A Compact 1310/1550 nm Wavelength Demultiplexer for Passive Optical Network

초록

We designed and fabricated 1310 and 1550 nm demultiplexer with a directional coupler (DC) for passive optical network systems with much increased transmission capacity. We also propose novel design methods to reduce its length and improve its performance. First, the device length was reduced by using the generalized extinction ratio curve. Second, the lateral shift and the curved waveguide for the optimization of input region were adopted to improve the extinction ratio, and the shift is to outward of a directional coupler. Lateral shift reduces discrepancy between the two transfer coefficients. For a given interaction length of 1.948 mm, the 1310 and 1550 nm wavelength light transfer to the cross state and the bar state, respectively. Also, extinction ratios are -28.63 and -19.21 dB at 1310 and 1550 nm, respectively. The demultiplexer was fabricated by the embossing technique.