Analysis of a phase reversal quasi-phase matching device for the dual peak second harmonic response

Abstract

Phase reversal quasi-phase matching devices are fairly capable of yielding a dual peak second harmonic spectral response. However, it does suffer from uneven intensity and overlapping of the peaks. In this paper, we analyze the effect of the errors to which these devices are prone. Such unavoidable errors are bound to happen during the poling process even under controlled conditions. The second harmonic spectral response is analyzed by introducing two sorts of possible errors in an ideal phase reversal quasi-phase matching device. Initially, the aperiodic domain is kept fixed at the center of the device and its width is altered to determine the intensity variation of the peaks. When the width of the aperiodic domain is not equal to twice the periodic domain width, an unequal peak response is observed. Secondly, the aperiodic domain width is kept constant while the aperiodic domain is moved along the length of the device to determine the interference between the peaks. If the aperiodic domain is not positioned exactly at the center, a disturbance of the peaks’ intensities is noticed.

A systematic approach for designing quasi-periodic optical superlattices using the Hadamard matrix

“…The second structure we consider is a periodic QPM device except that it has a phase-reversal domain in the middle of the crystal with a width of (twice the domain width) [24,32] and it is represented by the column number (N/2) + 1 of the Hadamard matrix. Its corresponding power spectrum, f 513 (ν), SHG tuning curve and QPM grating structure are rendered in figure 2.…”

Effect of Phase-Shifter Domains in Quasi-Phase Matching Devices

“…57.1b-d. With the presence of PS domains, the phase of the second harmonics is reversed by π giving two peaks near the phase matching point [5][6][7][8][9]. We introduced one, three and five numbers of PS domains in the periodic grating structure and theoretically analyzed the dependence of PS domains to the intensity of SH dual peaks and separation between the peaks.…”