Fig. 1. (a) TEM image of the CNTs in the dispersions. (b) The SEM image of the CNT-PVA thin film. (c) The CNT-PVA thin film transferred onto a fiber connector. (d) The transmittance of the CNT-PVA thin film.

Fig. 2. (a) Experimental setup to measure the power-dependent loss of the CNT-PVA thin film. (b) The transmission spectra of the MZI at the pump power of 0 mW (black) and 30 mW (red). (c) The change of insertion loss of the CNT-PVA thin film with the increase of pump power (control light) at 980 nm. Inset: the modulated 1550 nm output light at the 30 mW 980 nm control light (pump).

Fig. 3. (a) Simulation of the beam propagation in the heated CNT-PVA thin film. (b) The evolution of beam width.

Fig. 4. Experimental setup of an all-optical inverter with the CNT-PVA thin film.

Fig. 5. (a) Pulsed 980 nm control light (upper) and modulated 1550 nm output signal (lower). (b) A zoomed view of an output signal (black) and exponential fit (red). (c) A long-term stable output.

Fig. 6. Output signal pulses and the time constants of the front (trailing) edge when the control light (pump) with different duty cycles and (a), (c) the same peak power or (b), (d) different peak powers are applied.

Fig. 7. (a) Burst of the control light (pump). (b) The signal output.

Fig. 8. (a) Output signals with different amplitudes of the 980 nm control light at different frequencies of the 980 nm sine wave control light; (b) the corresponding peak-to-peak amplitudes.