Tag Tianshu Lai

Entries 2 Total

Bulk Vortex and Horseshoe Surface Modes in Parity-Time Symmetric Media

Mar 20, ’14 7:20 AM

Huagang Li, Xing Zhu, Zhiwei Shi, Boris A. Malomed, Tianshu Lai, Chaohong Lee

We demonstrate that in-bulk vortex localized modes, and their surface half-vortex (“horseshoe”) counterparts (which were not reported before in truncated settings) self-trap in two-dimensional (2D) nonlinear optical systems with PT-symmetric photonic lattices (PLs). The respective stability regions are identified in the underlying parameter space. The in-bulk states are related to truncated nonlinear Bloch waves in gaps of the PL-induced spectrum. The basic vortex and horseshoe modes are built, severally, of four and three beams with appropriate phase shifts between them. Their stable complex counterparts, built of up to 12 beams, are reported too.

http://arxiv.org/abs/1403.4745
Optics (physics.optics); Pattern Formation and Solitons (nlin.PS)

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Surface solitons in PT-symmetric potentials

Apr 27, ’13 9:32 PM

Huagang Li, Zhiwei Shi, Xiujuan jiang, Xing Zhu, Tianshu Lai

We investigate light beam propagation along the interface between linear and nonlinear media with parity-time PT symmetry, and derive an equation governing the beam propagation. A novel class of two-dimensional PT surface solitons are found analytically and numerically, and checked to be stable over a wide range of PT potential structures and parameters. These surface solitons do not require a power threshold. The transverse power flow across beam is examined within the solitons and found to be caused by the nontrivial phase structure of the solitons. PT surface solitons are possibly observed experimentally in photorefractive crystals.

http://arxiv.org/abs/1304.6788
Optics (physics.optics); Pattern Formation and Solitons (nlin.PS)

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