IEEE seminar by Dr. Shilpi Gupta on "Enhanced light-matter interactions using quantum dots and photonic crystal cavities at room temperature"
#Expert
#Lecture
Control over spontaneous emission is important for many
applications in photonics, including efficient light-emitting diodes,
photovoltaics, single-photon sources and low-threshold nanolasers. Photonic
crystals can modify the spontaneous emission by creating cavities with
extremely small mode-volumes, and are an ideal platform for integrated
devices because of their scalable planar architecture. For developing
photonic devices at room temperature using such cavities, colloidally
synthesized quantum dots are excellent emitters because they exhibit high
photoluminescence efficiency and emission wavelength tunability. In this
talk, I will present our experimental and theoretical work on enhancing
light-matter interaction at room temperature, using colloidal quantum dots
and nanobeam photonic crystal cavities. Using time-resolved optical
spectroscopy, we observed enhanced spontaneous emission rate of the quantum
dots coupled to the cavity mode. We also demonstrated saturable absorption
of the quantum dots by pump-intensity dependent cavity-linewidth, which is
a nonlinear phenomenon with potential applications in optical switching at
room temperature. Using the quantum optics framework, we developed a
theoretical model to show that cavity-enhanced spontaneous emission can be
used to overcome Auger recombination (an ultrafast nonradiative process
that quenches optical gain) in colloidal quantum dots to develop
low-threshold nanolasers. In the end, I will also discuss our current
efforts towards deterministic deposition of quantum dots on photonic
crystal devices using atomic force microscopy for effective fabrication of
these devices.
Date and Time
Location
Hosts
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- Department of Electrical Engineering
- Indian Institute of Technology Kanpur
- Kanpur, Uttar Pradesh
- India 208016
- Building: ACES Building
- Room Number: DA 229
- Contact Event Host
- Co-sponsored by Yogesh Singh Chauhan
Speakers
Dr. Shilpi Gupta
Biography:
Dr. Shilpi Gupta received Ph.D. in Electrical and Computer Engineering
from University of Maryland College Park. Prior to this, she received
B.Tech. in Engineering Physics from IIT Delhi. Her broad research
interests are in studying nanoscale phenomena that have applications in
photonic, plasmonic and electronic devices. Her graduate research was
focused both theoretically and experimentally, on using enhanced
interactions between colloidal quantum dots and photonic crystal cavities
for applications in low-threshold nanolasers.
Address:Maryland, United States
Dr. Shilpi Gupta
Biography:
Address:Maryland, United States