A fiber optic network reduces distortion present in modulated optical signals received at an optical receiver from an optical transmitter via a fiber optic link. The optical receiver analyzes a received modulated optical signal, where the wavelength of the received signal is periodically varied at the transmitter around a center wavelength over a wavelength range. Based on the analysis, the receiver generates a link transmission curve indicative of the optical power of the received signal over the wavelength range. The network disclosed herein subsequently uses the link transmission curve to reduce the distortion caused by misalignment between the operating wavelength of a transmitter laser and a peak power wavelength at the peak power of the link transmission curve. For example, the transmitter may adjust the laser operating wavelength based on a control signal received from the receiver and generated at the receiver based on the link transmission curve.