An item referred to as “circuitry” includes electric and/or electronic components (e.g., one or more transistors, resistors, inductors, capacitors, diodes, oscillators, multiplexers, regulators, power supplies, rectifiers, analog to digital converters, digital to analog converters, radios, antennas, logic gates (e.g., AND, NAND, OR, NOR, NEGATE, or the like), portions of an FPGA, an ASIC, or the like), or other hardware. For example, the error measurement and control circuitry 130 may include one or more transistors, resistors, inductors, capacitors, diodes, oscillators, multiplexers, regulators, power supplies, rectifiers, analog to digital converters, digital to analog converters, radios, antennas, logic gates (e.g., AND, NAND, OR, NOR, NEGATE, or the like), portions of an FPGA, an ASIC, a computer-readable medium coupled to a processor, or the like, configured to perform operations of the error measurement and control circuitry 130. Other circuitry discussed herein may be configured similarly.

The beat generator circuitry 120 may be configured to receive the optical frequency comb from the optical frequency comb generator 110. The optical frequency comb may be received by an optical circulator 121 of the beat generator circuitry 120. The optical circulator 121 may be configured to provide the optical frequency comb to a Fiber Bragg grating 122. The Fiber Bragg grating 122 may be configured to reflect a limited set of comb teeth of the optical frequency comb back into the optical circulator 121. The optical circulator 121 may be configured to provide this comb tooth set to a coupler 123. The coupler 123 may be configured to sum the single comb tooth and a frequency stabilized laser to provide a beat tone combined with the carrier envelope offset.