We manipulate quantum effects by designing nanostructures and molecular structures in semiconductor materials and explore new optoelectronics beyond traditional optical phenomena and transport phenomena. We treat both inorganic semiconductors(superlattice structures etc.)and organic semiconductors(conjugated polymers etc.), with an emphasis on their functionalities for the technologically immature terahertz/infrared region, which is located between the regions of light and radio waves. These studies will lead to next-generation solid-state terahertz sources and flexible optoelectronic devices. If you join us, you will be able to perform experiments making full use of high-performance 30-femtosecond-class ultrashort equipment such as femtosecond lasers.