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DOE OSTI · 1246887

Phase-locked laser array through global antenna mutual coupling

Kao, Tsung -Yu·Reno, John L.·Hu, Qing
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Abstract

Here, phase locking of an array of lasers is a highly effective way in beam shaping, to increase the output power, and to reduce lasing threshold. In this work, we present a novel phase-locking mechanism based on "antenna mutual coupling" wherein laser elements interact through far-field radiations with definite phase relations. This allows long-range global coupling among array elements to achieve robust 2-dimensional phase-locked laser array. The new scheme is ideal for lasers with deep sub-wavelength confined cavity such as nanolasers, where the divergent beam pattern could be used to form strong coupling among elements in the array. We experimentally demonstrated such a scheme using sub-wavelength short-cavity surface-emitting lasers at terahertz frequency. More than 37 laser elements are phase-locked to each other, delivering up to 6.5 mW single-mode radiations at ~3 terahertz, with maximum 450-mW/A slope efficiency and near diffraction limit beam divergence.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS

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Kao, Tsung -Yu, Reno, John L., Hu, Qing. 2016-01-01. Phase-locked laser array through global antenna mutual coupling. https://doi.org/10.1038/nphoton.2016.104

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