Quantum affine reflection algebras of type d_n^(1) and reflection matrices

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.