Thermo Optical Properties of 3D Photonic Wire Bonding Connecting Silicon Nitride Waveguides

This paper investigates the thermo-optical (TO) effect of misaligned polymer wire bonds (PWB) connecting planar silicon nitride waveguides. To characterize the fabricated devices, we measured the optical transmission through PWBs by changing the chip temperature in the range from 30°C to 80°C. We used an experimental setup, which included a tunable laser source in the 1510-1620 nm range and a changeable temperature stage. By gradually changing the temperature of the sample, we measured the transmission parameter through the reference arm and the arm with PWB. We found that the TO coefficient equals 837 pm/°C, respectively, with the change resonance wavelength. The results can be used to design complex optical interconnections inside and between chip and show the thermal stability of such interconnection.