GalvoSpiegel

GalvoSpiegel is a term used in optics to denote a galvanometer-based scanning mirror assembly that steers a light beam. The name combines the German Galvo (galvanometer) and Spiegel (mirror), reflecting its two-axis rotating mirror mechanism used to direct laser or light beams in imaging, projection, and processing systems.

Construction typically includes one or two fast-swing galvanometer motors connected to near-weightless, highly polished mirrors mounted on precision bearings. The assembly is integrated with high-voltage or current-controlled drivers and a feedback sensor, such as an optical encoder or Hall-effect sensor, enabling closed-loop control. The system converts electrical commands into angular deflection, allowing patterns like raster scans, vector drawing, or custom trajectories.

Key performance metrics include angular range, resonant frequency, angular resolution, linearity, drift, and settling time. Closed-loop designs improve accuracy and repeatability, but inertia and mechanical limits cap maximum scan speed and amplitude. Optical coatings and mirror size influence reflectivity and heat management.

GalvoSpiegel assemblies are widely used in laser scanning microscopy, holography, laser projection systems, laser marking and engraving, spectroscopy, and microfabrication. They offer fast, non-contact beam steering with high angular precision but require careful calibration, thermal management, and periodic alignment to maintain performance. Wear and bearing friction can affect long-term stability; compensation for nonlinearity and optical distortion is common.

Origin traces to galvanometer-based scanning used in early instrumentation; modern GalvoSpiegel units emerged in the late 20th century as compact, high-precision beam steering components. See also galvanometer mirror, laser scanning, and optical projection systems.