A system and method for generating an optical return-to-zero signal with frequency chirp. The system includes a bit separator configured to receive an electrical non-return-to-zero signal and generate a first input signal and a second input signal. Additionally, the system includes a first driver configured to receive the first input signal and generate a first driving signal. The first driving signal is proportional to the first input signal in signal strength. Moreover, the system includes a second driver configured to receive the second input signal and generate a second driving signal. The second driving signal is proportional to the second input signal in signal strength. Also, the system includes a light source configured to generate a light, and an electro-optical modulator.