Basal plane sapphire is a common substrate for the heteroepitaxy of GaN. This presents a challenge for fabrication of cleaved facet GaN lasers because the natural cleavage planes in (0001) α-A12O3 are not perpendicular to the wafer surface. This paper describes a method for achieving perpendicular cleaved facets through wafer fusion that can potentially be used to fabricate GaN based in-plane lasers. We demonstrate successful fusion of GaN to InP without voids or oxide at the interface and fabricate optically flat cleaved GaN facets that are parallel to the crystallographic planes of the host InP. I-V measurements have been performed across the n-N fused interface. These results show that the fused interface exhibits a barrier for electrons passing from the InP to the GaN and ohmic conduction of electrons moving in the opposite direction.