HYBRID EVENT: You can participate in person at Rome, Italy or Virtually from your home or work.

10th Edition of World Nanotechnology Conference

March 10-12, 2025

March 10 -12, 2025 | Rome, Italy
World Nano 2022

Safayet Ahmed

Safayet Ahmed, Speaker at Nanotechnology conferences
The Hong Kong Polytechnic University, Hong Kong
Title : Two-Dimensional Gallium Sulfide as a Novel Saturable Absorber for Broadband Ultrafast Photonics Application


Two-dimensional (2D) Gallium Sulfide (GaS) offers a plethora of exceptional electrical and optical properties, allowing it to be used in a wide range of applications, including photodetectors, hydrogen generation, and nonlinear optical devices. In this presentation, the synthesis process of ultrathin 2D GaS nanosheets, using the liquid-phase exfoliation method will be discussed. Moreover, the structure, morphology, and chemical composition of as prepared nanosheets will be extensively explained. Followed by the fabrication method of 2D GaS nanosheets-based saturable absorber (SA) on a side polished fiber, will be presented for the first time. The realized modulation depths are 10% and 5.3% at 1 µm and 1.5 µm, respectively, indicating the wideband saturable absorption performance of the prepared SA. By integrating the GaS-SA into three different wavelength-based fiber laser cavities, stable mode-locked pulses are achieved, having a pulse duration of respectively. Additionally, different orders of harmonic mode-locking pulses with the highest repetition rate of 0.55 GHz (45th order) and Q-switching pulses with the shortest pulse duration of 2.2 µs are obtained in the telecommunication waveband. These findings suggest that 2D GaS has a lot of potential for broadband ultrafast photonics in nonlinear photonic devices.

Audience take-away:

  • This presentation will help the audience to learn about the saturable absorption property of 2D Gallium Sulfide (GaS).
  • Readers will get vital information regarding the characterization technique of 2D materials for photonics research.  
  • As this presentation is based on generating ultrafast pulsed laser using a novel saturable absorber, therefore, this presentation will encourage the readers to work on this topic as well. As we know ultrafast lasers are being utilized in several areas like optical communication, industrial sectors, scientific research, medical, and eye surgery, hence, this kind of research work will have a beneficial impact on society.


Safayet Ahmed is a Ph.D. candidate in the Department of Applied Physics at The Hong Kong Polytechnic University. Before starting his Ph.D., he completed his B.Sc. and M.Sc. degrees and worked as a Senior Lecturer in the Electrical and Electronics Department at American International University-Bangladesh. His research interest lies in ultrafast photonics, nonlinear optics, laser applications, perovskite solar cells, and 2D Materials characterization. His Ph.D. research goal is to characterize and optimize the properties of different kinds of novel 2D materials that can be utilized in nonlinear optics and ultrafast photonics devices. So far he has been