Center Director: Fumihiko Kaminari (Professor, Faculty of Science and Technology)
Primary Campus: Yagami
Center Overview
Under the MEXT budget, Keio University forms a collaborative research hub as part of the Advanced Photon Science Alliance (Advanced Lightwave Control and Application Technology) with the University of Tokyo, RIKEN, the University of Electro-Communications, and the Tokyo Institute of Technology. The center is primarily responsible for (i) promoting cooperative R&D and utilization research of photon ring facilities and (ii) projects in materials science for the realization of high-intensity lasers. In addition, it conducts research in conjunction with the promotion of ongoing research themes since the start of this research project.
Specific topics include:
Development of ultra-broadband vector-shaped laser pulses for the formation of spatiotemporally controlled plasmonic reaction fields
Elucidation of nanoscale crystal structure dynamics and its application to nano-imaging measurements
Fusion research of frequency comb light sources and lightwave control technology
Blue diode-pumped Pr:ZBLAN fiber laser and its mode-locked oscillation
Development of femtosecond lightwave control technology
Development of a mode-locked light source using four-wave mixing in a toroidal optical resonator
Development of precision polarization measurement of terahertz electromagnetic waves and its application technology
Fabrication of nitrogen-vacancy centers in diamond and their application to nano-light sources and nano-sensors.
Keywords and Main Research Themes
Ultrafast Optical Science Laser Engineering Near-field Optics Nano-reaction Field Science
FY2017 Business Plan
■ Activities Continuing from the Previous Fiscal Year: Background, Rationale, and Goals
The project budget from MEXT is expected to be granted for FY2017, and we will continue to advance research on themes 01 to 08 from FY2016, aiming to develop new light source technologies and their applications. All of these themes are being pursued with the goal of completion by the end of FY2017.
Furthermore, we will continue to host seminars and symposiums to disseminate optical science and technology and foster human resources.
■ New Activity Goals, Content, and Background for FY2017
This marks the 10th year of continuing research since the center was established with funding from MEXT. In response to the new research goals set for the collaborative hub since 2012, as listed below, we will review our research content to align with these goals and concentrate our research resources, particularly on light source development.
Developing fundamental technologies for the realization and dissemination of international frequency standards through complete frequency control
Development and utilization of coherent light sources from X-ray to terahertz regions through complete control of ultrashort light pulses
Generation and utilization of ultra-high-intensity light through complete control of broadband optical amplification
In line with this research content, the following themes will be implemented in the final fiscal year.
Formation of spatial correlations in local computing/memory elements using phase-change materials and the emergence of computing functions
New broadband and narrow-linewidth infrared spectroscopy
Development of energy-saving optical frequency comb light sources using micro-optical resonators
Fusion of photonic crystal engineering with silicon photonics
Generation of large-scale cluster states by controlling inter-mode quantum correlations of a frequency comb
Imaging of non-repetitive phenomena using the ultrafast burst imaging method
Development of visible-range double-clad fiber lasers and oxide laser media for the visible range
Development of precision polarization measurement of terahertz electromagnetic waves and its application technology
Fabrication of nitrogen-vacancy centers in diamond and their application to nano-light sources and nano-sensors
In addition to the budget for hub formation, we are advancing discussions to cultivate the results of our lightwave control research into innovative deep-ultraviolet laser technology, to expand nanophotonics research into the complex system physics of materials, and to establish research for optically realizing quantum simulators. We will engage in activities to acquire funding as needed.
FY2017 Business Report
■ Implementation Details, Research Results, and Degree of Achievement against the Business Plan for the Fiscal Year
We successfully focused and propagated femtosecond plasmon pulses with wavelengths of 400 nm and 800 nm onto the tip of an aluminum tapered chip with a diameter of approximately 35 nm. Using Raman-resonant four-wave mixing, we succeeded in vibrational mode-selective coherent anti-Stokes Raman scattering imaging of graphene and carbon nanotubes. Furthermore, we fabricated nanographene by reducing graphene oxide using this plasmon focusing method.
We experimentally confirmed the change in the optical spectrum (spectrum of resonant modes) corresponding to the matching between the 2D pattern written on a phase-change material and the electric field distribution of the cavity mode, thereby demonstrating the coding of 2D information into a 1D spectrum.
We performed sub-Doppler resolution spectroscopy of phosphine molecules using a mid-infrared difference frequency generation source controlled by a frequency comb.
By increasing the blue diode laser pump power to 20 W, we investigated the scalability of the visible laser output and the effects of thermal load. Since the use of Pr3+, Mg2+:SrAl12O19 and Pr3+:YAP, Pr3+:YAG, which have excellent thermal properties, is essential for future use of higher-power blue diode lasers for pumping, we fabricated ceramics, which is unprecedented for visible lasers. We confirmed that the former two materials could be oriented and sintered by applying a magnetic field to the slurry state before sintering. We grew the materials and measured their emission characteristics. We also developed a strong magnetic field application device for fabricating these biaxial crystals as ceramic materials. Additionally, we investigated the properties of Co:MALO crystals, which can be used as a saturable absorber for passive Q-switching even at green wavelengths, and achieved passive Q-switching and intracavity SHG in the green for the first time.
We introduced an optical system capable of extending the 25-frame ultrafast imaging measurement per pulse to a sub-nanosecond time window and confirmed the generation of a laser ablation plume in a single shot. We also constructed a THz generation device and developed an experimental system capable of measuring a hyperspectral image of THz waves with a single pulse.
By appropriately designing the structural dispersion of a micro-optical resonator, we achieved anomalous dispersion and obtained mode-locked, ultrafast repetitive pulse light. Furthermore, while coupling microresonators causes mode splitting of the resonant wavelength, we realized a Brillouin laser by precisely controlling the mode-split width to match the frequency of the Brillouin gain.
We expanded the development of internal strain inspection technology for rubber materials using terahertz polarization measurement, enabling 2D imaging inspection.
Aiming to realize high-performance nano-light sources and nano-sensors using nitrogen-vacancy centers in diamond, we proceeded with optimizing the conditions for substrate microfabrication and nitrogen-doped chemical vapor deposition that we have been conducting, and made improvements to further increase the brightness and sensitivity of the nitrogen-vacancy centers.
■ Number of Published Papers (with names of major journals), Number of Conference Presentations (Domestic and International), and Achievements in Social Contribution such as Events (Date, Location)
Number of published papers: 31 (e.g., Appl. Phys. Express, Applied Physics Letters, Optics Express, Applied Optics, Sci. Report)
Number of conference presentations (64 domestic, 92 international)
Center-hosted seminars and symposiums (1): The 38th Advanced Photon Science Alliance Seminar, "New Optical Science through Lightwave Control: A Challenge by Keio University," March 2, 2018, Raiosha, Keio University.
■ Special Achievements through Center Activities
This center serves as the organizational body for Keio University's participation as a collaborative hub in MEXT's Optical Hub Formation Project. It has contributed not only by promoting research projects through collaborative research among its members but also by advancing initiatives to disseminate optical science and technology by hosting symposiums. Furthermore, we collaborated on applications to secure funding for the next term, which led to our selection for a FY2017 JST CREST research project (5 years). We are also proceeding with considerations to apply in collaboration with the University of Tokyo for the MEXT Q-LEAP program starting in FY2018.
Project Members
Principal Investigator
Fumihiko Kaminari
ProfessorFaculty of Science and Technology, Department of Electrical EngineeringKotaro Oka
ProfessorFaculty of Science and Technology, Department of Biosciences and Informatics