A Real Time Precision Measurement Technique for Low Loss Optical Polymeric Waveguide

Optical polymer waveguide is a key passive component for the optical interconnection. Design and fabrication of high performance waveguides has a critical importance for the success of optoelectronic integration. We present here a fast, non-destructive, sensitive, and real-time technique for detailed investigation of the propagation properties of planar optical waveguides. We use this technique to have demonstrated high performance polymer waveguides on PCB substrates with propagation loss less than 0.05 dB/cm. To the best of our knowledge, this was in the lowest loss date range reported for polymer waveguides on PCB substrates to date. A high sensitive CCD camera with a built-in integration function is utilized to observe the light streak in two dimensions through a two lens imaging system. A few seconds to a few ten seconds depends on the beam scattering intensity is needed for complete one measurement, compared to the sliding prism method requiring several hours and cutback method requiring even longer time. This technique can not only be used to evaluate the overall performance of a waveguide but also local waveguide performance and in-situ investigation of the propagation properties (defect effect, mode profile, bending properties, etc.). It can be extended to monitor the process of waveguide fabrication and alignment control during the assembly for the optical circuit integration.