| 研究開始時の研究の概要 |
In this research, we will demonstrate all-optical modulation of a telecom wavelength optical signal at femtosecond speeds in a silicon photonic integrated device. The design, fabrication and optical verification of a nanoscale all-optical modulator will be performed.
|
| 研究実績の概要 |
In the previous year, three key objectives were achieved. First, a unique micro-pump probe spectroscopy setup was completed. The setup has the capability of injecting ultrashort laser pulses into photonic integrated circuits and measuring their time-resolved response. Using a spatial filtering system, the setup can also isolate signals output from specific elements of a photonic integrated circuit. Second, the recovery dynamics of VO2 thin films after excitation by an ultrashort laser pulse were studied. A mid-fluence region where VO2 undergoes a full insulator-metal transition while still exhibiting sub-ns recovery was discovered, thus verifying for the first time that VO2 has the potential to be modulated at GHz speeds. Finally, the photo-induced modulation of NbO2 thin films after excitation by an ultrashort laser pulse was studied and the phenomenological origins of the response was examined in detail. It was found that NbO2 has the potential to be modulated at up to THz speeds given proper management of heat dissipation. Based on this work two journal articles were compiled. One was published in December of 2019 (J. Kenji Clark et al., Phys. Rev. Res. 1, 033168 (2019)) and the other is currently under review in ACS Photonics.
|
