Kirubhashni Loganathan, Harith Ahmad, Norazriena Yusoff
This study demonstrates the synthesis of a reduced graphene oxide/cerium oxide (rGO/CeO2) composite and its successful use as a saturable absorber (SA) in ultrafast photonics. The rGO/CeO2 composite was synthesized using a facile hydrothermal approach, and an arc-shaped fiber was fabricated using a polishing technique. The arc-shaped fiber employed indirect evanescent field coupling, allowing interaction between the composite material and the laser, and facilitating the generation of mode-locked pulses. An arc-shaped fiber drop-casted with rGO/CeO2 was connected to a 2.0 μmlaser source, achieving a modulation depth of 50.16%. The emitted laser pulses have a duration of 1.428 ps, an operational wavelength of 1904 nm, and a spectral bandwidth of 2.76 nm. The pulse energy was 1.92 nJ with a high signal-to-noise ratio (SNR) of 50 dB. This study introduces rGO/CeO2 embedded in an arc-shaped fiber as an effective SA, exhibiting favorable nonlinear optical absorption in the near 2.0 μmwavelength region, making it suitable for applications in ultrafast photonics. © 2024 The Author(s).
Photonics Research Centre, Universiti Malaya, Kuala Lumpur, 50603, Malaysia; Department of Physics, Faculty of Science, Universiti Malaya, Kuala Lumpur, 50603, Malaysia; Universiti Kuala Lumpur, British Malaysian Institute (UniKL BMI), Batu 8, Jalan Sungai Pusu, Kuala Lumpur, 53100, Malaysia; Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Malang, 65145, Indonesia