Hiroyoshi Funato

Lead-Lanthanum Zirconate-Titanate (PLZT) Electrooptic Variable Focal-Length Lens with Stripe Electrodes

This paper proposes new types of one and two-dimensional electrooptic (E-O) lenses of simple structure. The two-dimensional lens is composed of two one-dimensional E-O lenses which are arranged to converge light beams perpendicular to each other. The refractive index distribution of the lens is calculated using the finite-element method, and ray tracing is performed by solving the ray equation for each one-dimensional lens. Parameters of the E-O lens, such as electrode width and gap, and crystal thickness, are optimized. One and two-dimensional lenses are demonstrated, and the focusing and temporal characteristics are studied experimentally.

Holographic Scanner For Laser Printer

A holographic scanner for laser printing has been developed. The scanner includes a multiple facet disc provided with holographically produced simple linear gratings. The bow correction of a scanning line is carried out with the use of the anamorphic optics. The holographic recording material used is a surface relief phase grating which is fabricated with photoresist. The present holographic scanner allows to obtain the diffraction efficiency of up to 84% and to produce a printed copy having the resolution of 300 pixels per inch, and it has the capability of scanning 12 pages per minute with the print quality equal to that obtained by the scanner employing a polygonal mirror.

Focusing waveguide mirror with a tapered edge

We propose a focusing waveguide mirror with a shallow tapered edge in a slab waveguide and demonstrate it by planar processes and wet etching. A light beam 2 mm wide is focused to 6.5 µm full width at half-maximum at a wavelength of 0.6328 µm. A reflectivity of higher than 90% at the tapered edge is obtained. The inclination ratio of the tapered mirror edge is 1:90. Fairly good correspondence between measured and calculated focused spot sizes is obtained.

High-resolution encoder using double gratings

We propose a new signal detection method for optical encoders. Two diffraction gratings whose periods are slightly different from eachother are irradiated by a collimated beam to make an interference fringe. This encoder system has a simple structure while the performance is not influenced by the wavelength change, theoretically. A quasi sine curve of period 0.5 micrometers was detected by a fundamental experiment.

Integrated optical pickup with highly sensitive servo signal detection

We proposed a novel structure for an integrated optical pickup based on monolithic integration of waveguide mirrors and photodetectors in a waveguide on a Si substrate. The detection characteristics of focusing and tracking error signals have been demonstrated to be sufficient for practical applications.