High-Q Fabry-Pérot Cavity Based on Micro-Lens Array for Refractive Index SensingOAEI

Fabry-Pérot(FP)microcavities have attracted tremendous attention in recent years due to their favorable optical characteristics of the high quality(Q)factor and small mode volume.In this work,we presented a novel approach that utilized the soft lithography and imprinting technology to incorporate the convex micro-lens array structure into the FP(FP-lens)cavity.A strong mode-profile restriction of the micro-lens simultaneously reduced the mode volume and enhanced the Q factor,exhibiting high tolerance to non-parallelism of mirrors compared with that of the plane-plane FP(PP-FP)microcavities.In the experiment,the Q factor of the FP-lens cavity was measured to be 8.145×104,which exhibited a 5.6-fold increase than that of the PP-FP cavity.Furthermore,we experimentally measured the refractive index sensing performance of the FP-lens cavity with the sensitivity of 594.7 nm/RIU and a detection limit of 4.26×10-7 RIU.On the basis of this superior sensing performance,the FP-lens cavity has the great potential for applications in biosensors.