Wavelength tunable photon source with sealed inner volume

A wavelength tunable photon source comprising

• a first element comprising a first mirror,
• a second element comprising a second mirror, and
• a third element comprising a photon emitter,
• where the first element and the second element and the third element are placed in relation to each other, so that
• i. the first mirror and the second mirror define at least a part of an optical cavity, and so that
• ii. the photon emitter is placed inside the optical cavity,
• where at least the first element and the second element and the third element are joined together, in a coherent structure enclosing a inner volume being a sealed volume, and
• where the coherent structure comprises a bonding interface adjacent to the inner volume, which bonding interface is gas-tight, abutting on a first side the first element and on a second side the third element,
• wherein
• the first mirror is placed in the inner volume so that the first mirror may move within the inner volume and where at least a portion of the inner volume is placed on a side of the first mirror facing the optical cavity and where at least a portion of the inner volume, is placed on an opposite side of the first mirror, and wherein the wavelength tunable photon source further comprises an electrical, piezo-electrical, thermal or mechanical actuator that is configured to move the first mirror within the inner volume.