Abstract: An apparatus of the invention includes a non-linear optical element (NLOE) and an optical frequency discriminator (OFD). The NLOE receives an optical data signal, and introduces chirp at the leading and trailing portions of the optical pulse(s) therein or induces chirp on a continuous wave (CW) optical source coupled to the NLOE. The OFD is coupled to receive the chirped signal, and uses this signal to generate an optical clock signal. The OFD discriminates frequency content associated with chirp to enhance the optical clock signal, and may also suppress non-chirp frequency content such as may be associated with an optical carrier signal or a continuous wave (CW) signal. Related systems and methods are also disclosed.