ACTIVE ALIGNMENT OF REPLICATED MICROLENS ARRAYS ON A CHARGE-COUPLED-DEVICE IMAGER

A hybrid microlens/aperture mask assembly is fabricated, aligned and m ounted on a CCD imager for an application in an imaging polarimeter. T he microlens array is produced by direct laser writing in photoresist followed by electroforming and replication onto a glass substrate in r egistration with a slit aperture array on the reverse side. An alignme nt of the combined arrays to the CCD imager of better than 0.7 mu m in lateral position and 0.005 deg rotation is achieved, Stray light of l ess than 1% was measured for the hybrid module. The optical microsyste m satisfied the challenging requirements of the imaging polarimeter an d the technique has applications in other areas of optical sensing, me trology and processing. (C) 1997 Society of Photo-Optical Instrumentat ion Engineers.