Data center with free-space optical communications

A data center, comprising:

• a plurality of data center units (DCUs) disposed in a region, wherein each DCU is configured to run a part or all of a data processing application, and wherein at least a first of the plurality of data center units has an optical interface unit (OIU) responsive to optical control signals;
• an internal network of one or more free space optical control and/or data communication links between nodal points associated with individual DCUs across the data center;
• and
• a network controller configured to connect or disconnect the plurality of data center units from the internal network;
• wherein the internal network comprises one or more free space optical control and/or data communication links between N nodal points (A, B, C . . .) across the region, wherein the N nodal points include one or more nodal points corresponding to individual DCUs connected to the internal network and/or one or more nodal points disposed at locations that are remote with respect to the individual DCUs, wherein the network controller comprises a router disposed at a remote nodal point A external to the plurality of DCUs, and wherein the router is configured to establish the one or more free space optical control and/or data communication links between nodal points (B, C . . . ).