New design for low-loss star couplers and arrayed waveguide grating devices

We propose a new loss reduction method in star couplers employing UV-written tapers that replace the free propagation region in the conventional star couplers and apply them to an arrayed waveguide grating (AWG) device. The insertion loss of the new AWG device can be reduced to 0.31 dB, which is about 0.7 dB lower than that of the AWG without UV-written tapered waveguides.