Transparent nanopaper for ultrashort pulse generation in the near-infrared region

Transparent nanopaper (T-paper) can be applied in the field of electromagnetic shielding materials, antistatic materials, composite conductive materials, electric pool materials, super capacitors, and thermal management systems. However, this kind of T-paper has not been employed in ultrafast photonics yet. For the first time, to our knowledge, transparent electrical nanopaper is used in fiber lasers, different from the conventional pulsed fiber laser, which operates in the Q-switched regime under low pump power and then in the mode-locked regime under high pump power. Mode-locking is achieved first with a pulse duration of 550 fs under low pump power (166 mW). When further increasing the pump power up to 198 mW, the proposed fiber laser can be converted from a mode-locked to Q-switched state, which is a result of the two-photon absorption effect. The proposed fiber laser based on T-paper can be potentially applied in optical tomography, metrology, spectroscopy, micro-machining technology, and biomedical diagnostics.