Abstract: Fourier Transform Spectroscopy is performed using a birefringent device to vary path difference systematically for all regions of an image simultaneously, so that a separate interferogram is collected for each image region by combining intensity values in multiple images. The optics may allow a theoretical efficiency of 100% in light throughout.

Abstract: An endoscope system is provided with first and second light guides, which are optically coupled by an optical coupler. A low-coherent light source is provided, and the light emitted therefrom is incident on the first or second light guide. Further provided is a scanning unit that causes the light beam emerged from the first light guide to scan on a predetermined surface of the object. The light beam reflected by the object is directed, by the scanning unit, to the first light guide as a detection light beam. A light beam emerged from the second light guide is reflected by a reflector and returned to the second light guide as a reference beam. By varying the optical path length of the reference beam relative to that of the detection beam, two beams interfere. A signal processing system generates OCT image based on the signal detected by a light detecting device which receives the interfering beams.

Abstract: A paper classification apparatus includes a heater for heating paper or a solvent supply unit for supplying a solvent to the paper, a detector, a computer, and a selector guide. The detector detects the reflection density of the paper after being heated or supplied with the solvent. The computer compares the detected reflecting density of the paper with a predetermined reference value stored in a memory. The selector guide classifies the paper on the basis of a comparison result of the reflection density. This apparatus can classify plain paper having an image formed with an ordinary image forming material, plain paper having an image formed with an erasable image forming material, and thermosensible paper.

Abstract: Wavefront information for an optical system is calculated based on the intensity of an image of a plurality of gratings having different periods and orientations taken from at least two different planes a predetermined distance apart. The image of a plurality of gratings having different spatial frequencies or periods and orientations, the location of which are precisely known, are imaged in a nominal focal plane of the optical system, and, preferably, in two additional planes displaced a predetermined distance from the nominal focal plane. The phase shift, if any, from a fundamental frequency of the image intensity, is determined based on the known location of the grating and the grating image intensity. The grating image intensity is detected and measured in a first detection plane in a nominal focal plane and in a second detection plane a predetermined distance from the nominal focal plane. From these measurements wavefront information is calculated.

Abstract: An apparatus incorporated within a spectroscopic imaging system, typically a microscope, but also applicable to other image gathering platforms, namely fiberscopes, macrolens imaging systems and telescopes employing a polarizing beam splitting element is disclosed. The apparatus allows simultaneous spectroscopic (i.e. chemical) imaging and rapid acquisition spectroscopy to be performed without the need for moving mechanical parts or time sequenced sampling and without introducing significant optical signal loss or degradation to the spectroscopic imaging capability. In addition, the apparatus affords a more compact design, an improved angular field of view and an improved overall ruggedness of optical design at a lower manufacturing and maintenance cost compared to previous devices.

Abstract: A method of unambiguous range estimation is provided for use with a range imaging system that derives phase images from image pixels of a digital image. The method involves generating (a) a first phase image having one or more ambiguous phase intervals and (b) at least one additional phase image that is generated by shifting the phase intervals of the first phase image. Then at least one region of intersection between phase intervals in the two phase images is identified. Finally, the phase of at least one of the ambiguous phase intervals in the first phase image is adjusted based on values of the phase of the image pixels that belong to the region of intersection. As a result, the phase adjustment unwraps the phase ambiguity in the phase intervals of the first phase image.

Abstract: The correction method of the invention synthesizes a distortion-free interferogram (or spectrum) from a measured interferogram, which has been distorted by detector non-linearities, and a finite series of orthogonal functions derived therefrom. The coefficients of the series of functions are selected with a priori knowledge about the limited spectral sensitivity of the radiation detector, preferably with the method of Gaussian least squares fit of observation, such that the resulting spectrum assumes the value of zero of the distortion-free spectrum outside of the sensitivity range, and in freely-definable ranges. The method of the invention can be used to correct detector non-linearities, as occur in Fourier spectroscopy.