Advancements in Microlenses and their Diverse Applications in Optical Sensors

Abstract The fabrication and characterization are two areas where the microlenses have been widely studied. The integration of microlenses into microdevices was the main slingshot to achieve the fabrication of compact optical microsystems with reduced sizes, low-cost and on a reproducible way. The main driver of cost reduction was the use of standard microfabrication techniques found on the microlectronics industry. The actual interest of microlenses is the light gathering/projection and focusing for optimizing the light acquisition/production and thus, to improve the sensitivity/efficiency of optical microsystems either working as sensor or as source. In this context, this paper makes a review of microlenses for application in optical sensors. This review describes fabrication technologies, characteristics and applications of microlenses. This review also gives special emphasis on a case study of polymeric microlenses obtained by thermal reflow and at the same time, it also demonstrates the feasibility to augment light into photodiodes.