All-integrated mid-infrared laser sources
Gayathri Bharathan — Jak Kelly Award Winner (2019)
Department of Physics and Astronomy
Macquarie University
Date: Wednesday, 4 December 2019, 6.00pm for 6.30pm
Venue: Gallery Room, State Library of NSW (Entrance: Shakespeare Place, Sydney)
The infrared (IR) part of the electromagnetic spectrum is sub-divided into the near (0.8 – 2 μm), mid (2 - 15 μm) and far (15 - 1000 μm) infrared region. Amongst those three, the mid-IR is of particular relevance as it corresponds to photon energies that overlap with the strong vibrational molecular resonances of most common constituents of atmospheric gases and with the liquid water. Potential applications include but are not limited to environmental monitoring, trace molecular detection (e.g. for airport security screening) as well as non-invasive breath analysis where the presence of certain molecules in the human breath can be used as an indicator of a specific disease.
Due to their numerous advantages, fibre lasers represent the ideal light sources for most applications and have therefore become the most widespread used type of lasers in the near-IR. In contrast, mid-IR fibre laser technology is still in its infancy, mainly due the nonexistence of fibre coupled optical components required to form an all-fibre cavity, which severely limits their applicability. The possibility to utilize femtosecond lasers to directly inscribe high-quality and robust integrated components such as fibre Bragg gratings as well as in-fibre polarizers opens a new avenue for the development of future mid-IR all-fibre laser systems. The aim of my research work is therefore to investigate the fabrication of integrated components in mid-IR compatible glasses for the development of high beam quality all-fibre mid-IR lasers.
Gayathri Bharathan completed her Bachelor’s degree in Electronics and Communication Engineering at Mahatma Gandhi University in Kerala, India. This was followed by post-graduate studies in VLSI Design from Indian Institute of Technology, Madras (IIT Madras). Later, she worked as a lecturer in the Federal Institute of Science and Technology for two years. She then returned to her studies in 2017, relocating to Sydney to pursue a Masters by Research in Photonics at Macquarie University. Her interest in the field of developing lasers for surgical applications led her to continue her studies and she commenced a PhD in March 2018 under the supervision of Dr Alex Fuerbach and Dr Stuart Jackson. At the completion of her PhD, she hopes that she can continue to contribute to the development of new mid-infrared laser sources for practical applications in medicine.