Combining front and back grating structures for broadband absorption enhancement in thin-film silicon solar cells

We investigate the possibilities of enhancing absorption in thin-film silicon solar cells with grating structures on the front ITO and back Ag contacts simultaneously. Broadband enhancement from complementary effects of each grating is demonstrated

Self-pulsing and chaos in short chains of coupled nonlinear microcavities

We examine time-domain instabilities in short chains of coupled Kerr-nonlinear resonators. We show that a large parameter region of self-pulsing or chaotic behavior can be realized. We give a detailed description of the possible states in systems with two and three cavities, using phenomenological coupled-mode equations and rigorous simulations. A particular geometry can exhibit a rich range of dynamics, dependent on input conditions. A clear link with the linear transmission properties is shown. This system complements the studies of the nonlinear Bragg reflector and electrons in a nonlinear lattice. Unlike the Bragg grating case, we observe wide detuning ranges that exhibit self-pulsing without first going through a bistable transition