Title :
Pseudoreversibility condition for minimizing radiation loss at discontinuities of coupled waveguides
Author :
Ramadan, Tarek A. ; Cohn, Robert W.
Author_Institution :
Nanotechnology Center, Univ. of Louisville, KY, USA
Abstract :
A design condition is derived for lossless discontinuities of coupled waveguides by finding solutions, which satisfy time reversibility of guided modes. The derived condition is used as a bound for minimizing radiation loss. Even when there is strong coupling between guided modes, the radiation loss can be minimal. A comparison between different grating designs in a 2 /spl times/ 2 backward coupler demonstrates that two coherently coupled gratings can significantly reduce radiation loss, as compared to a single grating.
Keywords :
diffraction gratings; integrated optics; optical couplers; optical design techniques; optical losses; optical waveguide theory; backward coupler; coupled gratings; coupled waveguide discontinuities; design condition; grating designs; guided modes; integrated optics; lossless discontinuities; pseudoreversibility condition; radiation loss; strong coupling; Gratings; Nanotechnology; Optical coupling; Optical losses; Optical scattering; Optical waveguides; Particle scattering; Reflection; Transmission line matrix methods; Waveguide discontinuities;
Journal_Title :
Photonics Technology Letters, IEEE
DOI :
10.1109/LPT.2002.805763
