Laser-Assisted Fabrication of Highly Precise 2D Fiber Collimator Arrays

摘要

A lot of applications in optical communication systems require the parallel transmission of several high bit rate data channels based on single mode fibres. For this purpose compact two dimensional fibre collimator arrays can be used. A main quality characteristic for such arrays is the pointing accuracy, which determines the angular deviation of the collimated beams to a theoretical optical axis. This angular deviation is mainly caused by a lateral offset of the fibre axes to the axes of the corresponding micro lens. We examined a laser based micro alignment technology in order to minimize the lateral offset after assembly. The optical fibres are fixed within actor elements of specific geometrical shape. The actor elements are designed according to thermo-mechanical FE-simulations. It is shown that an alignment accuracy within the submicron range can be realized which guarantees a pointing accuracy below 0.01 degrees. The simulations show the influence of different laser parameters on the accuracy and the process times. Experimental results confirm the predicted actor behaviour and demonstrate the feasibility of laser based micro alignment of fibres for the assembly of highly precise two dimensional fibre collimator arrays.