  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.
