Gaussian beam apodization and application in a laser printer

A novel technique for controlling the beam width of a single-mode laser beam by Gaussian apodization is discussed. Although, beam truncation is often used to compensate for the typical variations in laser diode beam divergence, such truncation imparts side lobes to the outgoing beam. Gaussian apodization or attentuation of a laser beam provides controlled beam truncation, thereby producing a clean Gaussian beam without side lobes. Typically then, the magnitude of the allowable residual beam divergence variation will be determined by the system light efficiency requirements. However, use of a Gaussian apodizer provides beam divergence control without the use of a complicated zoom system. The implementation of this concept in a prototype flying spot laser print is also discussed, with respect to the impact on the system design and other beam shaping optics, the properties of the prototype Gaussian apodizer, and the results observed during system integration.