Nonlinear physical optics with transversely patterned quasi-phase-matching gratings

Transverse patterning of periodic gratings for quasi-phase-matching (QPM) at the micron scale leads to a multitude of nonlinear optical devices based on familiar physical optics effects. We demonstrate spatial control over the amplitude and phase of a second-harmonic beam in multiple slit diffraction devices and in QPM lenses, which are nonreciprocal devices.