  Quantum affine reflection algebras are coideal subalgebras of quantum affine
algebras that lead to trigonometric reflection matrices (solutions of the
boundary Yang-Baxter equation). In this paper we use the quantum affine
reflection algebras of type d_n^(1) to determine new n-parameter families of
non-diagonal reflection matrices. These matrices describe the reflection of
vector solitons off the boundary in d_n^(1) affine Toda field theory. They can
also be used to construct new integrable vertex models and quantum spin chains
with open boundary conditions.
