Abstract: A medical imager, primarily for use in oral and dental applications. The imager has a source for providing a plurality of collimated beams of non-ionizing radiation, in particular near-infrared light, and a plurality of correlated detectors. Each detector is arranged to receive unscattered light from one or part of one of said collimated beams and scattered light from one or more other beams. The imager further comprises means for using both the unscattered and scattered light to form an image.

Abstract: A medical imager, primarily for use in oral and dental applications. The imager has a source for providing a plurality of collimated beams of non-ionizing radiation, in particular near-infrared light, and a plurality of correlated detectors. Each detector is arranged to receive unscattered light from one or part of one of said collimated beams and scattered light from one or more other beams. The imager further comprises means for using both the unscattered and scattered light to form an image.

Abstract: The light emitted by diodes of the Gallium Nitride type which comprises two distinguishable emissions is controlled by a single optical element (10) in the form of a lens having a central part and an annular part with different optical powers. The total output light of the diode may be collimated or brought to a common focus. The single optical element is preferably injection moulded and the annular part takes the form of a diffraction lens. The first part (12) is preferably a refractive lens which has a different optical power to the second part (14)which is preferably a diffractive lens. The optical power of the refractive lens (12) (the first optical power) and the optical power of the diffractive lens (14) (the second optical power) are selected to match the light source that the lens (10) is to be used with.