Dogukan Apaydin, Avdelningen för fotonik

Sammanfattning: Photonic crystal surface-emitting lasers (PCSELs) have emerged as a promising candidate to address the limitations of current semiconductor lasers. They utilize a 2-dimensional (2D) photonic crystal that yields a 2D standing field with zero-group velocity and emission normal to the surface through diffraction. With their large gain area, PCSELs offer high single-mode output powers and circularly symmetric low-divergent emissions. PCSELs have successfully been demonstrated at different wavelengths in the electromagnetic spectrum including the visible and the infrared, still, their performance has yet to be explored in the deep-UV (λ<280 nm). The main challanges in the UV are the low refractive index of III-nitride materials, which reduces the photonic crystal effect; and the short wavelengths, which decrease the feature size and complicate the fabrication process.
We demonstrate the first deep-UV lasing from a PCSEL under pulsed optical pumping at room temperature. By engineering the photonic crystal design parameters, we show that it is possible to achieve low divergence angles despite the low refractive index of III-nitrides. Additionally, we analyze the impact of photonic crystal periodicity and lateral size on the lasing performance. Our demonstration opens a path to high-power electrically-driven UVC laser diodes.

Huvudhandledare: Åsa Haglund, Professor
Examinator: Victor Torres Company, Biträdande Professor
Biträdande handledare: Joachim Ciers, Forskningsspecialsit

Diskussionsledare: Göran Adolfsson, Dr., Coherent AB