Yasuhiko Arakawa

A new type of semiconductor laser is studied, in which injected carriers in the active region are quantum mechanically confined in two or three dimensions (2D or 3D). Effects of such confinements on the lasing characteristics are analyzed. Most important, the threshold current of such laser is predicted to be far less temperature sensitive than that of conventional lasers, reflecting the reduced dimensionality of electronic state. In the case of 3D-QW laser, the temperature dependence is virtual

We discuss a number of theoretical and experimental issues in quantum well lasers with emphasis on the basic behavior of the gain, the field spectrum, and the modulation dynamics. It is revealed that the use of quantum well structures results in improvement of these properties and brings several new concepts to optical semiconductor devices.

Semiconductor quantum dots (QDs) of various material systems are being heavily researched for the development of solid state single photon emitters, which are required for optical quantum computing and related technologies such as quantum key distribution and quantum metrology. In this review article, we give a broad spectrum overview of the QD-based single photon emitters developed to date, from the telecommunication bands in the IR to the deep UV.

New semiconductor technologies such as many-core processors and 3D memories are being researched in order to overcome the limitations of electronics in the near future. Here, we first discuss some drawbacks of current technologies, and then show that silicon photonics will solve those interconnection problems. Next, we describe our studies toward realizing a system integration platform based on photonics and electronics convergence, and show that an optical interposer is the most efficient way t

We investigate theoretically a number of important issues related to the performance of AlGaAs quantum well (QW) semiconductor lasers. These include a basic derivation of the laser gain, the linewidth enhancement factor α, and the differential gain constant in single and multiple QW structures. The results reveal the existence of gain saturation with current in structures with a small number of wells. They also point to a possible two-fold increase in modulation bandwidth and a ten-fold decrease

We calculate the relaxation oscillation corner frequency fr and the linewidth enhancement factor α for both a quantum well and a quantum wire semiconductor laser. A comparison of the results to those of a conventional double heterostructure device indicates that fr can be enhanced by 2× in the quantum well case and 3× in the quantum wire case while α is reduced in both cases.

Our recent progress in GaN-based quantum dots (QDs) for optoelectronics application is discussed. First, we discussed an impact of the use of GaN-based QDs on semiconductor lasers, showing theoretically that reduction of threshold current by using the QDs in GaN-based lasers is much more effective compared to those in GaAs-based or InP-based lasers. Then discussed are our growth technology including self-assembling growth of InGaN QDs on sapphire substrates by atmospheric-pressure metalorganic c