directorate, "Putting thieves on notice," Science and Technology Review, 4-5, Lawrence Livermore National Laboratory, October 1998.

7. Ehsan, A. A., S. Shaari, M. K. Abd Rahman, and K. M. R. Kee Zainal Abidin, "Hollow optical waveguide coupler for portable access card system application," Journal of Optical Communications, Vol. 30, 67-73, 2009.

8. Henry, W. M. and J. D. Love, "Asymmetric multimode Y-junction splitters," Journal of Optical and Quantum Electronics, Vol. 29, No. 3, 379-392, 1997.

9. Nubling, R. K. and A. J. Harrington, "Launch conditions and mode coupling in hollow-glass waveguides," Opt. Engineering, Vol. 37, No. 9, 2454-2458, 1998.

10. Ziemann, O., J. Krauser, P. E. Zamzow, and W. Daum, POF Handbook: Optical Short Range Transmission System, Springer-Verlag, 2008.

11. Ehsan, A. A., S. Shaari, and M. K. Abd Rahman, "1 £ 2 Y-£ branch plastic optical fiber waveguide coupler for optical access-card system," Progress In Electromagnetics Research, Vol. 91, 85-100, 2009.

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