Thapar Institute of Engineering and Technology, India
Title: Dissipative soliton in VCSEL
Jana Soumendu obtained his MSc degree in 2001 from Vidyasagar University, India and PhD in 2008 from Birla Institute of Technology (BIT), Mesra, India. He worked with the CNQO group at University of Strathclyde, Glasgow, UK, during his BOYSCAST Postdoctoral Fellowship tenure. Currently, he is an Associate Professor at School of Physics and Materials Science, Thapar Institute of Engineering and Technology, Patiala, India. His research interest includes nonlinear optics, photonics and nonlinear dynamics. He published nearly fifty research papers in peer reviewed international journals and conference proceedings. He published a book entitled “Nonlinear Pulse and Beam Propagation”. He is a Referee of many internationally renowned research journals. He is also a Visvesvaraya Young Faculty Research Fellow.
Dissipative soliton (DS) are localized structure e.g., wave and pulse in lossy systems. Such DS has been excited in form of bright spot on dark background in vertical cavity surface emitting laser (VCSEL) based models in conjugation of frequency selective feedback (FSF). These DS are popularly referred as cavity soliton (CS). DS in cavity or cavity soliton (CS) exhibits intriguing dynamics, which is supported by the large area of VCSEL. The parametric space for stabilization and control of CS has been identified. The role of system randomness, an unavoidable feature that arises from multiple parameters, has been explored. Since CS dynamics is very sensitive to the any inhomogeneity present in the system we explore the possibility to use it to design an alternate microscopy, namely, ‘soliton force microscope’. However, the size of the CS is pivotal to decide the resolution of the microscope. Emphasis has given to reduce the CS spot size. Also, we searched for the systems which can be scanned with the existing size of CS. The result may lead to design a ‘soliton force microscope’ primarily with moderate resolution. A sustained CS or CS cluster requires a stable background. We found two distinct types of CS on a stable background. This may lead to realization of three-level logic. Besides, CS may be exploited to design memory devices. An essential feature of CS is the presence of their bistability character, which can be better realized by introducing a saturable absorbing material or saturable absorber (SA) in the cavity. Generally semiconductor saturable absorber mirrors are used. We explored the potential of graphene and other 2D materials as SA in VCSEL. Particularly, graphene eases the CS generation significantly as well as upgrades the CS system as an efficient biomedical sensor. The future line of investigation is highlighted.