Nonlinear dynamics of wave packets in two-dimensional parity-time-symmetric optical lattices near the phase transition point are analytically studied. A fourth-order equation is derived for the envelope of these wave packets. A pyramid diffraction pattern is demonstrated in both the linear and nonlinear regimes. Blow-up is also possible in the nonlinear regime for both focusing and defocusing nonlinearities.
© 2013 Optical Society of America
Original Manuscript: March 19, 2013
Revised Manuscript: April 19, 2013
Manuscript Accepted: April 24, 2013
Published: May 28, 2013
Sean Nixon and Jianke Yang, "Pyramid diffraction in parity-time-symmetric optical lattices," Opt. Lett. 38, 1933-1935 (2013)