FIG. 6 illustrates, by way of example, a block diagram of an embodiment of a machine 600 on which one or more of the methods as discussed herein can be implemented. In one or more embodiments, one or more items of the beat generator circuitry 120, error measurement and control circuitry 130, and optical frequency comb generator 110 may be implemented by the machine 600. In alternative embodiments, the machine 600 operates as a standalone device or may be connected (e.g., networked) to other machines. In one or more embodiments, one or more items of the beat generator circuitry 120, error measurement and control circuitry 130, and optical frequency comb generator 110 can include one or more of the items of the machine 600. In a networked deployment, the machine 600 may operate in the capacity of a server or a client machine in server-client network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein.