Thermal release tape assisted mechanical exfoliation of pristine TMD and the performance of the exfoliated TMD saturable absorbers for Q-switched laser generation

• Main Authors: Ooi, S., Ahmad, Harith
• Format: Article
• Published: Elsevier 2022
• Subjects: QC Physics
• Online Access: http://eprints.um.edu.my/42881/

This research applied an enhanced material exfoliation and transfer mechanism to process various pristine transition metal dichalcogenide (TMD) materials into a few-layer structure. The mechanical exfoliation of the TMD materials was done using a thermal release tape (TRT) with a different adhesion property compared to the scotch tape (ST) commonly used in the conventional scotch tape assisted mechanical exfoliation (ST-ME) technique. The thermal release tape assisted mechanical exfoliation (TRT-ME) performs better than the ST-ME. Four pristine TMD saturable absorbers, including molybdenum disulfide (MoS2), tungsten disulfide (WS2), molybdenum diselenide (MoSe2), and tungsten diselenide (WSe2), have been fabricated using the TRT-ME technique. Subsequently, the performances of these materials were investigated using the same experimental systems and settings. These TMD materials were tested as saturable absorbers (SAs) to induce pulsed lasing in an Erbium doped fiber laser (EDFL) cavity. The TRT-exfoliated TMD saturable absorbers were incorporated into the laser cavity by sandwiching in between two fiber ferrules using a fiber connector. Incorporating these saturable absorbers into the laser cavity has successfully induced promising Q-switching operations at the C-band region. Besides the pump power-dependent output performance, the stability and wavelength tunability of the Q-switched lasers were also studied at the maximum pump power. The findings from the studies show that the Q-switched lasers induced by the TRT-exfoliated pristine TMD saturable absorbers were stable and wavelength tunable. In the context of Q-switched laser, the TRT-exfoliated WS2 has the best performance among other pristine saturable absorbers due to its ability to generate the highest pulse energy.