Fig. 1. Schematic of frequency swept principle based on multiple and high-order modulation

Fig. 2. Schematic diagram of 4 injection-locked sidebands

Fig. 3. Experimental block diagram of 4 channels broadband linearly sweeping light source

Fig. 4. Measurement of pre-compensation current signal on SL. (a) Output signal of AWG; (b) drive current signal on SL

Fig. 5. Spectral charts of single and multiple modulation signals and injection-locked signals. (a) f_RF=6 GHz; (b) f_RF=15 GHz; (c) f_RF=20 GHz; (d) injection-locked signals

Fig. 6. Optical spectrum diagram of 4 high-order modulated and frequency swept signals

Fig. 7. Optical spectrum diagram of 4 high-order injection-locked and frequency swept signals

Fig. 8. Oscilloscope time-domain signal waveforms and the 1st-order and the 3rd-order SOS sweep linearity at different ML center wavelengths. (a)-(d) when ML center wavelength is 1547, 1550, 1553, and 1556 nm, time-domain signal waveform of oscilloscope; (e)-(h) when ML center wavelength is 1547, 1550, 1553, and 1556 nm, the 1st-order and the 3rd-order SOS sweep linearity

Fig. 9. Measured frequency offset (right axis) and calculated nonlinearly error (left axis) of SOS when ML wavelength is 1550 nm