Optical power meter for safe operation of optical wireless power systems

A system for measuring power of a laser beam, comprising:

• an essentially opaque enclosure, from which the laser beam is directed through an exit aperture open to the outside environment, the enclosure comprising:
• a beam splitter configured to transmit a major part of the laser beam through the exit aperture, and to reflect a minor part of the laser beam;
• a diffuser element positioned such that the reflected minor part of the laser beam impinges thereon;
• at least one detector element in optical communication with the diffuser element, the detector element providing a signal in response to the diffused light of the minor part of the laser beam impinging thereon;
• and
• an absorber element positioned such that light entering the enclosure through the exit aperture, and reflected by the beam splitter, impinges on the absorber element, and is essentially absorbed, wherein:
• the at least one detector element is positioned in a direction optically facing the laser;
• the detector element is aligned such that reflected laser light from the outside environment entering the essentially opaque enclosure through the exit aperture is prevented from impinging on the front surface of the at least one detector element, and
• the detector element is aligned such that stray light from any point in the outside environment entering the essentially opaque enclosure through the exit aperture is prevented from impinging on the front surface of the at least one detector element.