Low f-number microlenses for integration on optical microsystems

This work was sponsored by the Brazilian agency Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) under the grant 400110/2014-8: Ciencia sem Fronteiras, Bolsa Pesquisador Visitante Especial (PVE) 2014. The associate editor coordinating the review of this paper and approving it for publication was Prof. M. Nurul Abedin.