Abstract: Non-iterative techniques for phase retrieval for estimating errors of an optical system. A method for processing information for an optical system may include capturing a focused image of an object at a focal point (110), capturing a plurality of unfocused images of the object at a plurality of defocus points respectively (110), processing at least information associated with the focused image and the plurality of unfocused images (120 and 130), and determining a wavefront error without an iterative process (140). In addition, a non-iterative system (400) capable of processing image information is also provided.

Abstract: Glints (e.g., images of point sources attributable to specular reflections) are suppressed in the focal plane of an optical imaging system by:a) Fourier-transforming an image of the imaging system's object field (including glints), and dividing the resulting energy distribution into a first channel and a second channel;b) focussing the energy in the first channel onto a first diffraction grating so as to impose a periodic carrier on the image, thereby producing a first image signal;c) directing the energy in the second channel so as to illuminate a Fourier-transform hologram of the complex point response of the imaging system to which additional aberrations (preferably toroidal aberrations) have been added;d) focussing the energy distribution from the hologram onto a second diffraction grating that is 180.degree. out-of-phase with the first diffraction grating, and blocking higher diffracted orders, thereby producing a second image signal;e) superimposing the first and second image signals (which are 180.

Abstract: A semiconductor laser diode in which oblate-spheroidal modes are established to enhance emitted beam characteristics. The laser diode laser cavity ends are configured in the shape of Fresnel lenses.