TEL: 81-(0)4-7136-3385�@FAX: 81-(0)4-7136-3386
Advanced laser spectroscopy on the basis of lasers and microscopy is developed and applied to semiconductor quantum wires (QWRs) and other nano-structures, in order to understand and control their optical properties quantum mechanically which vary with their size and shape.
The structures of current interest are T-shaped GaAs quantum wires, and ridge QWRs. Their optical properties inherent to 1D systems are investigated. Combining these structures with optical waveguide structures, we have realized novel semiconductor QWR lasers and FET-type devices, for which microscopic measurements of lasing properties, emission images, and many-body effects are in progress.
Furthermore, FTIR modulation spectroscopy of intersubband transition in quantum wells, and time resolved spectroscopic characterization of new materials and structures are in progress. To improve resolution, sensitivity, and quantitative accuracy in luminescence microscopy, a new type of lens called solid-immersion lens (SIL) has been fabricated and tested. Spatial resolution better than the diffraction limit /2 by 25%, and light collection efficiency of 70% are indeed realized.