Characterization studies of photonic wire bonding for fiber array integration

Photonic wire bonding (PWB) is an advanced packaging technology that addresses key challenges in traditional photonic interconnects. Instead of relying on precise active alignment techniques using grating couplers or butt-coupled facets, PWB uses two-photon polymerization to integrate photonic devices with low transmission loss. In this paper, we present studies on the offset and misalignment of PWBs when used to connect fiber arrays. We examine the effects of horizontal and/or vertical offsets of the PWB, which require bending the PWB horizontally and/or vertically, and which influence the PWB's loss characteristics. We evaluate the misalignment tolerances of the input fiber relative to the PWB core and analyze their impact on loss. Our study presents both theoretical and experimental analyses of the loss properties of fiber-integrated PWBs under varying offset conditions. The average experimental loss for fiber-PWB-fiber connections is approximately 1.41 dB when the PWB is straight, with no bends. When horizontal and vertical offsets of 20 µm and 10 µm, respectively, are introduced, the loss increases to 2.92 dB. Additionally, we examine the power-handling capabilities of PWBs to evaluate how high optical power affects their performance and durability for use in integrated photonic systems.