Simultaneous RGB generation in domain engineered QPM devices using type 0 DFG process

Abstract

We have theoretically demonstrated the simultaneous generation of red (R), green (G), and blue (B) wavelengths by employing the type-0 quasi-phase-matched (QPM) difference frequency generation (DFG) process in congruent LiNbO3 crystal. Various domain-engineered QPM structures are presented and analysed, aiming to achieve an excellent spectral response. The RGB emissions were observed to vary from 632 nm to 656 nm for red, 504 nm to 532 nm for green, and 449 nm to 484 nm for blue, respectively, for different configurations of input pump, operating temperature, and phase matching periods. A maximum shift of about 10 nm to 20 nm was noticed in the spectral position of the DFG peaks when the operating temperature varies from 25 °C to 60 °C. We have also investigated the effect of pump detuning and random domain fluctuations over the phase matching point on the DFG spectrum. Further, we have addressed the advantages of introducing a phase shifter (PS) domain in the periodically poled lithium niobate (PPLN) to produce excellent equal intensity RGB peaks in a single device for their potential application in a laser-based projection display system.