GRIN-lens based optical interconnection systems for planes of micro emitters and detectors: Microlens arrays improve transmission efficiency

Abstract

There has recently been significant progress in the development of arrays of fast and sensitive optoelectronic emitters, detectors and transceiver devices. If arrays of these devices are to be successfully incorporated into switching fabrics, data communication or information processing systems, then highly efficient optical systems must be developed to interconnect them. It is indeed important to minimise transmission losses, because the bandwidth of such data channels strongly depend on the amount of optical power impinging on the receivers. The highly divergent nature of some of these sources, such as Lambertian emitters and microcavity LEDs, does not facilitate this task, because of the high insertion losses at the input of the optical system. Moreover we want these systems to be compact, low cost, robust and easily assembled. In this paper we present a novel, hybrid and compact optical system, based on large diameter radial gradient refractive index (GRIN) lenses and microlenses that fulfills these requirements. We also model this system with raytracing software and evaluate its performances experimentally.