Simulated fabrication of off-axis microlens array using excimer laser dragging process

A computer simulation of the fabrication of an off-axis aspheric microlens array using excimer laser dragging with variously shaped masks is performed. Traditionally, a semicircular mask is used during dragging to yield an on-axis microlens array. However, a quarter-circular mask can generate an off-axis microlens array using this dragging process. Unlike the more common centered or on-axis system, this off-axis microlens array can process focused light without obstructing the lens. Variously shaped masks were computer simulated. The results indicate that, in laser dragging, the shape of the mask decides the form accuracy for both the on-axis and off-axis microlens. Additionally, a parabolic mask provides excellent axial symmetry. This new process combines the advantages of good axial symmetry and a full fill factor in fabricating an off-axis aspheric microlens array.