Abstract: A phase conjugate interferometer includes a laser light source, an optical lens (through which the laser beam is diverged) disposed at the end of the optical fiber, a paraboloidal mirror surface to be tested which reflects the laser beam diverged by the objective lens, a semi-transparent mirror disposed between the objective lens and the paraboloidal mirror surface for transmitting the laser beam from the objective lens to the paraboloidal mirror surface, a light reflection portion having both a parallel plane glass plate with a reference flat surface and a non-linear optical crystal for causing a phase conjugate wave front, and a screen. The light reflection portion reflects the incident laser beam reflected by the paraboloidal mirror surface as two laser beams, one with a reference flat surface and the other with a phase conjugate wave front caused by the non-linear optical crystal.

Abstract: An optical nondestructive testing method of composite materials utilizes optical interferometry to find the resonant vibration from at least one surface of the target part of an object being inspected, and also determines the resonant frequency at that time. Another resonant frequency exhibiting the same resonant vibration is then obtained from the rear surface of the part of the object being inspected and the two resonant frequencies are used to derive the depth of defects in the object.

Abstract: An interference method of testing the surface precision of a parabolic mirror comprising the steps of dividing a beam of light rays into two beams, converting these beams into divergent spherical light waves by means of microscope object lenses, illuminating the parabolic mirror with one of the divided beams of light rays, producing a standard light from the other divided beam of light rays, and causing the reflected light from said parabolic mirror to interfere with the standard light.

Abstract: High-precision turning of a metal mirror is accomplished by causing a measuring beam to be reflected on a freshly turned area of the reflecting surface to be formed in a metal blank being turned to produce a metal mirror and, at the same time, causing reference beams to be reflected on areas turned prior to the aforementioned freshly turned area, measuring the positions of incidence of the resultant reflected beams on a position detection device thereby performing the Hartmann test on the aforementioned turned areas of the reflecting surface and, based on the results of the measurement, controlling the nose position of the cutting tool now being used in turning the reflecting surface.

Abstract: A holographic straightness meter comprising an optical element and a hologram disposed on a moving member and one pair of reflection elements disposed on a fixed member. The object beam and reference beam from the optical element are reflected by the reflection elements so as to impinge upon the hologram and form interference fringes on the screen placed behind the hologram. The number, interval, and inclination of these interference fringes vary with the amount of lateral displacement of the moving member. Thus by analyzing the interference fringes for such factors, the amount of the lateral displacement of the moving member can be determined.