Environmental Stress Testing of Electro–Optic Polymer Modulators

Low V_pi electro-optic (EO) polymer modulators were environmental stress tested at both the chip and packaged device level. Different top clad materials showed different results for high-temperature and temperature cycle testing, which is related mostly to coefficient of thermal expansion (CTE) mismatches and/or adhesion properties of the clads related to other materials in the devices stack and to the substrate and electrode materials. With thoroughly compatible cladding, devices that are thermally stable for over 5000 h at 85degC have been achieved. High optical power ( 500 mW @ 1550 nm) tests showed the photochemical stability of the EO polymer material in hermetically sealed packages. The results demonstrate that clad polymers and interactions between devices layers are of concern for achieving environmentally stable EO polymers modulators.