A light wavefront measuring apparatus (2, 2a, 42) includes a separating element (7a, 47a) for separating a flux of light which exits from an optical head (1, 31) into a first beam and a second beam, a first interference fringe display section (21, 21a) for displaying interference fringes formed from the first beam, a Dove prism (13, 53) for rotating a wavefront of the second beam around its optical axis (AX.sub.2), and a second interference fringe display section (22, 22a) for displaying interfe...

A point diffraction interference measuring method comprises forming a substantially ideal spherical wave by using a point light source-generating unit 101, 102, allowing a light flux composed of the spherical wave to pass through a test sample 109, thereafter dividing the light flux into two light fluxes by using an optical path-dividing element 105, allowing one light flux of the divided light fluxes to pass through a pinhole 129 to covert the one light flux into a reference light beam which is...

A wavefront measurement system has a source of electromagnetic radiation. An imaging system focuses the electromagnetic radiation at an object plane. A first grating is positioned in the object plane and has a plurality of rulings with randomized height. A stage moves the first grating parallel to the rulings. A projection optical system projects an image of the first grating onto an image plane. A second grating is at the image plane. A detector behind the second grating receives a fringe patte...

An imaging-type interferometric optical profiler splits a beam reflected from a sample into two beam portions. One portion is a reference beam and the other a sample beam. The reference and sample beams are combined to create interference patterns which are used to obtain a surface profile of the sample. Since vibration of the sample causes the same optical path change, and no reference mirror is used, the interferometric optical profiler is relatively vibration-insensitive and has a fast measur...

An interferometric optical device divides a beam into two beam portions by wavefront division and produces a tunable phase difference between them. Next a sample and a reference reflector reflect the beam portions respectively. Then interference between the reflected beam portions is used for topography, tomography, and readout of multi-layer optical data storage media.

A wavefront measurement system includes a source of electromagnetic radiation. An imaging system directs the electromagnetic radiation at an object plane that it uniformly illuminates. A first grating is positioned in the object plane to condition the radiation entering the input of a projection optic. A projection optical system projects an image of the first grating onto the focal plane. A second grating is positioned at the focal plane that receives a diffracted image of the object plane to f...

By an insertion/withdrawal mechanism, a wavefront division optical element is inserted to an optical path of a light via an optical system to be examined, or the inserted wavefront division optical element is withdrawn from the optical path. Thus, it becomes possible without using a half mirror to make the light via the optical system to be examined be received at a detector via the wavefront division optical element, or the light via the optical system to be examined be received at the detector...

An achromatic shearing phase sensor generates an image indicative of at least one measure of alignment between two segments of a segmented telescope's mirrors. An optical grating receives at least a portion of irradiance originating at the segmented telescope in the form of a collimated beam and the collimated beam into a plurality of diffraction orders. Focusing optics separate and focus the diffraction orders. Filtering optics then filter the diffraction orders to generate a resultant set of d...

The present invention is directed at a coherence test reticle or lithographic plate, and a method for testing the coherence of a laser beam using the test reticle. The quality or coherence of the laser beam is measured by illuminating the test reticle and recording and/or analyzing the optical patterns generated by the illumination. The technique was designed for the characterization of laser-based systems via the detection of optical radiation modulated by transmissive, reflective and diffracti...

A dual sensor wavefront correction system is adaptable to correcting wavefronts including wavefronts that are severely scintillated. The system includes a Hartmann wavefront sensor as well as a unit shear lateral shearing interferometer (LSI) wavefront sensor. The optical output signals from the Hartmann wavefront sensor are applied to a real reconstructor which provides an estimation of the distortion in the wavefront during most conditions except for conditions of severe turbulence. In order t...