MXene-based high-performance all-optical modulators for actively Q-switched pulse generation

Q -switched fiber lasers are integral tools in science, industry, and medicine due to their advantages of flexibility, compactness, and reliability. All-optical strategies to generate ultrashort pulses have obtained considerable attention as they can modulate the intracavity Q factors without employing costly and complex electrically driven devices. Here, we propose a high-performance all-optical modulator for actively Q -switched pulse generation based on a microfiber knot resonator deposited with V 2 CT x MXene. Experimental results show that the obtained Q -switching pulses exhibit a wide adjustment range of repetition rate from 1 kHz to 20 kHz, a high signal-to-background contrast ratio of ∼ 55 dB , and a narrow pulse width of 8.82 μs, indicating great potentials of providing a simple and viable solution in photonic applications.