Tomizo Kurosawa

Bio: Tomizo Kurosawa is an academic researcher from National Institute of Advanced Industrial Science and Technology. The author has contributed to research in topics: Interferometry & Laser. The author has an hindex of 19, co-authored 82 publications receiving 1366 citations. Previous affiliations of Tomizo Kurosawa include Japanese Ministry of International Trade and Industry.

Uncertainty in pitch measurements of one-dimensional grating standards using a nanometrological atomic force microscope

Abstract: Precision measurements of 240 nm-pitch one-dimensional grating standards were carried out using an atomic force microscope (AFM) with a high-resolution three-axis laser interferometer (nanometrological AFM). Laser sources of the three-axis laser interferometer in the nanometrological AFM were calibrated with an I2-stabilized He–Ne laser at a wavelength of 633 nm. The results of the precision measurements using the nanometrological AFM have direct traceability to the length standard. The uncertainty in the pitch measurements was estimated in accordance with the Guide to the Expression of Uncertainty in Measurement. The primary source of uncertainty in the measurements was derived from interferometer nonlinearity, and its value was approximately 0.115 nm. Expanded uncertainty (k = 2) of less than 0.31 nm was obtained. It is suggested that the nanometrological AFM is a useful instrument for the nanometrological standard calibration.

Real-time, interferometrically measuring atomic force microscope for direct calibration of standards

Abstract: An atomic force microscope with a high-resolution three-axis laser interferometer for real-time correction of distorted topographic images has been constructed and investigated. With this apparatus, standard samples for a scanning probe microscope can be directly calibrated on the basis of stabilized wavelength of He–Ne lasers. The scanner includes a three-sided mirror block as a mobile target mirror for the interferometer, which realizes a rectangular coordinate system. The position coordinates of the sample is independently and simultaneously acquired with high-resolution (0.04 nm) X/Y/Z interferometer units and fed back for XY servo scanning and height image construction. The probe is placed on the sample surface at the intersection of the three optical axes of the interferometer with good reproducibility, so that the Abbe error caused by the rotation of the scanner is minimized. Image distortion in the XY plane and vertical overshoot/undershoot due to nonlinear motion of piezo devices, hysteresis, and creep are eliminated. The optical properties of the interferometers, mechanical characteristics of the scanner, and system performances in dimensional measurements for calibration standards are demonstrated.

Geometric calibration of a coordinate measuring machine using a laser tracking system

Abstract: This paper proposes a calibration method for a coordinate measuring machine (CMM) using a laser tracking system. The laser tracking system can measure three-dimensional coordinates based on the principle of trilateration with high accuracy and is easy to set up. The accuracy of length measurement of a single laser tracking interferometer (laser tracker) is about 0.3 µm over a length of 600 mm. In this study, we first measured 3D coordinates using the laser tracking system. Secondly, 21 geometric errors, namely, parametric errors of the CMM, were estimated by the comparison of the coordinates obtained by the laser tracking system and those obtained by the CMM. As a result, the estimated parametric errors agreed with those estimated by a ball plate measurement, which demonstrates the validity of the proposed calibration system.

The first measurement of a three-dimensional coordinate by use of a laser tracking interferometer system based on trilateration

Abstract: A three-dimensional coordinate of a target position was measured using a laser tracking interferometer system based on laser trilateration. Laser interferometers, which are mounted on two-directional rotating stages, track the motion of the target retroreflector. By applying the principle of trilateration, the position of the retroreflector is estimated using the optical path difference caused by the motion of the target. Four laser interferometers were used, which produced redundancy in the measurement. By taking advantage of the redundancy, the position of the interferometers and the initial position of the target is self-calibrated and consequently the target position was calculated. The measurement error of a preliminary experiment was about m for a 1 m measurement.

Whole-viewing-angle cat's-eye retroreflector as a target of laser trackers

Abstract: A spherical cat's-eye retroreflector made from a glass material having a refractive index of two was developed. The geometrical sphericity of the cat's eye and the sphericity examined optically were approximately 100 nm and 500 nm respectively. The discrepancy between these two values is discussed. This optical device is very versatile in terms of applications since it is free from viewing angle restrictions.

Digital wavefront measuring interferometer for testing optical surfaces and lenses

Abstract: A self-scanned 1024 element photodiode array and minicomputer are used to measure the phase (wavefront) in the interference pattern of an interferometer to lambda/100. The photodiode array samples intensities over a 32 x 32 matrix in the interference pattern as the length of the reference arm is varied piezoelectrically. Using these data the minicomputer synchronously detects the phase at each of the 1024 points by a Fourier series method and displays the wavefront in contour and perspective plot on a storage oscilloscope in less than 1 min (Bruning et al. Paper WE16, OSA Annual Meeting, Oct. 1972). The array of intensities is sampled and averaged many times in a random fashion so that the effects of air turbulence, vibrations, and thermal drifts are minimized. Very significant is the fact that wavefront errors in the interferometer are easily determined and may be automatically subtracted from current or subsequent wavefrots. Various programs supporting the measurement system include software for determining the aperture boundary, sum and difference of wavefronts, removal or insertion of tilt and focus errors, and routines for spatial manipulation of wavefronts. FFT programs transform wavefront data into point spread function and modulus and phase of the optical transfer function of lenses. Display programs plot these functions in contour and perspective. The system has been designed to optimize the collection of data to give higher than usual accuracy in measuring the individual elements and final performance of assembled diffraction limited optical systems, and furthermore, the short loop time of a few minutes makes the system an attractive alternative to constraints imposed by test glasses in the optical shop.

Geometric error measurement and compensation of machines : an update

Abstract: For measuring machines and machine tools, geometrical accuracy is a key performance criterion. While numerical compensation is well established for CMMs, it is increasingly used on machine tools in addition to mechanical accuracy. This paper is an update on the CIRP keynote paper by Sartori and Zhang from 1995 [Sartori S, Zhang GX (1995) Geometric error measurement and compensation of machines, Annals of the CIRP 44(2):599–609]. Since then, numerical error compensation has gained immense importance for precision machining. This paper reviews the fundamentals of numerical error compensation and the available methods for measuring the geometrical errors of a machine. It discusses the uncertainties involved in different mapping methods and their application characteristics. Furthermore, the challenges for the use of numerical compensation for manufacturing machines are specified. Based on technology and market development, this work aims at giving a perspective for the role of numerical compensation in the future.

Invited review article: high-speed flexure-guided nanopositioning: mechanical design and control issues.

Abstract: Recent interest in high-speed scanning probe microscopy for high-throughput applications including video-rate atomic force microscopy and probe-based nanofabrication has sparked attention on the development of high-bandwidth flexure-guided nanopositioning systems (nanopositioners). Such nanopositioners are designed to move samples with sub-nanometer resolution with positioning bandwidth in the kilohertz range. State-of-the-art designs incorporate uniquely designed flexure mechanisms driven by compact and stiff piezoelectric actuators. This paper surveys key advances in mechanical design and control of dynamic effects and nonlinearities, in the context of high-speed nanopositioning. Future challenges and research topics are also discussed.