Haruhiko Machida

Endoscopic hologram interferometry using fiber optics.

Basic and practical problems on the formation of fringes in endoscopic hologram interferometry using fiber optics have been studied in connection with medical diagnosis of living body cavities, nondestructive testing of inner parts of machines, etc. It is pointed out that fiber bundles instead of single fibers can be used to transmit high power laser light for object illumination to prevent the light path break induced by the high power density of concentrated laser light. The effects of extended source illumination by the fiber bundle, image transmission through the ordered fiber bundle, and fiber bundle movement on the fringe visibility were investigated.

Point source diffraction and its use in an encoder

Diffraction from a point light source (a laser diode) was studied. The diffraction images were found to be magnified without using a lens and to move corresponding to the displacement of the slit aperture. A digital encoder using this diffraction is proposed to obtain very high resolution without a lens.

Optical rotary connector

As optical fiber usage widens, a new kind of optical fiber connector becomes necessary. This connector would be connecting two optical fiber bundles with different speeds around an axis without interruption. It is difficult to make such a connector, especially one with a hollow axis used for mechanical power transmissions. Using an optical fiber bundle for an image inversion and a differential gear system, we have developed an optical rotary connector with a hollow axis that can be used for a multichannel connection.