Supersymmetry Laser Arrays with High-Order Exceptional Point

Supersymmetry (SUSY) laser array with superpartner structure can suppress excess modes to achieve high-intensity and high-coherent radiation. Compared with complex superpartner, using parity time (PT) symmetry broken to manipulate SUSY laser arrays is a more flexible approach. Herein, based on ultrathin perovskite single crystal, a SUSY laser array is constructed without superpartner, but with auxiliary gain-loss structure. PT symmetry broken with high-order exceptional point (EP) is realized in the visible spectral range. It intrinsically avoids superpartner field mismatch and improves side mode suppression ratio 8.8-12 dB for single-mode lasing. Furthermore, variations in EP-order enable the transition from single-mode to dual-mode or tri-mode radiation and retain amplified radiation characteristics. In addition, these SUSY laser arrays with the high-order EP have the potential to be small-volume optical sensor devices. The new design combining SUSY and PT symmetry broken presents its potential in micro-nanophotonic devices with the benefit of small size, flexibility in spectral control, expandability, simplicity, and multifunctionality feature.