CAPPA Students Speak at Photonics Conference 2018

March 7, 2018

SPIE Photonics West 2018

SPIE Photonics West is one of the world’s largest annual conferences for the photonics, laser and biomedical optics industries. This event consisted of three conferences and two world class exhibitions, which took place from 27th of January to 1st of February. Juan Dominguez Morales and Shumithira Gandan represented CAPPA at the conference. They were involved in presentations, meeting with collaborators, networking and attending other talks. Juan spoke about both “Silicon Photonics XIII” and “Quantum Dots and Nanostructures; Growth, Characterization, and Modeling XV”. Juan also chaired the session on “Quantum Dots and nanostructures; Growth Characterization, and Modeling XV: Session 2: Nanostructures: Growth and Analysis”. Shumithira spoke on “Carrier dynamics of Type-II GaSb/GaAs quantum rings for solar cells”.

For Juan’s first talk he spoke about, “Single-model lasing in InGaAs nanopillars on SOI” and also chaired the session. He presented the study of single model nanolaser InGaAs NPs on SOI. The laser threshold was estimated through the measurement of the emission spectra at different excitation powers. The carrier dynamics of the nanolasers was also shown with the time-resolved photoluminescence techniques. For Juan’s second talk he spoke on “Redshift of lasing modes in time-resolved spectra for GaAs-AIGaAs nanowire laser was examined with time resolved spectroscopy measurements to determine the physical characteristics of the laser modes at all low temperature intervals (4K to 60K) in the streak image. This singular phenomenon can be explained by a change in refractive index due to a decrease in carrier density with time.

Shumithira gave a presentation on “Carrier dynamics of Type-II GaSb/GaAs quantum rings for solar cells”. Type-II GaSb/GaAs quantum rings are expected to extend the wavelength of absorption in solar cells into the IR region to increase the efficiency of devices. Stacked, thin spacing layers allow more sunlight absorption per unit of solar cell volume. Here, Shumithira presented results showing that the carrier dynamics of structures with 6nm spacing layers vary greatly in contrast to similar characteristics observed between 10nm spacing layers and the reference sample. This difference is expected to be the result of miniband formation due to coupling between the quantum rings with 6nm spacing layers.

When asked about their experience at the conference Juan said “Every researcher should live the experience of giving talks at an international conference. Not only because it helps to improve your communications skills and promote your research, but also the discussion provoked after a talk increase the understanding of your own work.” Shumithira spoke about her experience at the conference stating “The discussions held when meeting with collaborators, helped progress the direction of the research I am carrying out and provided a lot of insight into other aspects that need to be taken into consideration when objective is aimed for across a few different areas of research”.