DRESDEN, Germany, June 20, 2011 — Laser sources are used in the industry for labeling and materials machining applications. To meet the demands concerning precision and processing speed, optical scanner systems are applied for the modulation or deflection of light. Compared with mechanical translation stages, optical scanner systems provide benefits regarding positioning accuracy and repeatability as well as high dynamics.
Conventional galvanometer-based optical scanners feature large optical apertures. However, the macroscopic design limits the precision of motion, particularly at high velocity. Requirements for bearings of moving parts are high. A characteristic measure for the quality of motion is the dynamic mirror tilt perpendicular to the axis of rotation. Mirror tilt leads to a tumbling motion and a deformation of the projected figure.
This property often is referred to as cross-axes wobble, typically on the order of 200 µrad.
The Fraunhofer Institute for Photonic Microsystems develops custom silicon-based resonant and quasi-static microelectromechanical systems (MEMS) for deflection and modulation of light. The devices offer high velocity and precision. Scientists now have demonstrated that typical resonant designs provide a cross-axes wobble of <35 µrad. Thereby, the device oscillates at 23 kHz with a mechanical amplitude of ±9°.
For more information, visit: www.ipms.fraunhofer.de
- Any bending of a wave of radiation away from its expected path, as, for example, by diffraction or by a magnetic field.
- Electromagnetic radiation detectable by the eye, ranging in wavelength from about 400 to 750 nm. In photonic applications light can be considered to cover the nonvisible portion of the spectrum which includes the ultraviolet and the infrared.
- In general, changes in one oscillation signal caused by another, such as amplitude or frequency modulation in radio which can be done mechanically or intrinsically with another signal. In optics the term generally is used as a synonym for contrast, particularly when applied to a series of parallel lines and spaces imaged by a lens, and is quantified by the equation: Modulation = (Imax – Imin)/ (Imax + Imin) where Imax and Imin are the maximum and minimum intensity levels of the image.
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