Design of Mirror Assembly for a DMD-Based Data Center Interconnect

Free-space data center interconnects (wireless, optical) require a reflection mechanism to avoid obstacles/interference that can arise due concentrating signals in a plane consisting of source/destination nodes. A proper reflection mechanism above the communicating nodes (as in Fig. 1) enables a beam to depart the source, hit the reflector structure well above the source and destination, and head towards the desired destination by utilizing all three spatial dimensions. This technical report involves the design of a mirror assembly (i.e. reflector structure) for 3-D beam steering in data center networks that make use of the diffraction properties of Digital Micromirror Devices (DMDs). The report is organized as follows. First, we examine the steering requirements with a flat structure that covers the the whole space between the source and destination points. Driven by the requirements of DMD, we try to complement the flat reflector surface with auxiliary mirrors. Then, we investigate the possibility of consolidating the flat ceiling reflector and the auxiliary reflectors for a unified mirror assembly design and propose an algorithm for realizing such a structure. Finally, we discuss other design options and fabrication considerations.