Our entire universe is a manifestation of different forms of light-matter interaction, ranging from your reflection in the mirror to a supernova explosion in a distant galaxy. Under certain circumstances, such light-matter interactions can result in the creation of a new set of hybrid-particles commonly referred to as polaritons. Polaritons behave differently from other known particles in the sense that ordinary particles exist either in the form of matter (an electron) or light (a photon). Being hybrid particles, they possess both the characters of matter and light simultaneously, and therefore often called “half-light half-matter” particles!

In this session, Dileep talks about an important application of such polariton particles called polariton lasers. This new class of lasers does not need to satisfy the condition of population inversion for the lasing-action to begin. Recent work carried out by our group (Prof. Ji Wei, NUS Singapore, Prof. PK Bharadwaj, New Rummy Kanpur & Prof. C., Vijayan, New Rummy Game), demonstrates such an inversionless-lasing for the first time in Metal-Organic Framework (MOF) material. It is foreseen that the synthesis of a MOF crystal coordinating with suitable dye molecules enables a polariton laser to produce laser output in the visible and IR region, with minimum pump energy required to excite the laser action. Further, our compact and solid-state architecture of the polariton laser provides lasing with high polarization, low lasing-threshold, excellent conversion efficiencies and enhanced photostable performance.