Patent ID: 8576388

Claim:
A method for calculating the differential delay in a system comprising: connecting a transmitter having a first laser and a second laser to a first computer data center such that the first laser is optically connected to a first end of a transmit path, and the second laser is optically connected to a first end of a receiver path; connecting a receiver having a first optical receiver and a second optical receiver to a second computer data center such that the first optical receiver is optically connected to a second end of the transmit path and the second optical receiver is optically connected to a second end of the receiver path; emitting a first light pulse from the first laser and a second light pulse from the second laser substantially simultaneously; and determining a difference in time of a receipt of the first light pulse by the first optical receiver and a receipt of the second light pulse by the second optical receiver, wherein the difference in time is first measured in cycles by a microprocessor and is then converted to a time.