Nonlinear photonic structures for all-optical deflection.

We present a new type of photonic structures in quadratic nonlinear materials that enable efficient and continuous all-optical deflection. The structures are based on two-dimensional modulation of the nonlinear coefficient and consist of a set of symmetric or anti-symmetric arcs that form a periodic pattern in the propagation direction and a chirped pattern in the transverse direction. Stoichiometric lithium tantalite structures were tested by second harmonic generation. Varying the pump wavelength from 1545 nm to 1536 nm resulted in continuous angular deflection of the second harmonic wave up to approximately 2.3 degrees . Continuous deflection was also obtained by varying the crystal temperature at a fixed pump wavelength.