Optimization of waveguide photodetector with thin absorbing layer and large responsivity

We present optimized structure of waveguide photodetector (WGPD) having large responsivity in spite that its absorption layer is thin. Through beam-propagation method simulations, spot-size converter integrated WGPD is found to be able to have larger responsivity with thinner absorbing layer. Calculated responsivity and polarization dependent loss of the optimized design are 0.83 A/W and 0.13 dB with 150-nm-thick and 25-μm-long absorber.