Nav: Home

A laser, a crystal and molecular structures

September 27, 2019

Researchers have built a new tool to study molecules using a laser, a crystal and light detectors. This new technology will reveal nature's smallest sculptures - the structures of molecules - with increased detail and specificity.

"We live in the molecular world where most things around us are made of molecules: air, foods, drinks, clothes, cells and more. Studying molecules with our new technique could be used in medicine, pharmacy, chemistry, or other fields," said Associate Professor Takuro Ideguchi from the University of Tokyo Institute for Photon Science and Technology.

The new technique combines two current technologies into a unique system called complementary vibrational spectroscopy. All molecules have very small, distinctive vibrations caused by the movement of the atoms' nuclei. Tools called spectrometers detect how those vibrations cause molecules to absorb or scatter light waves. Current spectroscopy techniques are limited by the type of light that they can measure.

The new complementary vibrational spectrometer designed by researchers in Japan can measure a wider spectrum of light, combining the more limited spectra of two other tools, called infrared absorption and Raman scattering spectrometers. Combining the two spectroscopy techniques gives researchers different and complementary information about molecular vibrations.

"We questioned the 'common sense' of this field and developed something new. Raman and infrared spectra can now be measured simultaneously," said Ideguchi.

Previous spectrometers could only detect light waves with lengths from 0.4 to 1 micrometer (Raman spectroscopy) or from 2.5 to 25 micrometers (infrared spectroscopy). The gap between them meant that Raman and infrared spectroscopy had to be performed separately. The limitation is like trying to enjoy a duet, but being forced to listen to the two parts separately.

Complementary vibrational spectroscopy can detect light waves around the visible to near-infrared and mid-infrared spectra. Advancements in ultrashort pulsed laser technology have made complementary vibrational spectroscopy possible.

Inside the complementary vibrational spectrometer, a titanium-sapphire laser sends pulses of near-infrared light with the width of 10 femtoseconds (10 quadrillionths of a second) towards the chemical sample. Before hitting the sample, the light is focused onto a crystal of gallium selenide. The crystal generates mid-infrared light pulses. The near- and mid-infrared light pulses are then focused onto the sample, and the absorbed and scattered light waves are detected by photodetectors and converted simultaneously into Raman and infrared spectra.

So far, researchers have tested their new technique on samples of pure chemicals commonly found in science labs. They hope that the technique will one day be used to understand how molecules change shape in real time.

"Especially for biology, we use the term 'label-free' for molecular vibrational spectroscopy because it is noninvasive and we can identify molecules without attaching artificial fluorescent tags. We believe that complementary vibrational spectroscopy can be a unique and useful technique for molecular measurements," said Ideguchi.
-end-
Research Paper

Hashimoto K., Badarla V.R., Kawai A., and Ideguchi T. (27 September 2019). Complementary Vibrational Spectroscopy. Nature Communications. DOI: 10.1038/s41467-019-12442-9 http://dx.doi.org/10.1038/s41467-019-12442-9

Related Links

Ideguchi Laboratory: https://takuroideguchi.jimdo.com/

Department of Biological Sciences: http://www.bs.s.u-tokyo.ac.jp/english/

Graduate School of Science: https://www.s.u-tokyo.ac.jp/en/

Twitter: @IdeguchiTakuro

Research contact

Associate Professor Takuro Ideguchi
Institute for Photon Science and Technology, The University of Tokyo
Tel: +81-(0)3-5841-1026
Email: ideguchi@gono.phys.s.u-tokyo.ac.jp

Press Contact

Ms. Caitlin Devor
Division for Strategic Public Relations, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, JAPAN
Tel: +81-(0)3-5841-0876
Email: press-releases.adm@gs.mail.u-tokyo.ac.jp

About the University of Tokyo

The University of Tokyo is Japan's leading university and one of the world's top research universities. The vast research output of some 6,000 researchers is published in the world's top journals across the arts and sciences. Our vibrant student body of around 15,000 undergraduate and 15,000 graduate students includes over 4,000 international students. Find out more at http://www.u-tokyo.ac.jp/en/ or follow us on Twitter at @UTokyo_News_en.

University of Tokyo

Related Laser Articles:

A laser for penetrating waves
The 'Landau-level laser' is an exciting concept for an unusual radiation source.
Laser light detects tumors
A team of researchers from Jena presents a groundbreaking new method for the rapid, gentle and reliable detection of tumors with laser light.
The first laser radio transmitter
For the first time, researchers at Harvard School of Engineering have used a laser as a radio transmitter and receiver, paving the way for towards ultra-high-speed Wi-Fi and new types of hybrid electronic-photonic devices.
The random anti-laser
Scientists at TU Wien have found a way to build the 'opposite' of a laser -- a device that absorbs a specific light wave perfectly.
Laser 'drill' sets a new world record in laser-driven electron acceleration
Combining a first laser pulse to heat up and 'drill' through a plasma, and another to accelerate electrons to incredibly high energies in just tens of centimeters, scientists have nearly doubled the previous record for laser-driven particle acceleration at Berkeley Lab's BELLA Center.
Laser physics: Transformation through light
Laser physicists have taken snapshots of how C60 carbon molecules react to extremely short pulses of intense infrared light.
Laser-induced graphene gets tough, with help
Laser-induced graphene created at Rice University combines with many materials to make tough, conductive composites for wearable electronics, anti-icing, antimicrobial applications, sensors and water treatment.
How molecules teeter in a laser field
When molecules interact with the oscillating field of a laser, an instantaneous, time-dependent dipole is induced.
Laser blasting antimatter into existence
Antimatter is an exotic material that vaporizes when it contacts regular matter.
New laser advances
Lasers are poised to take another step forward: Researchers at Case Western Reserve University, in collaboration with partners around the world, have been able to control the direction of a laser's output beam by applying external voltage.
More Laser News and Laser Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Uncharted
There's so much we've yet to explore–from outer space to the deep ocean to our own brains. This hour, Manoush goes on a journey through those uncharted places, led by TED Science Curator David Biello.
Now Playing: Science for the People

#556 The Power of Friendship
It's 2020 and times are tough. Maybe some of us are learning about social distancing the hard way. Maybe we just are all a little anxious. No matter what, we could probably use a friend. But what is a friend, exactly? And why do we need them so much? This week host Bethany Brookshire speaks with Lydia Denworth, author of the new book "Friendship: The Evolution, Biology, and Extraordinary Power of Life's Fundamental Bond". This episode is hosted by Bethany Brookshire, science writer from Science News.
Now Playing: Radiolab

Dispatch 2: Every Day is Ignaz Semmelweis Day
It began with a tweet: "EVERY DAY IS IGNAZ SEMMELWEIS DAY." Carl Zimmer – tweet author, acclaimed science writer and friend of the show – tells the story of a mysterious, deadly illness that struck 19th century Vienna, and the ill-fated hero who uncovered its cure ... and gave us our best weapon (so far) against the current global pandemic. This episode was reported and produced with help from Bethel Habte and Latif Nasser. Support Radiolab today at Radiolab.org/donate.