RESOURCES
At Nakagawa Group, we specialize in pioneering imaging and experimental technologies. In the realm of high-speed imaging, also known as slow-motion photography, we stand out as one of the few groups globally capable of capturing fast phenomena in a single shot across extensive time domains—from femtoseconds (10^(-15) seconds) to milliseconds (10^(-3) seconds).
Additionally, we have developed distinctive microscopic and visualization technologies, including acoustic field mapping, 3D particle image velocimetry, wide-field light-sheet microscopy, and ultrafast fluorescent ratiometric imaging. These technologies based on photonics and acoustics allow us to explore diverse scientific phenomena and contribute to advancements in fields like physics, chemistry, life sciences, and medical research.
Our group possesses fundamental facilities that enable interdisciplinary research, linking various scientific disciplines in our pursuit of knowledge and innovation.
Special equipment
STAMP (sequentially timed all-optical mapping photography)
STAMP (Sequentially Timed All-optical Mapping Photography) is an ultrafast imaging technique that allows for the acquisition of motion pictures of ultrafast events in the timescales of femtoseconds to nanoseconds. The specifications of the current setup are as follows:
Frame interval (the inverse of the frame rate): 35 fs - 10 ns
Number of frames: max. 18
Center wavelengths of illumination: 400 nm, 800 nm
References
K. Nakagawa, Doctoral Dissertation (2014): OpenPDF (It is written in poor English. Sorry!)
K. Nakagawa et al., Nature Photonics (2014): https://doi.org/10.1038/nphoton.2014.163
Microscope
(Description Under Construction.)
General equipment
High-speed cameras and illuminations
Comersialized high-speed video cameras and high-speed illuminations are available.
Minimum frame interval: 100 ns
Minimum exposure time: 10 ns
Number of Frames: over 100
Other cameras
Other scientific cameras are available.
High-sensitivity cameras for observing weak luminescence phenomena like fluorescence and bioluminescence.
Intensified CCD: Fast gating and electronic amplification.
High-pixel resolution cameras for wide-field imaging.
VIS-to-NIR InGaAs cameras.
Lasers
We are using lasers for imaging and generating acoustic pulses.
Ti:S laser with CPA: Pulse width of 35 fs, center wavelength of 800 nm, bandwidth of 35 nm, 3 mJ, 1 kHz.
OPA with the Ti:S laser: Tunable wavelength between 290 nm to 2700 nm.
Q-Switched Nd:YAG lasers: 355 nm, 532 nm, 1064 nm, pulse width of 5 ns, max. 170 mJ@1064 nm.
Q-Switched Ho:YAG laser: 2080 nm, 100 mW.
CW lasers: 405 nm, 445 nm, 460 nm, 488 nm, 532 nm, 633 nm, 808 nm.
Ultrasounds and shock waves
We also utilize piezoelectric-based ultrasound sources and electrical discharge-based shock wave sources.
Ultrasonic Transducers: These are of the immersion, focusing type, operating with frequencies of 1 MHz, 2 MHz, and 5 MHz.
Function Generators and RF Power Amplifiers.
Hydrophones: Typical cutoff frequency of 10 MHz.
Medical Ultrasound Diagnostic Equipment.
Shock Wave Sources: Max. 5 kV and 20 kV electrical discharge.
Focusing Acoustic Reflectors: We have fabricated these reflectors.
Optics and electronic devices
Instruments for photonics research:
High-power LED light engine: Wavelengths of 340 nm and 385 nm.
Spatial light modulators: 1920 x 1080 resolution, operational in the wavelength range of VIS, 800 nm or 1064 nm.
Digital mirror device: 1920 x 1080 resolution, 5.4 um micromirror pitch.
Acoustic-optic modulator: Operates at a wavelength of 1080 nm and has a frequency of 80 MHz.
Photodetectors: Operational in the wavelength range of VIS or NIR, fast response photodetectors, APD, balanced photodetector.
Spectrometers: Functional in the wavelength range of VIS or NIR.
Mixed signal oscilloscope: Analog bandwidth of 23 GHz, the sample rate of 50-100 GS/s.
Pulse delay generators: Models DG645, DG535.
Specialized optics: Slicing mirrors, microlens array, etc.
Other basic facilities
In addition to the facilities listed below that our group possesses, we also utilize shared facilities at the university.
Microscopes: Olympus IX73 Inverted Microscope for cell observation, and Nikon Ti2-U microscope for custom use.
Equipment for cell culture: Cell culture hood, incubator, refrigerator (4°C), freezer (-20°C), ultradeep freezer (-80°C), water bath, centrifuge, and autoclave.
Equipment for chemical synthesis: Fume hood, Ar gas, precision electronic balance, evaporator, and sonicator.
Equipment for sample/device preparation: Spin coater, UV illumination, heating plate, vacuum chamber, etc.
Machine tools: Drilling machine, turning machine, milling machine, grinding machine, etc.
Computer servers.
Research data
(Description Under Construction.)