Application of Coherent Optical Techniques to Optoelectronic and Nanophotonic Materials

Coherent optical control of optoelectronic, photonic and quantum electronic materials is useful because it elicits information about fundamental physical processes. It also providing better knowledge of how these materials behave when incorporated into nanoscale and quantum devices. Here, I demonstrate quantum interference between single and two-photon absorption pathways in semiconductors. This injected and controls transient currents that are detected by terahertz emission. The results show a novel means of making unstrained and unbiased bulk silicon into an optoelectronic material, and the dependence of carrier transport on resonant excitation. Additionally, I use two-dimensional Fourier-transform spectroscopy to provide an “interaction fingerprint” in semiconductor nanostructures. The experiments isolate effects of coherent excitonic interactions in the presence of nanoscale disorder. Both two-dimensional Fourier-transform and terahertz time-domain spectroscopies are powerful tools for exploring condensed matter and nanophotonic systems. I will outline directions where these techniques are applied to interesting material systems with far reaching physics concepts or practical benefit, such as colloidal quantum dot films, semiconductor microcavities and modulation-doped quantum wells.