Interlayer engineered bilayered V₂O₅ NPs as saturable absorbers for infrared ultrashort pulse generation

Interlayer engineering offers a promising approach to modifying the structure of layered vanadium-based oxides, enhancing their saturable absorption effect and making them a desirable choice for developing infrared wavelength-range photonics devices. This experimental work synthesizes interlayer vanadium pentoxide (V2O5) using hydrothermal techniques to produce an excellent saturable absorber (SA). The interlayer engineering strategy enhances strong saturable absorption and self-defocusing effects in V2O5-based SA, enabling the generation of ultrashort pulses in the infrared region. Their superior nonlinear optical characteristics are demonstrated by a modulation depth of 13.9 % and saturation intensity of 0.42 GW cm−1, respectively. By utilizing a transmission coupling fiber-based V2O5-SA inside an Er-doped fiber laser cavity, a passively Q-switched (PQS) laser with a narrow pulse width of 2.78 μs and signal-to-noise ratio (SNR) ∼50 dB is realized for the first time. Furthermore, we explore a V2O5 NPs-SA long-term stability and high damage threshold. The results not only offer additional proof of the capable potential of interlayer V2O5 as a photo-bleaching absorber for realizing pulsed lasers in the NIR band but also cover the method for advancing their probable applications in optoelectronic devices. •In this work, interlayer vanadium pentoxide (V2O5) is synthesized using hydrothermal techniques to produce a high-quality photo-bleaching device (SA).•The saturable absorption property of V2O5 NPs-SA was measured by a balanced twin-detector system with a modulation depth of 13.9 % and a saturation optical intensity of 0.42 GW/cm2.•Furthermore, by inserting the V2O5 NPs-based saturable absorber, a passively Q-switched (PQS) laser operating at 1562.0 nm was obtained with a short pulse duration of 2.78 μs and maximum average output power of 5.6 mW.•TMO V2O5 NPs-SA provides better long-term stability with a high damage threshold and a better tolerance were examined.