Estimation of second harmonic generation efficiency of various quasi-phase matching grating structures

We have analytically calculated the efficiency factor of the second harmonic generation (SHG) in quasi-phase matching (QPM) devices of various periodic grating structures such as square, triangular, sinusoidal, trapezoidal and blazed. The phase profile representing the nonlinear optical coefficient of these grating structures has been mathematically derived and its second harmonic efficiency factors are calculated. The second harmonic conversion efficiency factors of square, triangular, sinusoidal, trapezoidal and blazed QPM structures are calculated to be 0.405, 0.164, 0.25, 0.365 and 1.0, respectively.