Abstract
Maximising the optical power collected in a waveguide from the diffracting field of a semiconductor laser is desirable in optical fibre communication systems. However, the spot size and phase front curvature of the laser field usually makes a poor overlap with the mode of the receiving waveguide. Various proposals have been made to improve this coupling. This paper presents the design of a tapered waveguide section, having the correct geometry and refractive index profile, to efficiently capture and transform the rapidly diffracting light from a semiconductor laser to a planar wavefront in a straight waveguide. Experimentally, such an approach requires the refining of available techniques (UV exposure, ion implantation or diffusion) to obtain the required grading of the refractive index profile within the tapered input section of the receiving waveguide.
Similar content being viewed by others
References
Bertilone, D., J. Love and C. Pask. Splicing of Optical Waveguides with Lossless Graded-index Tapers. Opt. Quantum Electronics 20 501–514, 1988.
Brenner, T. and H. Melchior. Integrated Optical Modeshape Adapter in InGa AsP/InP for Efficient Fiber-to-Waveguide Coupling. IEEE Photonics Tech. Letters 5(9) 1053–1056, 1993.
Elyumin, S., K. Komori and S. Arai. GaInAsP/InP Semiconductor Vertical GRIN-Lens for Semiconductor Optical Devices. IEEE Photonics Tech. Letters 6(5) 601–604, 1994.
Ladouceur, F. and J.D. Love. Silica-Based Buried Channel Waveguides & Devices, Chapman and Hall, London, 1996.
Lee, C.-T., M.-L. Wu, L.-G. Sheu, P.-L. Fan and J.-M. Hsu. Design and Analysis of Completely Adiabatic Tapered Waveguides by Conformal Mapping. J. Lightwave Tech. 15(2) 403–410, 1997.
Marcatili, E.A.J. Dielectic Tapers with Curved Axes and No Loss. J. Quantum Electronics QE-21(4) 307–314, 1985.
Marcuse, D. Light Transmission Optics, Van Nostrand Reinhold Company, New York, 1972.
Mersali, B., H.J. Bruckner, M. Feuillade, S. Sainson, A. Ougazzaden and A. Carenco. Theoretical and Experimental studies of a Spot-Size Transformer with Integrated Waveguide for Polarization Insensitive Optical Amplifiers. J. Lightwave Tech. 13(9) 1865–1871, 1995.
Mitomi, O., K. Kasaya and H. Miyazawa. Design of Single Mode Tapered Waveguide for Low-Loss Chip-to-Fiber Coupling. IEEE J. Quantum Electronics 30(8) 1787–1793, 1994.
Mitomi, O. et al. Optical Spot-size Converters for Low-Loss Coupling Between Fibres and Optoelectronic Semiconductor Devices. J. Lightwave Tech. 14(7) 1714–1719, 1996.
Modavis, R.A. and T.W. Webb. Anamorpic Microlens for Laser Diode to Single-Mode Fibre Coupling. IEEE Photonics Tech. Letters 7(7) 63–65, 1995.
Presby, H.M. et al. Laser-to-Fibre Coupling via Optical Fibre Up-Tapers. J. Lightwave tech. 7(2) 274–277, 1989.
Shiraishi, K., N. Oyama, K. Matsumura, I. Ohishi and S. Suga. A Fiber Lens with a Long Working Distance for Integrated Coupling Between Laser Diodes and Single-Mode Fibers. J. Lightwave Tech. 13(8) 1736–1744, 1995.
Snyder, A.W. and J.D. Love. Optical Waveguide Theory, Chapman & Hall, London, 1983.
Spiegel, M.R. Schaum's Outline of Theory and Problems of Complex Variables with an Introduction to Conformal Mapping and its Application, McGraw Hill, New York, 1964.
Tamir, T. (ed.). Guided-Wave Optoelectronics, Springer Verlag, New York, 1990.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ash, A.E., Austin, M.W. & Love, J.D. Efficient coupling of a laser to a waveguide using a taper designed by conformal mapping. Optical and Quantum Electronics 32, 197–208 (2000). https://doi.org/10.1023/A:1007080925215
Issue Date:
DOI: https://doi.org/10.1023/A:1007080925215