Optical interconnects have advantages of low power consumption and large bandwidth and can achieve a substantial increase in the number of nodes and switching capability for data centers. An arrayed waveguide grating router (AWGR) based architecture for high capacity optical interconnects is proposed in this paper. The tunable wavelength converter and AWGR are utilized to provide wavelength routing, and a distributed control is used to achieve fast configuration and low latency. Packet contention may occur at the buffer-less optical switches, and the optical buffering approach based on fiber delay lines (FDLs) is introduced for contention resolution. Two implementations are employed to support strictly non-blocking network and large-scale interconnection. In this paper, we analyze and compare the performance of the proposed architecture in terms of the network size, traffic mode, and buffer capacity. Simulation results indicate that the proposed architecture can interconnect 32768 nodes while providing low latency and high throughput.