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Applied Optics

Applied Optics


  • Vol. 36, Iss. 27 — Sep. 20, 1997
  • pp: 6822–6827

Single-mode fiber–linearly tapered planar waveguide tunable coupler

Alok K. Das and Anwar Hussain  »View Author Affiliations

Applied Optics, Vol. 36, Issue 27, pp. 6822-6827 (1997)

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We developed a simple system of tunable fiber–film coupler using a linearly tapered thin-film planar waveguide (PWG) evanescently coupled by a single-mode distributed fiber half-coupler. We investigate the characteristics of the coupler theoretically and experimentally taking into consideration the refractive index (nf) of nonuniform films, the magnitude of nonuniformity (m) of the films, and the source wavelength (λ). The thickness variation of the nonuniform film is along the direction of propagation of optical power. Tapered and plano–concave thin films of a mix of oils as well as a plano–concave poly(methyl methacrylate) film were fabricated to serve as nonuniform PWG’s. Similar to single-mode fiber with a uniform thickness PWG coupler, such a coupler also provides light modulation with a change of nf. However, position shifting of a half-coupler in a tapered PWG structure along the direction of propagation exhibits the variation of fiber throughput power. This action serves as a simple system for a tunable fiber–film coupler. Wavelength-dependent throughput fiber power for such a coupler also behaves as a filter. The center wavelength can be controlled by shifting the position of the half-coupler. A coupling fiber as a half-coupler can be used for efficient coupling. We performed a theoretical analysis of the structure using Marcuse’s model and observed good agreement with the experimental results.

© 1997 Optical Society of America

Original Manuscript: December 4, 1995
Revised Manuscript: October 11, 1996
Published: September 20, 1997

Alok K. Das and Anwar Hussain, "Single-mode fiber–linearly tapered planar waveguide tunable coupler," Appl. Opt. 36, 6822-6827 (1997)

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  1. R. Blue, I. S. Mauchline, G. Stewart, “Applications of sol-gel films in optical waveguide filters,” Electron. Lett. 30, 402–403 (1994). [CrossRef]
  2. Y. Cai, T. Mizumoto, Y. Naito, “An effective method for coupling single-mode fiber to thin film waveguide,” J. Lightwave Technol. 9, 577–583 (1991). [CrossRef]
  3. M. Zhang, E. Garmire, “Single-mode fiber–film directional coupler,” J. Lightwave Technol. LT-5, 260–267 (1987). [CrossRef]
  4. B. L. Booth, “Low loss channel waveguides in polymers,” J. Lightwave Technol. 7, 1445–1453 (1989). [CrossRef]
  5. A. Tz. Andreev, K. P. Panajotov, “Wavelength division action of a distributed single-mode fiber-to-symmetrical planar waveguide coupler,” Photon. Technol. Lett. 6, 1238–1240 (1994). [CrossRef]
  6. A. K. Das, A. K. Mondal, M. K. Pandit, “Effect of liquid on partially removed cladding SM fiber and its application to sensors,” in International Conference on Optical Fibre Sensors in China, B. Culshaw, Y. Liao, eds. Proc. SPIE1572, 572–580 (1991). [CrossRef]
  7. P. K. Tien, R. J. Martin, “Experiments on light waves in a thin tapered film and a new light-wave coupler,” Appl. Phys. Lett. 18, 398–401 (1971). [CrossRef]
  8. H. Kogelnik, “Filter response of nonuniform almost-periodic structures,” Bell Syst. Tech. J. 55, 109–126 (1976). [CrossRef]
  9. C. Liao, G. I. Stegeman, C. T. Seaton, R. L. Shoemaker, J. D. Valera, “Nonlinear distributed waveguide couplers,” J. Opt. Soc. Am. A 2, 590–594 (1985). [CrossRef]
  10. D. Marcuse, Light Transmission Optics, 2nd ed. (Van Nostrand Reinhold, New York, 1982).
  11. A. K. Das, A. K. Ganguly, “Efficient method of coupling from a single-mode fiber to a thin-film waveguide,” Opt. Lett. 19, 2110–2112 (1994). [CrossRef] [PubMed]
  12. D. Marcuse, “Investigation of coupling between a fiber and an infinite slab,” J. Lightwave Technol. 7, 122–130 (1989). [CrossRef]
  13. A. W. Snyder, J. D. Love, Optical Waveguide Theory, 1st ed. (Chapman & Hall, New York, 1983).
  14. A. Tz. Andreev, K. P. Panajatov, “Distributed single-mode fiber to single-mode planar waveguide coupler,” J. Lightwave Technol. 11, 1985–1989 (1993). [CrossRef]
  15. A. K. Das, M. A. Mondal, A. Mukherjee, A. K. Mondal, “Automatic determination of remaining cladding thickness of a single-mode fiber half-coupler,” Opt. Lett. 19, 384–386 (1994). [PubMed]
  16. R. S. Moshrefzadeh, M. D. Radcliffe, T. C. Lee, S. K. Mahapatra, “Temperature dependence of index of refraction of polymeric waveguides,” J. Lightwave Technol. 10, 420–425 (1992). [CrossRef]
  17. J. F. Digonnet, H. J. Shaw, “Analysis of a tunable single mode optical fiber coupler,” IEEE J. Quantum Electron. QE-18, 746–754 (1982). [CrossRef]

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