Event Details

Optics News

Room-Temperature Spontaneous Superradiance From Single Diamond Nanocrystals

Speaker: Ivan Cojocaru

Superradiance (SR) is a cooperative phenomenon which occurs when an ensemble of quantum emitters couples collectively to a mode of the electromagnetic field as a single, massive dipole that radiates photons at an enhanced rate. Previous studies on solid-state systems either reported SR from sizeable crystals with at least one spatial dimension much larger than the wavelength of the light and/or only close to liquid-helium temperatures. Here, we report the observation of room-temperature superradiance from single, highly luminescent diamond nanocrystals with spatial dimensions much smaller than the wavelength of light.

Main Talk

Surface Enhanced Coherent Raman Scattering Spectroscopy of Pyridine-Ethanol Mixtures and Molybdenum Disulfide (MoS2)

Speaker: Anton Shutov

Surface Enhanced Raman Scattering spectroscopy (SERS) has been extensively developed in recent 30 years. Majority of the studied systems include metal (silver, gold, aluminum) nanoparticles for enhancement of the Raman signal. However, several disadvantages of metallic substrates limit a real-world application of SERS, so many researches are focused on studying SERS with 2d materials, such as Molybdenum Disulfide (MoS2). MoS2 can be deposited as a single layer on a substrate to generate SERS signal. Alternatively, a solution containing MoS2 mono- and few- layered flakes can be combined with the molecules of interest. I will describe how one can even further improve SERS by introducing coherence in the system, i.e. by performing Coherent anti-Stokes Raman Scattering (CARS) spectroscopy. Moreover, I will show how the adding of very small amounts of MoS2 (4.4 g/cm3) to the liquid mixture of pyridine and ethanol enhances the Raman signal.