Comparison of expressions for terahertz generation for bulk optical rectification away from normal incidence

In a paper recently published by Hargreaves, Radhanpura and Lewis (HRL), the theory of bulk optical rectification under arbitrary excitation conditions for zinc blende crystals was developed. The results from HRL have since been compared to results in the literature for (100), (110), (111), and (112) crystal faces under normal incidence of the excitation beam and good agreement found. Under these conditions, many terms in the expressions become. The purpose of the current work is to compare the expressions at non-normal incidence to gain a more general comparison between the expressions in the literature.