Abstract: An integrated circuit that includes a wavelength meter is described. This integrated circuit may include: a set of interferometers having integer multiples of a phase or a delay, where the set of interferometers provide outputs corresponding to a range from an MSB to an LSB of a wavelength in an optical signal. For example, the set of interferometers may include MZIs or ring resonators. Moreover, the integrated circuit may include a converter that provides digital electrical signals that specify the range from the MSB to the LSB. Note that the set of interferometers may have different FSRs, where an interferometer that provides an output corresponding to the MSB has a largest FSR and a smallest phase or delay, and a second interferometer that provides a second output corresponding to the LSB has a smallest FSR and a largest phase or delay.