Research Activities

1. Development and Fundamental Understanding of Ultrashort Pulse Laser Processing Technologies

Recent advances in laser technology have enabled the generation of high-intensity, highly stable ultrashort pulse lasers. These lasers are not only capable of conventional micromachining such as drilling and cutting, but also allow for the fabrication of intricate three-dimensional microstructures on the micrometer scale—structures that are extremely difficult to produce by other means. Since these fabricated structures can be smaller than the wavelengths of electromagnetic waves such as millimeter and terahertz waves, appropriately designed structures can function as novel electromagnetic metamaterials for wave control. In this research, we are developing fabrication techniques for such 3D structures using ultrashort pulse lasers, while also exploring their application as functional materials in diverse fields such as astrophysics and next-generation wireless communication (Beyond 5G).

At the same time, many fundamental questions remain unresolved regarding the physical mechanisms by which materials are damaged or modified by ultrashort pulse laser irradiation. Why do materials break down under exposure to intense laser light? To address this question, we are developing advanced optical control techniques and various measurement methods to investigate the mechanisms of laser-induced material damage. Through this research, we aim not only to gain a deeper understanding of laser–matter interaction, but also to apply these insights to the further advancement of laser processing technologies.

Members：Kuniaki Konishi, Haruyuki Sakurai, Mizuho Matoba, Shotaro Kawano
Keywards：Ultrashort pulse laser processing, Metasurface, Terahertz technology

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3. Development of Advanced Spectroscopic Technologies

・Ultrafast Spectroscopy Using Ultrashort Pulse Lasers

In recent years, technologies for controlling the amplitude and phase of ultrashort laser pulses have advanced dramatically. Notable milestones include the generation of optical frequency combs (Nobel Prize in Physics, 2005) and attosecond pulse light (Nobel Prize, 2023). We are developing novel spectroscopic techniques that harness the unique properties of ultrashort pulses. Specifically, we have realized cutting-edge methods such as dual-comb spectroscopy using two optical frequency combs, and time-stretch spectroscopy—a high-repetition-rate single-pulse technique—achieving some of the world’s fastest spectroscopic measurements.
We also develop high-performance measurement systems by combining optical communication technologies (such as optical fibers and high-speed modulators) with nonlinear optics. These original techniques are being applied to chemical and biological analysis, including the characterization of functional materials and biological samples.

Members: Takuro Ideguchi, Kazuki Hashimoto, Zicong Xu
Keywords: Ultrashort Pulses, Optical Frequency Combs, Spectroscopy, Nonlinear Optics

・Label-Free Microscopy and Life Sciences

Microscopic observation of biological specimens such as cells and tissues is a fundamental technique in life science research. While fluorescence imaging using stained samples is common for visualizing specific biomolecules, staining poses several limitations. In recent years, label-free imaging techniques—which eliminate the need for staining—have advanced rapidly. We are developing advanced chemical imaging techniques that utilize molecular vibrations in biomolecules, as well as scattering microscopy based on the optical scattering properties of samples. For example, we have developed an infrared microscope with the world’s highest spatial resolution, capable of visualizing subcellular structures within bacteria through vibrational imaging. Using our original imaging technologies, we are also conducting fundamental studies in biophysics, such as investigating intracellular thermal phenomena (in collaboration with the Graduate School of Pharmaceutical Sciences).

Members: Takuro Ideguchi, Keiichiro Toda
Keywords: Imaging, Microscopy, Label-Free, Life Sciences, Biophysics

・Quantum Optical Measurement

Research on next-generation technologies based on the principles of quantum mechanics such as quantum computings gaining attention. In the field of optical measurement, including spectroscopy and imaging, quantum technologies are also being explored to enhance performance. We are working on the development of optical measurement techniques that incorporate quantum optics to achieve new functionalities and superior performance.

Members: Takuro Ideguchi, Kazuki Hashimoto, Zicong Xu
Keywords: Quantum Optics, Spectroscopy, Imaging

・Computational Optical Measurement

With the remarkable growth of computational power, data analysis methods that utilize information science are being widely developed. These approaches are also being integrated into optical measurement. We are developing computational optical measurement technologies that enhance performance and simplify measurements by combining innovations in optical hardware with information science techniques. Specifically, we are working on spectroscopic and imaging methods that leverage compressive sensing and machine learning, in collaboration with the Graduate School of Information Science and Technology.

Members: Takuro Ideguchi, Keiichiro Toda
Keywords: Computational Imaging, Compressive Sensing, Machine Learning