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Precision of light

PTB colloquium on measurement and sensor technology based on laser interferometry


[ptb]As a handyman one is usually very well served with measuring tape and slide gauge. However, if a length is to be precisely measured for industrial purposes, more exact measures are a must. Light is especially well suited for this purpose, as an extremely fine subdivision is possible: about 100 wavelengths fit in the diameter of a human hair. And as light radiation can moreover be very well reproduced, interferential length measurement methods using visible (laser) light are today applied in many technical fields. Professor Dr. Gerd Jäger presents the potentialities and limits of these methods in a colloquium to be held in the lecture hall of the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig on February 9, 2001. All those interested are invited to attend.

Professor Jäger, who heads the department of process measuring technology of Ilmenau Technical University, will first give a survey of the different methods used in interferometry-based measurement and sensor technology ­ including their advantages and disadvantages. He will then explain the efficiency of these methods by some examples which will show the different dimensions of the fields of use: from nanometrology to force measuring and weighing techniques. The importance of highly precise length measuring techniques for other fields of metrology will be emphasized.

The colloquium is held to celebrate the 60th birthday of Dr. Manfred Kochsiek, the PTB's Vice-president. Since Professor Kochsiek joined PTB in 1966, he has rendered outstanding services in the field of metrology. He was head of the "Unit of Mass" and "Mechanical Weighing Instruments" sections, then rose to the positions of head of department and head of division, and finally, in 1993, joined the PTB's Presidential Board. He is now above all concerned with management tasks, but his attention continues to be directed to the constant further development of metrology. This is reflected in numerous publications and by his work as an expert and as a member of scientific advisory committees.