Plasmon mediated Chiral Nanolaser

Supervisor: Dr Rahul Kumar

School: Chemistry


The importance of linearly polarized lasers in our daily life is evident from their ubiquitous presence, be it in supermarkets for barcode scanning, metal engraving/cutting shops or surgery clinics. In contrast, the circularly polarised lasers (CCL)areemerging and an active area of research. Coherent circularly polarized light has an important application in the fields like quantum information processing, quantum teleportation, remote sensing, 3D display system etc.1. However, the major drawbacks of the currently demonstrated CCL are bulky and inefficient setup-involving optical components like a quarter waveplate to convert linear polarization to circular polarization-and/or cost. For example, few CCL use organic chiral dye of high enantiopurity as a gain medium and synthesis of organic dyes with such high purity is an expensive and onerous process2. Therefore, in the proposed research, we are planning to develop a compact, economical, and efficient chiral nanolaser which generates light through the interaction of low cost, commercially available achiral dye (F8BT) and plasmonic chiral nanocavity-acting as the gain medium and resonant cavity, respectively. The meticulously designed nanocavity will support chiral lasing by creating large electromagnetic field enhancement (resonance mode) in the emission range of the achiral dye. Moreover, the proposed CCL will be designed in a way that it can be fabricated with standard semiconductor device fabrication processes. This will enable seamless integration withthe existing integrated electronic and photonic devices. Thus, creating a single integrated device that can efficiently generate circular polarised laser emission will expedite the advancements in fields where coherent circularly polarised light is crucial.The project is divided into three milestones 1) Design of high-Q chiral nanocavity 2) Fabrication of nanocavity and spin coating of thin achiral dye film 3) Characterization. This 10-week summer project will mainly focus on the first milestone where a commercial FEM simulator (COMSOL; version 6) will be used to design and optimize the geometrical parameters of the chiral nanocavity within fabrication and characterization constraints.References1) Goldstein, Dennis H.Polarized light. CRC press, 2017.2)Jiménez, Josué, et al.,"Chiral organic dyes endowed with circularly polarized laser emission."The Journal of Physical Chemistry C121.9 (2017): 5287-5292.