Reduction of Surface Scattering Loss in Polymer Microrings Using Thermal-Reflow Technique

A thermal-reflow technique is used to greatly reduce surface roughness scattering loss in polymer microring devices. Smoother surfaces were achieved and verified by scanning electron microscopy. Reduction in surface roughness scattering was further supported by the loss measurement of both straight waveguides and microring resonators. The variance of surface roughness in a polymer microring device is estimated to decrease by 35-40 nm after the thermal-reflow treatment, corresponding to a loss reduction of /spl sim/74 dB/cm.