  How to implement multi-qubit gates is an important problem in quantum
information processing. Based on cross phase modulation, we present an approach
to realizing a family of multi-qubit gates that deterministically operate on
single photons as the qubits. A general $n$-qubit unitary operation is a
typical example of these gates. The approach greatly relax the requirement on
the resources, such as the ancilla photons and coherent beams, as well as the
number of operations on the qubits. The improvement in this framework may
facilitate large scale quantum information processing.
