To provide a design of a pre-scan optical element for obtaining low-cost field modularity, by replacing a considerably inexpensive optical sub-module, in the inside of the pre-scan optical element instead of the entire optical bench.

A media exposure system comprises a field-replaceable laser source sub-system which generates an exposure beam, a beam-shaping sub-system which shapes the exposure beam, and a scanning sub-system which scans the printing media with the exposure beam.