Generating multiple beams of a harmonic frequency

A system, comprising:

• an optical system comprising
• a first stage configured to receive an input of a fundamental frequency beam from a laser, to output from the optical system a first-stage harmonic frequency beam, and to output a first-stage residual fundamental frequency beam, and
• a second stage configured to receive an input of the first-stage residual fundamental frequency beam, and to output from the optical system a second-stage harmonic frequency beam, and
• one or more beam splitters configured to split one or more of the first-stage harmonic frequency beam or the second-stage harmonic frequency beam into a plurality of harmonic frequency beams;
• and
• a data writing system comprising a modulator configured to
• receive the plurality of harmonic frequency beams from the optical system in parallel and
• write parallel data to a substrate by modulating the plurality of harmonic frequency beams received from the optical system.

Enacted on an optical system comprising a first harmonic-generation stage and a second harmonic-generation stage, a method comprising:

• receiving a fundamental frequency beam from a laser;
• generating, via the first harmonic-generation stage, a first-stage harmonic frequency beam from the fundamental frequency beam;
• generating, via the second harmonic-generation stage, a second-stage harmonic frequency beam based on a first-stage residual fundamental frequency beam from the first harmonic-generation stage;
• and
• generating and outputting a plurality of output beams from the first-stage harmonic frequency beam and the second-stage harmonic frequency beam for writing parallel data to a transparent substrate.