Increased pump acceptance bandwidth in spontaneous parametric downconversion process using Bragg reflection waveguides.

In this paper we show that by suitably tailoring the dispersion characteristics of a Bragg reflection waveguide (BRW) mode, it is possible to achieve efficient photon pair generation over a large pump bandwidth while maintaining narrow signal bandwidth. The structure proposed consists of a high index core BRW with a periodically poled GaN core and periodically stratified cladding made up of alternate layers of Al(0.02)Ga(0.98)N and Al(0.45)Ga(0.55)N. Such photon-pair generators should find applications in realizing compact and stable sources for quantum information processing.