This paper reviews the recently developed optical interconnect technologies designed for scalable, low latency and high-throughput communications within datacenters or high performance computers. The three typical architectures including the broadcast-and-select based Optical Shared Memory Supercomputer Interconnect System (OSMOSIS) switch, the defection routing based Data Vortex switch and the arrayed waveguide grating based Low-latency Interconnect Optical Network Switch (LIONS) switch are discussed in detail. In particular, we investigate the various loopback buffering technologies in LIONS and present a proof of principle testbed demonstration showing feasibility of LIONS architecture. Moreover, the performance of LIONS, Data Vortex and OSMOSIS with traditional state-of-the-art electrical switching network based on the Flattened-ButterFly (FBF) architecture in terms of throughput and latency are compared. The simulation based performance study shows that the latency of LIONS is almost independent of the number of input ports and does not saturate even at very high input load. This paper reviews the recently developed optical interconnect technologies designed for scalable, low latency and high-throughput communications within datacenters or high performance computers. The three typical architectures include the broadcast-and-select based Optical Shared Memory Supercomputer Interconnect System (OSMOSIS) switch, the defection routing based Data Vortex switch and the arrayed waveguide grating based Low-latency Interconnect Optical Network Switch (LIONS) switch are discussed in detail. We investigate the various loopback buffering technologies in LIONS and present a proof of principle testbed demonstration showing feasibility of LIONS architecture. Moreover, the performance of LIONS, Data Vortex and OSMOSIS with traditional state-of-the-art electrical switching network based on the Flattened-ButterFly (FBF) architecture in terms of throughput and latency are compared. The simulation based performance study shows that the latency of LIONS is alm ost independent of the number of input ports and does not saturate even at very high input load.