Duarte and Piper introduced multiple-prism near-grazing-incidence grating cavities which originally were disclosed as copper-laser-pumped narrow-linewidth tunable laser oscillators.

[13] During the course of this research, Duarte writes that he did approach the then federal minister for energy, Sir John Carrick, to advocate for the introduction of an AVLIS facility in Australia.

[18] From the mid-1980s to early 1990s Duarte and scientists from the US Army Missile Command developed ruggedized narrow-linewidth laser oscillators tunable directly in the visible spectrum.

This research led to experimentation with polymer gain media and in 1994 Duarte reported on the first narrow-linewidth tunable solid state dye laser oscillators.

[4] These dispersive oscillator architectures were then refined to yield single-longitudinal-mode emission limited only by Heisenberg's uncertainty principle.

[23][24] Duarte's work in this area began with the demonstration of narrow-linewidth laser emission using coumarin-tetramethyl dyes[25][26] which offer high conversion efficiency and wide tunability in the green region of the electromagnetic spectrum.

[29][30][31] A further innovation in this interferometer was the use of extremely elongated Gaussian beams, width to height ratios of up to 2000:1, for sample illumination.

[35] Further developments include very large N-slit laser interferometers to generate and propagate interferometric characters for secure free-space optical communications.

[37] A spin-off of this research, with applications to the aviation industry, resulted from the discovery that N-slit laser interferometers are very sensitive detectors of clear air turbulence.

Macquarie's science reform, was widely supported by local scientists including physicists R. E. Aitchison, R. E. B. Makinson, A. W. Pryor, and J. C. Ward.

In 1980, Duarte was elected as one of the Macquarie representatives to the Australian Union of Students from where he was expelled, and then reinstated, for "running over the tables.