A new photolithography based technique to mass produce microlens+fibre based integralfield units (IFUs) for 2D spectroscopy

Abstract

We present a novel photolithography based technique to efficiently fabricate microlens-fibre based Integral Field Units (IFUs). These IFUs are being developed for Devasthal Optical Telescope Integral Field Spectrograph (DOTIFS) which offer sixteen deployable IFUs. In each IFU, a 12 x 12 microlens array is matched with a similar array of fibres to better than +/- 5 micron accuracy for each microlens-fibre pair in the array. A mask created on copper foils using photolithography, transfer the pupil spot pattern of each microlens array to a fibre array holder. The approach can be used for mass production of IFUs in an extremely efficient and cost-effective manner.