Lasing in quasi-periodic and aperiodic plasmon lattices
Optica , Volume 3 - Issue 7 p. 686- 693
Plasmonic particle arrays enable unconventional miniature lasers by virtue of feedback by enhanced scattering, field confinement, and diffractive resonances. Here, we demonstrate lasing in quasi-periodic and aperiodic Galois, Thue–Morse, Fibonacci, paperfolding, Rudin–Shapiro, and randomized lattice arrangements of silver particles spanning the Fourier spectrum from discrete (period-like) to increasingly continuous (random-like). Through high-NA back-focal plane images we find that the laser output displays the rich Fourier spectrum of the lattice. Conversely, the real-space output at the laser plane is similar to speckle, yet with distinctly structured autocorrelations. Further, we identify many new lasing conditions on the basis of pseudo-Bragg conditions that do not occur for periodic arrays. This work enables controlled studies of lasing for any level of spatial correlation in the feedback mechanism going from periodic to random and shows that metasurface lasers offer new beam-shaping strategies.