Generations of linear frequency modulation continuous

An external modulation technique for the generation of optical linearly chirped frequency continuous waves is proposed and experimentally demonstrated. The output from a distributed feedback (DFB) laser is modulated by a single sideband (SSB) modulator which is driven by a linearly chirped electrical signal generated by an arbitrary waveform generator (AWG). A high precise linear optical frequency sweep with a tuning range of 2.5GHz is successfully achieved. Due to the good modulation quality of SSB and high stability of AWG, the chirp of the electrical signal can be perfectly modulated onto the optical signal. The linearity of the optical signal is almost consistent with the linearity of the electrical signal. The best linearity of 0.9996 and the lowest jitter rate of 4.76 % are obtained from the experimental measurements which are reported in this paper.