Phase-locked laser arrays through global antenna mutual coupling

作者：Kao Tsung Yu; Reno John L; Hu Qing^*

来源：Nature Photonics, 2016, 10(8): 541-+.

DOI：10.1038/NPHOTON.2016.104

Phase locking of an array of lasers is a highly effective method in beam shaping because it increases the output power and reduces the lasing threshold. Here, we show a conceptually novel phase-locking mechanism based on 'antenna mutual coupling' in which laser elements interact through far-field radiations with definite phase relations. This allows a long-range global coupling among the array elements to achieve a robust phase locking in two-dimensional laser arrays. The scheme is ideal for lasers with a deep subwavelength confined cavity, such as nanolasers, whose divergent beam patterns could be used to achieve a strong coupling among the elements in the array. We demonstrated experimentally such a scheme based on subwavelength short-cavity surface-emitting lasers at terahertz frequencies. More than 37 laser elements that span over similar to 8 lambda(o) were phase locked to each other, and delivered up to 6.5 mW (in a pulsed operation) single-mode radiation at similar to 3 THz, with a maximum 450 mWA(-1) slope efficiency and a near-diffraction-limited beam divergence.

• 出版日期2016-8