Abstract: A coherent imaging system for producing high resolution images is provided. A coherent radiation source module produces two radiation beams, each at a different instance. An optical component directs the first radiation beam towards a target at a first angle to produce a first return beam, and also produces a first reference beam. Another optical component directs the second radiation beam towards the target at a second angle to produce a second return beam, and also produces a second reference beam. An aperture collects the first return beam and the second return beam. A detector module produces two coherent images based on interference between the return beams and the reference beams. The detector module also combines the first coherent image and the second coherent image to produce a high resolution coherent image, which has a resolution higher than a resolution of the first coherent image or the second coherent image.

Abstract: A method and apparatus measure the accuracy of and optically calibrate a scan mirror. Both the method and apparatus may operate over a wide range of environmental conditions. The environmental conditions may include variations in pressure from a vacuum to several atmospheres. Similarly, large variations in temperature may be accommodated. The apparatus includes a laser source, a plurality of facet mirrors and a detector. The laser source projects a beam onto a reflective surface of a rotatable scan mirror, which directs the beam to each of the plurality of facet mirrors. Each facet mirror is positioned at a known angle. Each facet mirror in turn reflects the beam from the reflective surface of the scan mirror substantially back onto itself (autocollimation). The angle detector then receives the reflected beam and measures a value related to a return angle of the beam.