Due to the high burstiness and high-bandwidth characteristics of the services, optical interconnect in intra-datacenter networks has attracted much attention. Many datacenter applications in the environment require lower delay and higher availability with the end-to-end guaranteed quality of service. In this paper, we propose a novel latency-aware software defined networking (LaSDN) architecture for OpenFlow-based optical interconnect in intra-datacenter networks, by introducing a latency-aware service scheduling (LaSS) strategy. LaSDN can arrange and accommodate the applications with required QoS considering the latency factor, and enhance the responsiveness to quickly provision for intra-datacenter demand. The overall feasibility and efficiency of the proposed architecture are experimentally verified on our testbed with real OpenFlow-enabled tunable optical modules.