1. Probing Silicon Carbide with Phase-Modulated Femtosecond Laser Pulses: Insights into Multiphoton Photocurrent
- Author
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Ali, Ahsan, Wang, Chuanliang, Cai, Jinyang, and Karki, Khadga Jung
- Subjects
Physics - Optics ,Physics - Applied Physics - Abstract
Wide bandgap semiconductors are widely used in photonic technologies due to their advantageous features, such as large optical bandgap, low losses, and fast operational speeds. Silicon carbide is a prototypical wide bandgap semiconductor with high optical nonlinearities, large electron transport, and a high breakdown threshold. Integration of silicon carbide in nonlinear photonics requires a systematic analysis of the multiphoton contribution to the device functionality. Here, multiphoton photocurrent in a silicon carbide photodetector is investigated using phase-modulated femtosecond pulses. Multiphoton absorption is quantified using a 1030 nm phase-modulated pulsed laser. Our measurements show that although the bandgap is less than the energy of three photons, only four-photon absorption has a significant contribution to the photocurrent. We interpret the four-photon absorption as a direct transition from the valance to the conduction band at the {\Gamma} point. More importantly, silicon carbide withstands higher excitation intensities compared to other wide bandgap semiconductors making it an ideal system for high-power nonlinear applications., Comment: 14 pages, 4 figures
- Published
- 2023