Retro-reflective structures

Abstract

A photonic integrated circuit (410) is described comprising at least one signal processing circuit (110). The signal processing circuit (110) comprises at least one input coupling element (120) for coupling incident light from a predetermined incoupling direction into the photonic integrated circuit (410), and at least one output coupling element (130) for coupling light out of the photonic integrated circuit (410) into an outcoupling direction. The relation between the incoupling direction and the outcoupling direction is different from a relation according to the law of reflection and the incoupling direction and the outcoupling direction are substantially the same. Furthermore, an optical sensor probe (400) comprising such a photonic integrated circuit (410) is disclosed. In some embodiments, the optical sensor probe (400) comprises an optical fiber (420) having a first facet and comprises a sensing element physically attached to the first facet, wherein the sensing element comprises said photonic integrated circuit (410).