Single mode operation of a Fabry–Perot laser locked by a tunable laser

In this article, the single mode operation of a Fabry‐Perot laser (FP‐LD) subject to the optical injection from a tunable laser is investigated. The maximum side mode suppression ratio (SMSR) is 53 dB, and the locked wavelength range is about 46 nm, which can cover 58 International Telecommunication Union (ITU) wavelengths with 100 GHz spacing or 115 ITU wavelengths with 50 GHz spacing for wavelength division multiplexing (WDM) system. In the wavelength range from 1535 to 1569 nm, the SMSR is over 46 dB, and the frequency response of the injection‐locked FP‐LD can be improved with the proper wavelength detuning.