Multiple beam optical modulation system.

摘要

In a raster output scanner, a system for using one original beam and one facet of a rotating polygon to generate two consecutive scan lines. The original beam is first separated into two beams (24, 25) in a beam splitter (21). The resultant beams are polarized ninety degrees apart, and directed to an acousto-optic (A/O) modulator (22). The beams are a sufficient distance apart so that the A/O modulator can modulate each beam with a minimum of crosstalk. The output beams are then brought together to within one scan line separation by a beam recombiner (23), which is a reversed beam splitter. The beams can be brought together to this close proximity without optical interference because the beams are polarized ninety degrees apart.