Micromechanical tunable fabry-perot interferometer and a method for producing the same

An electrically tunable Fabry-Perot interferometer, comprising

• a substrate,
• a first mirror on the substrate,
• a second, movable mirror,
• the second mirror has a movable optical area and a movable area surrounding the optical area,
• a Fabry-Perot cavity between the first and second mirrors,
• the first and second mirror have electrodes for electrical control of the distance between the mirrors,
• at least the surrounding area of the second mirror has a gap between two layers of the mirror, and mirror layers at the opposite sides of the gap are connected with anchoring through the gap,
• characterised in that
• the electrodes of the first and second mirrors extend to the optical area, and
• the implementation of the anchoring is such that the stiffness of the surrounding area is lower than the stiffness of the optical area, whereby the movable mirror is arranged to bend more at the surrounding area than at the optical area on activation of the electrodes with a control voltage.

Method for producing an electrically tunable Fabry-Perot interferometer, wherein

• a substrate is provided,
• a first mirror is provided on the substrate,
• a second, movable mirror is provided, wherein the second mirror has a movable optical area and a further movable area surrounding the optical area,
• a Fabry-Perot cavity is provided between the first and second mirrors,
• electrodes are provided for the first and second mirrors for electrical control of the distance between the mirrors,
• a gap is provided between two layers of the mirror in at least the surrounding area of the second mirror, and anchoring is provided for connecting mirror layers at the opposite sides of the gap with the anchoring through the gap,
• characterised in that
• the electrodes of the first and second mirrors are formed to extend to the optical area, and
• the anchoring is such implemented that the stiffness of the surrounding area is lower than the stiffness of the optical area, whereby the movable mirror is arranged to bend more at the surrounding area than at the optical area on activation of the electrodes with a control voltage.