Spatial Light Modulators
Fraunhofer Institute for Photonic Microsystems
- One-Dimensional Spatial Light Modulators on Wafer.
The spatial light modulators developed at Fraunhofer IPMS consist of arrays of micromirrors on semiconductor chips, whereby the number of mirrors varies depending on the application, from a few hundred to several millions. In most cases this demands a highly integrated application specific electronic circuit (ASIC) as basis for the component architecture in order to enable an individual analog deflection of each micromirror. In addition, Fraunhofer IPMS develops electronics and software for mirror array control.
The individual mirrors that vary in number and size per chip depending on the application can be tilted or vertically deflected depending on the application, so that a surface pattern is created, for example to project defined structures. High resolution tilting mirror arrays with up to 2.2 million individual mirrors are used by our customers as highly dynamic programmable masks for optical micro-lithography in the ultraviolet spectral range. The mirror dimensions are 10 μm or larger. By tilting the micromirrors, structural information is transferred to a high resolution photo resist at high frame rates. Further fields of application are semiconductor inspection and measurement technology, microscopy and prospectively laser printing, marking and material processing.
Piston micromirror arrays based on 240 × 200 individual mirrors (40 × 40 μm²) can for example be used for wavefront control in adaptive optical systems. These systems can correct wavefront disturbances in broad spectrum ranges and thereby improve image quality. The component capabilities attract special interest in the fields of ophthalmology, astronomy and microscopy, as well as in spatial and temporal laser beam and pulse shaping.