Satoru Tachihara

Measurement of 2D birefringence distribution

A new measuring method of 2-D birefringence distribution has been developed. It has not been an easy job to get a birefringence distribution in an optical element with conventional ellipsometry because of its lack of scanning means. Finding an analogy between the rotating analyzer method in ellipsometry and the phase-shifting method in recently developed digital interferometry, we have applied the phase-shifting algorithm to ellipsometry, and have developed a new method that makes the measurement of 2-D birefringence distribution easy and possible. The system contains few moving parts, assuring reliability, and measures a large area of a sample at one time, making the measuring time very short.

Development of a high-speed high-precision laser plotter

A high-speed, high-precision laser plotter, the Super Laser Photo Plotter (S-LPP) has been developed. S-LPP has a flat table so that both photographic plates and films can be used, and it is capable of writing fine patterns for print circuit boards (PCBs), lead frames for IC, etc., over the area of 640 mm X 819 mm with a minimum line width of 10 micrometers in 60 min. It has achieved more than fifty-times faster speed than that of a conventional plotter which has almost the same specifications as S-LPP. Several important optical techniques that have given S-LPP its own features are described.

Calculation Of White Light Optical Transfer Function (OTF) In The Existence Of Lateral Chromatic Aberration

Interpolation of lateral chromatic aberration and/or Hopkins algorithm of sinc-function are adopted to reduce the numerical error of white light OTF, where lateral chromatic aberration is present.