Program Results
2022 Annual report of Yushan scholarship Dr. Charles W. Tu
Introduction to the event
Professor Charles Tu and his partner company (Epileds Technology Inc.) are developing long-wavelength vertical-cavity surface-emitting lasers (VCSEL). According to a recent report by iLight-Counting, smart phones have already incorporated 3D sensing technology. For example, all new Apple iPhones have face ID functions, iPhone 12 Pro also has a LiDAR module. The laser source is 940-nm VCSELs. However, the issue of human eye safety is a long-term issue. Long-wavelength lasers, such as 1550 nm, are relatively safe for human eyes.
We are developing long-wavelength vertical-cavity surface-emitting laser (VCSEL) technologies by investigating light-emitting layer of dilute nitride GaInNAsSb/GaAs type-I quantum wells or strain-compensated GaAsP/InGaAs/GaAsSb type-II quantum wells grown on a GaAs/AlGaAs distribute Bragg reflector (DBR) mirror. So far, simulations of long-wavelength VCSEL structure design and growth of N-side DBR growth have been completed. The light reflectivity is more than 99% at 1550 nm.
Prof. Tu and his research team with the Riber MBE32 system at National Central University.