The traditional approach for inter-domain Traffic Engineering Label Switching Path (TE-LSP) computation like BRPC
could provide a shortest inter-domain constrained TE-LSP, but under wavelength continuity constraint, it couldn't
guarantee the success of the resources reservation for the shortest path. In this paper, a Collision-aware Backward
Recursive PCE-based Computation Algorithm (CA-BRPC) in multi-domain optical networks under wavelength
continuity constraint is proposed, which is implemented based on Hierarchical PCE (H-PCE) architecture, could provide
an optimal inter-domain TE-LSP and avoid resources reservation conflict. Numeric results show that the CA-BRPC
could reduce the blocking probability of entire network.