Mode switching and beam steering in photonic crystal heterostructures implemented with vertical-cavity surface-emitting lasers

Abstract

The authors demonstrate electrically controlled mode switching and beam steering in separate-contact photonic crystal heterostructures implemented with two-dimensional arrays of coupled vertical-cavity surface-emitting lasers. Two weakly coupled, lasing photonic crystal domains are switched in and out of mutual coherence by controlling the injected currents. Switching of the transverse lasing mode is accompanied by corresponding variations in the far-field pattern and the emission wavelength. Proper adjustment of the driving currents also allows steering of the beam of the ensemble of coupled lasers.

Parity-time symmetry in coherently coupled vertical cavity laser arrays

“…While the study of PT-symmetric Hamiltonians traces to the seminal paper in 1998 [19], coherently coupled semiconductor laser arrays have been studied for more than three decades [20][21][22][23][24][25][26][27][28] for applications including high brightness beam generation [29][30][31][32], beam steering [21,27,33,34], and high bandwidth modulation [35,36]. Coupled mode theory has been used to describe the supermodes of the array [23,37,38], phase velocity matching [39], and dynamics [27,40].…”

Two-Dimensional Electronic Beam Steering in Coherently-Coupled Vertical-Cavity Surface-Emitting Laser Arrays

“…In recent years, we have demonstrated electronically-controlled beam steering using vertical-cavity surface-emitting laser (VCSEL) arrays [1,2]. The electronically steerable source is advantageous since other approaches generally have discontinuous steering, incoherent fields, or complicated or unreliable mechanical parts [3][4][5][6]. However, until now, the VCSEL array laser steering has only had limited control due to unstable mode control.…”

Phase and coherence extraction from a phased vertical cavity laser array

“…In this way, it represents a closer analog to its phased array radar counterpart, affording the potential for increased efficiency with decreased power consumption and complexity. While various methods of beam steering with VCSELs have been demonstrated, typical difficulties include wide beam width, 4 out-of-phase operation, 5,6 complex mechanical parts, 7 and discontinuous steering. 1 Recently, we have demonstrated continuous electronic beam steering with full, predictable coverage up to a 1 full angle with 19%-23% efficiency in the central lobe.…”