A Fast and High-precision Alignment Method for IFU Based on Optical Interferometry and Fresnel Diffraction

High-precision alignment between the microlens array and the fiber-positioning microplate is of great significance in developing fiber-based integrated field units (IFU). In this paper, we propose a method combining optical interference and a Fresnel diffraction model to realize fast and accurate alignment. The minimum resolution angles of the tip and tilt in the optical interference-assisted alignment experiment are 2.6 x 10(-4 degrees) and 1.3 x 10(-4 degrees), respectively. The errors in the remaining four degrees of freedom, x, y, z, and roll, are simulated by the Fresnel diffraction model. Finally, the output energy of 96.7% of the number of fibers is within a tolerance error of 10% and the relative energy reaches its highest level, which meets the IFU requirement.