Seminar: Brian Julsgaard

Time-resolved optical investigations of low-bandgap semiconductors

Low-bandgap semiconductors are interesting for opto-electronic applications in the infra-red region. For instance, germanium-tin alloys have been studied extensively within the past decade as a laser material in the wavelength region about 2-3 microns. This talk describes our efforts to investigate the fundamental behavior of such materials using time-resolved optical techniques. Specifically, picosecond time-resolved photoluminescence spectroscopy at wavelengths beyond 2 microns will be presented. Ongoing activities, involving transient pump-probe reflection measurements to extract additional information about material dynamics, will also be discussed.