Abstract
There are two ways to significantly reduce modal dispersion in a waveguide: use only single mode waveguides, or use a graded index waveguide. The first choice appears to be the simplest, but it is not always a practical solution. Single mode waveguides are much more difficult to couple light into than multimode waveguides. To help see this, consider the two planar structures shown in Fig.7.1. Both waveguides have the same indexes, but one of them has a larger guiding layer. The number of guided TE modes can be approximated from Eq.2.43
Given identical indices of refraction, the only way to make a waveguide operate in a single mode is to reduce the thickness, h, of the guiding film. The smaller dimension of the single-mode guiding layer makes alignment between sources and other guides much more critical than with a large (multimode) structure. Connecting and aligning between multimode waveguides is easier due to the large size.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
C. R.Pollock, Fundamentals of Optoelectronics, Irwin, USA, (1995)
A. B. Sharma, S. J. Halme, and M. M Butusov, Optical fiber systems and their components, Springer Series in Optical Sciences, vol. 24, Springer, Berlin (1981)
The term Eikonal was introduced by H. Bruns (1895)
H. Kogelnik, in Integrated Optics, Topics in Applied Physics Vol. 7, 2nd edition, T. Tamir, ed.,Springer-Verlag, Germany, (1979)
Richard Crandell, Pascal Applications for the Sciences, John Wiley and Sons, USA (1984)
W. Press, B. Flannery, S. Teukolsky, and W. Vetterling, Numerical Recipes, The Art of Scientific Computing, Cambridge University Press, USA (1986)
Author information
Authors and Affiliations
Rights and permissions
Copyright information
© 2003 Springer Science+Business Media New York
About this chapter
Cite this chapter
Pollock, C.R., Lipson, M. (2003). Graded Index Waveguides. In: Integrated Photonics. Springer, Boston, MA. https://doi.org/10.1007/978-1-4757-5522-0_7
Download citation
DOI: https://doi.org/10.1007/978-1-4757-5522-0_7
Publisher Name: Springer, Boston, MA
Print ISBN: 978-1-4419-5398-8
Online ISBN: 978-1-4757-5522-0
eBook Packages: Springer Book Archive