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The article “Terahertz, a Technology That Can See Through Walls!” published by Substance on January 9, 2018, presented terahertz and gave an overview of the different applications for these spectral waves. This article presents the terahertz team led by François Blanchard and the research work being done in the field.
Terahertz research began at Montreal’s École de technologie supérieure (ÉTS) on January 5, 2015, when Professor François Blanchard took up his duties. Since then, Professor Blanchard has set up a team of researchers working in the very first terahertz laboratory at ÉTS. Currently, four Ph.D. students, two postdoctoral fellows and one master’s student make up the ÉTS terahertz team.
All researchers on the terahertz team have a main area of research and a secondary one: they carry out their research on the second one when they have no experiments to conduct or they are waiting for results. This means that the researchers all have a plan A and a plan B. They are also encouraged to work as a team to share their knowledge and publications.
Mariia Zhuldybina holds a Bachelor’s degree and a Master’s degree in Physics from the Moscow Institute of Physics and Technology; she is currently pursuing Ph.D. studies at ÉTS under the direction of Professors François Blanchard and Ricardo Zednick.
Her two areas of research are the characterization of printable electronic materials with non-contact and in situ terahertz waves in order to determine their conductivity properties, and to establish print quality. Current techniques used to characterize this type of circuit involve either observing their colours through reflectivity―a non-contact method that does not permit establishing the conductivity of the materials―or taking measurements with a voltmeter―a method that requires an operation shutdown.
Fatemeh Amirkhan, Ph.D. student at ÉTS under the direction of professors François Blanchard of ÉTS and Tsuneyuki Ozaki of INRS, is an electrical engineer who also holds a Master’s degree in telecommunications. She was a research assistant for several years during which she carried out material characterization tasks, and worked with special optical fibres and photonic crystals in the telecommunications field.
Her research focuses on terahertz wave generation and detection, and spectroscopy of new materials. Her goal is to create new methods to generate terahertz waves with new materials. She is working in collaboration with Professor Sylvain Cloutier and his team, who are developing new ferroelectric materials with electro-optical properties. These materials convert electrical information into optical modulations that can be used to perform terahertz wave detection. Together, they are designing materials with very high electro-optical coefficients to increase the sensitivity of measuring instruments. Fatemeh Amirkhan is also using spectroscopy to study these new materials. Her goal is to establish the optimum optical wavelength for conversion into terahertz waves. She uses the Time-domain spectroscopy method, which measures the wave phase amplitude transmitted in a material.
Mehraveh Javan, Ph.D. candidate under the direction of professors François Blanchard and Mohamed Cheriet, holds a Bachelor’s degree in Physical Sciences from the University of Tehran and a Master’s degree in Physics from the University of Alberta, where she was teaching and working as a research assistant. She is a physics theorist (plasma, radiation, etc.) and a Matlab software specialist.
Her research focuses on compressed sensing, which resembles image compression. JPEG preserves good image quality by using a small number data from the source image. This approach also works in detection: instead of measuring all the information in a signal, it is possible to measure a fraction and obtain a signal almost identical to the source signal. Since terahertz sources are extremely expensive and detection requires a relatively long time to acquire all the information, it is important to have tools that facilitate and accelerate the work and that require little time. Mehraveh Javan’s math skills and her experience in data processing are put to good use in the terahertz team.
She is also working with Professor Mohamed Cheriet and his team on dating ancient books using terahertz waves
Joel Edouard Nkeck
Joel Edouard Nkeck, Ph.D. candidate at ÉTS whose research is directed by Professor François Blanchard and researcher Riad Nechache, earned his Bachelor’s degree from the African Institute for Mathematical Sciences in Cameroon and a Master’s degree in optics from the university Nice-Sophia-Antipolis in France.
The terahertz laboratory will soon be equipped with a fibre laser to be used in the development of new terahertz wave generation techniques. Joel Edouard Nkeck will collaborate with Dr. Riad Nechache (Professor Sylvain Cloutier’s team) for the development of new materials and a new type of terahertz microscopy.
He will also work on an INRS research project funded by an NSERC innovation fund to which the terahertz team is working. Joel Edouard Nkeck will develop new terahertz sources using a fiber laser in order to scale-up more powerful lasers.
Kousuke Murate earned a Ph.D. from the Electrical Engineering Department of Nagoya University in Japan. He began his terahertz research during his undergraduate studies, and pursued master’s and Ph.D. studies with Professor Kodo Kawase (a pioneer in the field of terahertz waves), in partnership with Hamamatsu and the Riken research organization in Japan.
Kousuke Murate was admitted to a six-month internship at ÉTS with the terahertz team. Such collaboration between Nagoya University and ÉTS is an example of the exchange program that allows ÉTS students access to the Japanese university.
During his internship, Kousuke Murate and the terahertz team developed a new method to control the wavefront of ultra-short optical pulses (20 femtoseconds) using electromechanical micromirrors (MEMS). At the same time, Kousuke Murate is working on an article that demonstrates how applying this pulse generates terahertz waves.
Post doctorate fellow Xavier Ropagnol, who holds a Ph.D. in physics from INRS EMT, is a researcher at INRS with Professor Tsuneyuki Ozaki, and is part of the ÉTS terahertz team. He specializes in intense terahertz wave generation using other wave generation techniques, such as photoconductive antennas.
Luis Sanchez Mora
Luis Sanchez Mora is currently completing a professional master’s degree in engineering at ÉTS. As part of his studies, the terahertz research he conducted during three full-time semesters was equivalent to a master’s degree in applied science. Within a team of INRS researchers, he worked successfully on the development of a new electro-optical sampling technique for terahertz wave measurement using the Labview programming language. His knowledge of the language is useful in his current role as a research assistant within the terahertz team.
Upcoming Research at the Terahertz Laboratory
As the actual ÉTS terahertz research laboratory is a small one, research priorities are focused on new methods that can generate and detect terahertz waves, and on the simulation of light-matter interactions at these frequencies. When the laboratory, research team and terahertz funding increase (in the very near future), part of the laboratory could be assigned to industry needs.
Research Projects Available—Terahertz Team
- Several 9 and 15-credit projects for students enrolled in a Master’s degree in Engineering at ÉTS, in Electrical or Computer Engineering with an interest in physics. These projects will use LabView programming and instrument control to bring an element from the system to maturity.
- Other master’s research projects for students interested in terahertz wave propagation. These students must demonstrate good technical skills.
- A Ph.D. thesis project on new types of terahertz sources in relation to an Innovation project obtained by INRS professors in which the ÉTS terahertz team is taking part.