Optical materials 

Organic semiconductors enable the development of “flexible” optical detectors and light sources due to their physical features. Such devices are thin, light, and bendable and can be formed on flexible substrates such as plastic or ultra-thin glass films. Moreover, they can simply be formed by using ordinary processing techniques such as printing or evaporation. We believe that organic semiconductors could provide a novel platform for optical technology and be utilized over a wide range of applications.

Quantum cascade lasers (QCLs) are promising light sources in the mid-infrared (IR) and terahertz (THz) spectral ranges (3 μm to 300 μm). In particular, the 1 THz to 6 THz spectral range is very attractive for many applications, such as imaging, chem-/bio-sensing, heterodyne detection, and spectroscopy. However, there is a lack of high-performance compact light sources that can operate in this spectral range still at room temperature. QCLs based on the anti-crossed dual-upper-state (AnticrossDAUTM) active region, which was originally developed by our group, are a promising candidate due to its broad bandwidth as well as its high performance in devices. Recently, we developed room-temperature electrically-pumped THz QCL sources on the basis of the DAU active region that successfully demonstrated the highest THz output power with a high mid-IR-to-THz conversion efficiency of >1 mW/W2. We have also demonstrated the first terahertz-range imaging at room temperature using our THz QCL*.


*The room temperature THz-QCL is currently under development.

iPMSELs are surface-emitting-lasers originally developed by us that emit an arbitrary two-dimensional beam pattern directly from needle-tip-sized devices. In addition, the beam patterns can easily be switched electrically by integrating several devices into a module. The potential applications include LiDAR, three-dimensional shape measurement, indication, with our ultimate goal to realize a key light source for true three-dimensional displays.