The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 07, 1999
Filed:
May. 14, 1997
Chih-Kung Lee, Taipei, TW;
Giin-Yuan Wu, Taipei Hsien, TW;
Wen-Jong Wu, Chungho, TW;
Kun-Sheng Yeh, Taipei, TW;
Chin-Fa Lee, Taipei, TW;
AHEAD Optoelectronics, Inc., Taipei, TW;
Abstract
An interference apparatus is disclosed wherein the high-visibility quadrature interference signals are obtained by making a pair of polarization beamsplitter, a 45-degree oriented quarter-waveplate and four light-beam detected photodiodes. A three-dimensional interference optical configuration is made. The test-surface light beam and reference light beams are traveled on this optical configuration. The test-surface light beam and reference light beams have orthogonally linearly polarization state with each other. After they pass through the quarter-waveplate, one right circularly polarized light beam and one left circularly polarized light beam are produced. The vector sum of these two circularly polarized light beams is again a linearly polarized light beam which is then divided into two light beams by a non-polarization beamsplitter. A pair of polarization beamsplitters, whose axes are 45 degrees apart, are utilized to create the 90 degrees phase difference of the light beam intensity signal measured at the photodiodes.