Study of high temperature loading on optical fiber-adhesive bonding

The important design factors that have to be considered for packaging of modules, which have single mode fiber (SMF), are mechanical failure and misalignment of the optical components (such as fiber, lens, laser diode and photo diode) during thermal loading. In this paper, the misalignment of single mode fiber and the strain in the optical module was measured for high temperature loading by Micro Moire interferometry. The experiments were performed on a module consisting of SiOB and single-mode-fiber attached in a V-groove with the help of a UV-curable adhesive. Temperature load ranging from room temperature (23°C) to 100°C was applied to the module. Maximum displacement of fiber in the vertical and horizontal directions relative to the SiOB was determined to be 0.69 - 1.21 μm and 0.36 - 0.42 μm, respectively at 100°C. The variation of the displacement for different samples at a given temperature was observed due to different initial position of fiber in the V-groove and the amount of adhesive around the fiber. Normal strain induced in the fiber was also calculated when the module was subjected to a temperature increment of ~75°C. Finally, a qualitative analysis was carried out for shear strain in different parts of the module and the maximum shear stress was observed at the silicon-adhesive-fiber joint region.