Optical projector with beam monitor including sensing intensity of beam pattern not projected toward an object

Optical apparatus, comprising:na device package;a radiation source, contained in the package and configured to emit a beam of coherent radiation;a diffractive optical element (DOE), mounted in the package so as to receive and diffract the radiation from the radiation source into a predefined pattern comprising multiple diffraction orders that are projected from the package toward an object; andan optical detector, which is positioned in the package so as to receive and sense an intensity of a portion of the pattern that is produced by the DOE but is not projected toward the object.

An optical method, comprising:ntransmitting a beam of coherent radiation through a diffractive optical element (DOE), mounted in a package, so as to diffract the radiation into a predefined pattern comprising multiple diffraction orders that are projected from the package toward an object; andmonitoring a performance of the DOE by sensing, using an optical detector positioned in the package, an intensity of a portion of the pattern that is produced by the DOE but is not projected toward the object.