Christoph Weichert, Jens Flügge, Paul Köchert, Rainer Köning, Rainer Tutsch
A heterodyne interferometer with spatially separated input beams is presented. The optical design realizes symmetric paths through glass and air, which results in a minimal dead path. An automatic correction of phase variations introduced by feeding the optics with fibers and by angle variations between the optics and the mirror is demonstrated. In addition to the resolution and linearity in the single digit picometer range, the long-term stability of the interferometer setup is investigated, involving the previous analysis of all different components of the setup. It is shown, that the...
TC14 LMPMI Symposium 2011
· TC14
· 2011
· Download
Arjan J. H. Meskers, Jo W. Spronck, Robert H. Munnig Schmidt, Jonathan D. Ellis
Heterodyne interferometry is a widely applied technique for length and displacement measurements in precision systems. Free-space optical beam delivery couples the source directly to the interferometer location. Conversely, fiber delivery is desired to decouple the source and interferometer. Drawbacks to using fibers are either time consuming alignment (PM fiber) or time varying polarization output (MM fiber). Jones matrices were used to analyze Joo-type interferometers to simulate the effects of using MM fiber inputs. The results showed loss of interference at some instances from the...
TC14 LMPMI Symposium 2011
· TC14
· 2011
· Download
T. Wakayama, T. Yoshizawa
Inner profile measurement is an important matter in such fields as mechanical engineering including car and aircraft industries, and heavy industry relating to jet engines and power plant. In addition, we can find many applications in medicine and/or surgery related field. Here we describe recent development of our measurement principle for inner diameter and profile of pipes and/or tubes. The key device in this technique is a ring beam device which consists of a conical mirror and a laser diode (LD). And the fundamental principle is based on optical sectioning without using any contact...
TC14 LMPMI Symposium 2011
· TC14
· 2011
· Download
Albert Weckenmann, Johannes Bernstein
At the Chair Quality Management and Manufacturing Metrology (QFM) a prototypic optical measurement method for in-line measuring of extruding with 800°C and movement speeds up to 10 m/s has been investigated and evaluated in the shop successfully. The method combines multiple light-section systems and a shadow system for measuring concave extruding more accurate than before. The measurement uncertainties operate down to 10 µm in measurement ranges of 100 mm. The already evaluated method can fundamentally be used as well for measuring other objects, e.g. with high aspect ratios. The here...
TC14 LMPMI Symposium 2011
· TC14
· 2011
· Download
B. Bodermann, S. Bonifer, E. Buhr, A. Diener, M. Wurm
At PTB different laser scatterometers with partly novel and outstanding metrological capabilities have been developed and are available for high-resolution dimensional metrology of periodic nanostructures. Two different systems are described and their metrological potential discussed: a laser diffractometer for pitch calibration and a versatile goniometric scatterometer for multi-parameter characterisation of nanostructures.
TC14 LMPMI Symposium 2011
· TC14
· 2011
· Download
A.V. Latyshev
The number of methodological recommendations has been pronounced to describe correctly low-dimensional structures up to atomic resolution and to fabricate crystalline surfaces for applicability in nanoscale metrology. Technology of an extremely flat mirror for optical and laser metrology has been demonstrated on the base of crystalline surface. Stepped crystalline surface with controlled steps distribution is a precise calibrator at nanoscale measurements which is suitable for high-resolution techniques. The precision of measurements performed by atomic-force microscopy (AFM) and...
TC14 LMPMI Symposium 2011
· TC14
· 2011
· Download
Wolfram Lyda, Avinash Burla, Marc Gronle, Wolfgang Osten, Jan Zimmermann, Oliver Sawodny
Inspection systems with multiple sensor systems offer the opportunity to select the most suitable sensor according to the measurement task. A challenging objective consists of an automatic selection of the relevant sensors and their embedding into an effective measurement chain. In this publication, we present the implementation of an automated multiscale inspection strategy into a system for the inspection of MEMS and micro lens arrays and give an extended outlook on future challenges which have to be solved to adapt such a system to inspect complex technical components.
TC14 LMPMI Symposium 2011
· TC14
· 2011
· Download
Toshitaka Wakayama, Toru Yoshizawa
To improve difficulties inherent to the conventional three-dimensional profiling system based on pattern projection method, we have proposed incorporating a recent digital device such as a MEMS scanner into projection optics. We have used the MEMS scanner which is not a digital mirror device (DMD) but a single MEMS mirror.Due to this revision, first of all, such a small size system like a palm-top camera was attainable, and low cost measurement system was potentially realized. In the projection system, a laser diode and the single MEMS mirror are employed. We can control the scanner to...
TC14 LMPMI Symposium 2011
· TC14
· 2011
· Download
Fumio Kobayashi, Yukitoshi Otani, Toru Yoshizawa
A projection moiré profilometry using a pair of liquid crystal digital gratings (LCDG) is applied to determine a step height using two liquid crystal digital gratings (LCDGs). Moiré contours are filtered over to remove the images of the original grating from the moiré counter when a pairs of grating images are traveled to the same direction in-phase electrically. The new idea of this report is proposed to overcome the 2 π ambiguity of moiré contour by changing the fringe interval of Moiré contours which are adjusted the period of LCDGs. The measured accuracy has been achieved to ±0.7 mm in...
TC14 LMPMI Symposium 2011
· TC14
· 2011
· Download
B. Ribbens, S. Vanlanduit, J. J. J. Dirckx, P. Cools
Profilometry with LCD or DLP beamers has become a common three-dimensional scanning technique. Many attempts are made to enhance the accuracy of these measurement systems, by developing new algorithms or improving the existing ones. Comparing these algorithms to the existing methods requires building a validation setup. This validation setup has to be carefully calibrated to obtain realistic measurement data. Additionally the distortions of the different components need to be compensated. Building these setups often takes a lot of valuable research time while the goal of many research...
TC14 LMPMI Symposium 2011
· TC14
· 2011
· Download