A 3 Degrees-of-Freedom Electrothermal Micro-Positioner for Optical Chip-to-Chip Alignment

This article proposes an electrothermal three-degrees-of-freedom (3-DOF) micro-positioner equipped with a waveguide path, which can potentially be used for chip-to-chip alignment in photonic integrated circuits. The micro-positioner provides translational displacements along the x-, y- and z- axes with manageable levels of cross-sensitivity between axes. A fabricated prototype provides displacements of <tex-math notation="LaTeX">± 3.35~μ m </tex-math> at 105 mW along the x-axis, and <tex-math notation="LaTeX">+4.5~μ m </tex-math> at 140 mW along the y-axis. Moreover, <tex-math notation="LaTeX">+7~μ m </tex-math> of out-of-plane displacement is achieved along the z-axis when 210 mW is applied to the x-axis actuators to buckle the structure. The AC response of the micro-positioner shows that the fundamental resonance mode occurs at 18.8 kHz. [2023-0208]