Periodically Poled Lithium Niobate Waveguides for Quantum Frequency Conversion
This paper presents techniques for modeling annealed proton exchange (APE) and reverse proton exchange (RPE) waveguides in periodically poled lithium niobate for application to optical frequency conversion. A combination of time-dependent diffusion modeling and electromagnetic mode analysis using the RF module are used to predict the relationship between the poling period and the second harmonic generation (SHG) spectrum. Experimental SHG data are used to adjust the model, and calculated periodic poling periods are compared with measured results. Multi-mode effects are incorporated into the model and compared with experimental trends. The resulting model is successful in predicting the poling period for a given SHG process within 0.5 micron over the fundamental wavelength range from 1.5 to 2.0 microns.