【IEEE Photonics Technology Letters】Elastomeric Microlens Arrays With Tunable Focal Length
writer：Bin Sheng*, He Wu
keywords：Microlens Arrays, Tunable Focal Length, Elastomeric
source：期刊
specific source：IEEE Photonics Technology Letters ,
Issue time：2018年
Microlenses (MLs) and microlens arrays (MLAs) become important optical devices in the fields of sensing, imaging, light source, optical fiber communication, and optical interconnects. In this paper we proposed a new method to fabricate microlens arrays of polydimethylsiloxane (PDMS) with tunable focal length by stretched in radial direction. 3 × 3 PDMS MLAs with positive focal length can be replicated from the PDMS MLAs with negative focal length using evaporated vaseline film as an isolation layer. By tuning the strain of PDMS film in the replication process or the final PDMS MLAs, the focal length of microlenses on MLAs will change accordingly. As a result, the focal length of 3 × 3 PDMS MLAs is tuned from 5.7 mm to 10.6 mm as it is stretched in radial direction from 0% to 15%. Meanwhile, compressed in radial direction from 0% to -15 %, the focal length of PDMS MLAs is tuned from 5.7 mm to 3.4 mm. This technique may have potential applications in the fields of confocal imaging and wavefront sensing.