Dr. Fumio Koyama has been one of the pioneer researchers for vertical-cavity surface emitting lasers (VCSELs), working together with Dr. Kenichi Iga, the former President and currently the Professor Emeritus of Tokyo Institute of Technology, also known as an inventor of VCSELs in 1977. The VCSEL is a semiconductor laser with ultra-small-sized, ultralow power consumption, and two-dimensional array capabilities. Dr. Koyama has been leading the world-wide VCSEL research from the beginning, realizing room temperature CW operation for the first time in 1988, and making many efforts for achieving high performance, creating new functionalities and integration with functional components. Many researchers have followed his achievements, and VCSELs are now commercialized world-wide for optical interconnection, battery-driven laser mice, lasers with small-size and low power consumption for gas sensing and face recognition systems on smart phones, and so on. He has also collaborated with industry and has been involved with the achievement of ultimate performance VCSELs such as for low threshold currents of tens of microamperes, and stable polarization control by using VCSELs grown on tilted substrates. Some of his developments have contributed to the commercialization of laser printers with high resolution by using two-dimensional arrays.
After these achievements, he has been studying high performance and the creation of new functionalities. VCSELs integrating cantilever-type micromachines is one of them, and temperature insensitive, wavelength tunable operation has been successfully realized.
He also proposed slow-light waveguide integration laterally with VCSELs, and transverse-coupled cavity VCSELs work as ultra-high-speed lasers with a modulation bandwidth of up to 20GHz and beyond thanks to external optical feedback and light injection effects. Moreover, beam steering functions have been achieved using the large angular dispersion of slow-light waveguides. The above-mentioned research are known as the field of VCSEL photonics research, and he has contributed to its development.
He has published more than 460 journal papers and has reported at more than 600 international conferences including more than 100 invited ones. He also has 8 patents.
As mentioned, he has performed leading research and developments in VCSEL photonics. From these great contributions, Dr. Fumio Koyama is awarded the Achievement Award in IEICE.
References
- F. Koyama, S. Kinoshita and K. Iga, gRoom temperature CW operation of GaAs vertical cavity surface emitting laser,h Trans. IEICE, vol. E71, no. 11, pp. 1089-1090, December 1988.
- F. Koyama, "Micromachined vertical-cavity surface emitting lasers - Athermalization, tuning, and multiwavelength integration", J. Selected Topics Qauntum Electron., vol.., vol.21, No.4, 1700310 (2015).
- H. Dalir, and F. Koyama, "40Gbps modulation of transverse coupled cavity VCSEL with push-pull modulation scheme", Appl. Phys. Express, vol.7, No.11, 092701 (2014).
- M. Nakahama, H. Gu, T. Sakaguchi, A. Matsutani, M. Ahmed, A. Bakry, and F. Koyama,"Sub-gigaherz beam switching of vertical-cavity surface-emitting laser with transverse coupled cavity", Appl. Phys. Lett., vol.107, 071105 (2015).
