Amorphous Si waveguides with gradient refractive index cladding structure are proposed and fabricated using plasma-enhanced chemical vapor deposition method. Compared with 6 dB/cm for ridge waveguide without gradient cladding, the propagation loss of the gradient cladding waveguides is less than 1 dB/cm with both TE and TM polarizations.
© 2012 Chinese Optics Letters
Weibin Qiu and Jiaxian Wang, "Low-loss amorphous Si waveguides with gradient refractive index cladding structure," Chin. Opt. Lett. 10, 041601- (2012)