Dynamical fabry-pérot tuneable filter device

摘要

The present invention comprises a Fabry-Pérot tuneable filter device with a first and a second reflecting element (48, 46) separated by an optical path length to form an optical resonator cavity (56), and a first actuator means (50). Said first actuator means is directly coupled with said first reflecting element, or indirectly coupled with said first reflecting element via a supporting member supporting said first reflecting element. Herein, the first actuator means is configured to modulate the optical path length between said first and second reflecting elements by a modulation amplitude to thereby sweep the optical resonator cavity through a band of optical resonance frequencies with a sweep frequency of 70 kHz or more, preferably 100 kHz or more and more preferably 200 kHz or more. Further, the tuneable Fabry-Pérot filter device is characterized by one or both of the following features: (a) the mechanical coupling between at least two elements out of the first actuator means, the first reflecting element and the supporting member is sufficiently low such that said at least two elements when operated at said sweep frequency of 70 kHz or more act as a system of coupled oscillating elements; (b) the first actuator means is directly coupled with or indirectly coupled with said first reflecting element via said supporting member such as to substantially drive the first reflecting element only. In one embodiment, the FP-TF device is a tuneable VCSEL having a gain medium that is provided in the resonator cavity.