Laser encoder features picometer resolution

Hoffman Estates, IL—RLE20 fiberoptic laser encoder system from Renishaw converts a laser interferometer from a complex scientific instrument into a simple production device that offers picometer resolution, differential measurements, and part-per-billion laser frequency stability.

By Control Engineering Staff June 6, 2006

Hoffman Estates, IL —RLE20 fiberoptic laser encoder system from Renishaw converts a laser interferometer from a complex scientific instrument into a simple production device that offers picometer resolution, differential measurements, and part-per-billion laser frequency stability. Fiberoptic capability delivers laser light directly to the measurement axes, eliminating the need for multiple remote beam splitters, benders, and adjustable mounts. The encoder is intended for X-Y positioning systems.

Fiberoptic laser encoder from Renishaw offers picometer resolution, differential measurement, and part-per-billion laser frequency stability.

The system and associated components reportedly provide sub-nanometer nonlinearity and resolution capability of 38 picometers, and are said to give precision motion system manufacturers and semiconductor equipment OEMs a fiberoptic answer to ever-tightening requirements for wafer inspection, lithography, and other yield enhancement tools. Laser unit is connected to a detector head by a 3-m fiberoptic cable. Only two components need to be aligned to form a complex axis positioning system, cutting installation time and reducing equipment footprint.

Digital output signals provide resolutions of up to 10 nm; analog signals can be used in conjunction with Renishaw’s RGE interpolators or a new RP120 parallel interface to provide resolutions of 0.39 nm and 40 picometers, respectively. The interface interpolates sinusoidal inputs by a factor of 4,096 and produces 36-bit parallel position output data. Easily integrated into bus-based architectures, each RP120 board contains a switch pack, allowing the interface to be allocated a unique address and multi-axis systems to be configured with up to seven axes.

— Control Engineering Daily News Desk Jeanine Katzel , senior editor


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