As the number of processing cores that are integrated into a chip multiprocessors (CMP) continues to grow ,the traditional electric interconnection cannot meet the demands on interconnection networks .Therefore,the technology of optical interconnection is brought forward. At present, the electrical interconnection network onchip encounters a bottleneck in power, performance, bandwidth and latency, and optical interconnect is introduced into network onchip as a new way of interconnection ,which has incomparable advantages for low power dissipation,high throughput and low latency .This paper introduces the evolution of optical networks on chip,and compares the busbased architecture to torus networks and analyses the topological configuration, routing algorithms and flow control of Optical NetworkonChip(ONoC) . Finally,the prospect of the combination of the optical network onchip and 3D technology,and all optical network onchip are also discussed.