Associate Professor

Keshav D​ani

kmdani ('at'

[November 2011 - ]

I joined OIST as an Asst. Professor in Nov. 2011 after completing a Director’s Postdoctoral Fellowship at the Center for Integrated Nanotechnologies at Los Alamos National Laboratory. I graduated from UC Berkeley in 2006 with a PhD in Physics under the supervision of Prof. Daniel Chemla. I obtained a BS from Caltech in Mathematics with a senior thesis in Quantum Information Theory under John Preskill and Hideo Mabuchi. My recent research interests have been in studying the nonlinear and ultrafast properties of 2D and energy materials, terahertz spectroscopy and devices, and applications of femtosecond pulses to neuroscience. 

Keshav Dani


Research Administrator

Yumi Ito


[April 2015 - ] 

I began my career at Texas State University in September 2004 as a part-time editorial assistant and joined the staff full-time for Dani Unit as an administrative assistant in April 2015. My key element for the unit is caring and warmth in assisting them in achieving their objectives from administrative side, and in helping them have a laugh and fun. Favoring trip and movies, I enjoy spending time with family and friends. An oni-wife and a mother of a King-Kong baby boy.


Staff Scientists

Michael Man (‘at’

[December 2017 - ]

I received both my master and PhD degrees from the Hong Kong University of Science and Technology (HKUST). My main research interest is in the growth and characterization of nanostructures/ultrafilm films using a powerful and versatile technique called low energy electron microscopy and photoemission electron microscopy (LEEM/PEEM). LEEM/PEEM is capable of performing time and spatially resolved structural, electronic and chemical state measurements at spatial resolution down to the nanometer range. With this instrument, for example, we can study the correlation between morphology and band structure in inhomogeneous nanostructures such as in few layer graphene; we can also examine the surface magnetic state and image the dynamics in magnetic domain structure in variety of magnetic nanomaterials. I joined Prof. Dani’s group in OIST in December 2012. Together, we seek to combine my experience in LEEM/PEEM microscopy with the group’s expertise in ultrafast spectroscopy techniques. One of our goals is in the investigation and visualization of the ultrafast dynamics in nanostructures.


Michael Man

Julien Madéo


[July 2019 - ]

I did my PhD in Laboratoire Pierre Aigrain at Ecole Normale Supérieure in Paris where I studied quantum cascade lasers using THz time-domain spectroscopy and their optical nonlinearities for wavelength conversion. In 2012, I visited OIST for a few months to provide help in building the first lab of the FSU. Then, I came back to Paris for two years in Matériaux et Phénomènes Quantiques, Paris 7 University to study microcavity THz sources and InAs/AlSb based quantum cascade lasers. Since 2014, I am back in the FSU and my current interests cover: THz optoelectronics and devices, ultrafast and nonlinear optics as well as 2D materials and heterostructures.



Postdoctoral Researchers

Christopher Petoukhoff

christopher.petoukhoff ('at'

[June 2017 - ]

I obtained my Ph.D. from Rutgers University (NJ, USA) in Materials Science and Engineering in the group of Deirdre O'Carroll. The focus of my dissertation was on designing plasmonic metasurfaces for light-trapping in thin-film photovoltaics. I visited the Femtosecond Spectroscopy Unit for 10 weeks during the summer of 2015, and returned as a Special Research Student from Jul 2016 - Apr 2017. I started as a post-doc in Jun 2017, and my current research interests include: ultrafast dynamics of energy materials, van der Waals heterostructures, organic semiconductors, and plasmonic light-trapping.


Arka Karmakar

Arka.Karmakar ('at'

[April 2019 - ]

I finished my PhD in Electrical Engineering from University at Buffalo (SUNY Buffalo) in February 2019 under the supervision of Prof. Erik Einarsson. My PhD research work was focused on CVD growth of graphene and fabrication of metal-graphene hybrid antenna array for THz communications. The project was funded by US Air Force Research Laboratory (AFRL). After completing PhD, I joined OIST as a postdoctoral researcher in Dani Unit. Here in Okinawa, my research is focused on fabrication of 2D vdW heterostructures with clean interfaces for studying optoelectronic properties.


David Bacon

David.Bacon ('at'

[August 2019 - ]

I received the M.Eng degree and PhD in electronic and electrical engineering from the Pollard Institute at the University of Leeds, UK, in 2013 and 2017 respectively. The focus of the master project was on the characterisation of terahertz quantum cascade laser active regions. This was then expanded upon during my PhD where I investigated the time-resolved gain dynamics within the device using terahertz time-domain spectroscopy. From this work, I awarded a 2-year-long EPSRC fellowship prize within the Pollard Institute, where I studied the use of photoconductive array structures for the generation of high-field THz radiation. Following that, I joined the femtosecond spectroscopy unit at OIST in August 2019. My research interests include the generation and application of high-field THz radiation, terahertz time-domain spectroscopy and ultrafast electro-optics.



PhD Students

Viktoras Lisicovas

viktoras.lisicovas ('at'

[March 2014 - ]

I graduated from Jacobs University in Bremen, Germany with a degree in Biochemistry and Cell Biology. Later, I have worked in the Laboratory of Biophysics and Applied Pharmacology at ENS Cachan. At OIST my interest lies in studying the basic mechanisms of memory in small networks. I joined Femtosecond Spectroscopy Unit to pursue improvements in optical imaging techniques for basic neuroscience applications.

Andrew Winchester

andrew.winchester ('at'

[September 2015 - ]

I recieved my BSc and MSc in physics from Southern Illinois University, Carbondale. While there, I spent time researching various nanomaterials, from carbon nanotubes and graphene to molybdenum disulfide, including ways to produce them and their applications in energy storage. Here in Okinawa, I plan to continue studying various nanomaterials in the Femtosecond Spectroscopy Unit. In particular, I want to study their ultrafast and nonlinear optical properties and work to develop next-generation optoelectric devices which rely on these novel properties.


Vivek Pareek

vivek.pareek ('at'

[September 2016 - ]

I received my dual BS-MS degree from IISER-Kolkata, India. During my master's thesis, I studied the high pressure dependence of multiferroics using Raman spectroscopy. My rotation project with FSU has increased my interest in the field of femtosecond spectroscopy. Therefore, I decided to join FSU to pursue my PhD. I will be studying the optical properties of 2D semiconductors for my thesis.


Joel Pérez Urquizo

joel.perezurquizo ('at'

[September 2017 - ]

I got both my bachelor and master degree at “Universidad Nacional Autónoma de México (UNAM)”. I majored in Telecommunications Engineering where I worked at the microwave regime designing and fabricating planar resonant devices for near field microwave microscopy. For my masters I scaled up in frequencies and worked in the THz regime designing and fabricating photoconductive probes for THz near field imaging. Today I’m a PhD student of the 2016 class at OIST and I’m joining the Femtosecond Spectroscopy Unit where I will focus on the research of Quantum Cascade Lasers for THz generation.


Sofiia (Sonya) Kosar

sofiia.kosar ('at'

[September 2018 - ]

I began my PhD studies at OIST in September 2017 after obtaining my master’s degree in solid state physics from the Chernivtsi National University in Ukraine. My thesis was focused on energy materials, in particular, on semiconducting materials for photocatalytic water splitting under solar illumination. I have also spent one year at the University of Groningen in Netherlands studying nanoscience during my masters. I joined FSU as a rotation student in January 2018 after finishing my rotation project on perovskite solar cells. Here I am planning to continue studying energy materials by doing transient absorption spectroscopy experiments on two-dimensional organic heterostructures.



Rotation Students

Xing Zhu

[May 2019 - ]


I received my bachelor from South University of Science and Technology of China. I join the femtosecond spectroscopy unit as research intern for six months. Previously I worked on the magnetic and optical properties of new-rising 2D materials from first-principles calculation. And now my research interests focus on the terahertz and its applications in imaging and spectroscopy. In FSU, I’ll study strong-field/broadband THz generation and THz spectroscopy of magnetic materials.



Special Research Students

Chakradhar Sahoo

chakradhar.sahoo ('at'

[May 2018 - ]

I finished my M.Sc (Physics) at University of Hyderabad (UoH) with “Laser Physics” specialization. While there, I performed my research project on Nonlinear Optics, Laser direct writing on semiconductors. After, I joined as a research scholar (PhD) in school of Physics at UoH and was continuing “ultrafast molecular dynamics via pump-probe technique”. Here, I joined FSU as a Special Research Student and am going to work on “ultrafast dynamics of 2d van der Waals heterostructures through micro pump-probe experiment”.


Research Interns

Lincoln Weber ('at'

[May 2019 - ]

I am currently working on my bachelor's degree from Southern Illinois University - Carbondale (USA) as part of Dr. Saikat Talapatra's group. During the summer of 2018 I worked with Prof. Masayoshi Tonouchi to do THz-TDS with aligned carbon nanotubes. I will be visiting the Femtosecond Spectroscopy Unit from May to August 2019 as a research intern to do work involving THz measurements of perovskite materials.

Mohamed Abdelrasoul

mohamed.abdelrasoul ('at'

[Dec. 2018 - ]

I received my master’s degree in optics and photonics from Karlsruhe Institute of Technology (KIT), Germany, then I joined Zewail City of Science and Technology in Egypt as a research assistant. I worked on setting up the four-dimensional ultrafast electron microscopy (4D-UEM) by building and integrating an ultrafast pump-probe optical setup with a modified transmission electron microscope, where I found it a fascinating as well as a challenging task. At FSU, I am going to pursue my interest in probing ultrafast dynamics with the hope of extending the capabilities of both the ultrafast laser systems and the photoemission electron microscope (PEEM).




Nicholas Chan

nicholas.chan2 ('at'

[June 2019 - ]

I recently graduated from Northeastern University with a B.S. in Electrical Engineering.  As part of Northeastern's co-op program I researched point-to-point communications at the Wright-Patterson Air Force Research Lab (AFRL Rome) in 2017 and 2D semiconductors with Dani Unit in 2018.  I am now returning to Dani Unit as a research technician to assist in 2D Van der Waals device fabrication.


Oksana Kravchyna

oksana.kravchyna ('at'

[June 2019 - ]

I received my PhD at B.Verkin Institute for Low Temperature Physics and Engineering (ILTPE, Ukraine) in Physical and Mathematical Sciences. During my PhD work at the research institution, I studied low-dimensional systems. I have investigated a series of metal-organic compounds. As a result of my work, I was able to determine the magnetic structure of these compounds and calculate the value of magnetic interaction between magnetic ions depending on changing exchange paths. I joined the Dani Unit in June 2019 as a technician. My job is to provide all the required technical, safety, and administrative support to enable the laboratory to function effectively.

Visiting Researchers

Abdullah Al-Mahboob

Abdullah.AlMahboob ('at'

[June 2019 - ]

I am visiting Femtosecond Spectroscopy Unit (Keshav Dani Unit) for learning and exploring Novel Ultra-Fast Photo-electron Spectro-microscopy technique developed by Dani Unit. I obtained Doctor of Science from Tohoku University, Sendai, Japan where I studied organic molecular film growth employing low energy electron microscope (LEEM/PEEM), STM and complementary DFT calculations. Following my doctoral study, I worked at Tohoku University (2007-2009) as assistant professor and continued my study on organic molecular materials. Subsequently, I worked at Brookhaven National Laboratory (2009-2013), USA as research associate in interface science and catalysis and user program of PEEM/LEEM endstation of CFN at NSLS, at the University of Liverpool (2014-2016), UK as research coordinator of intermetallic alloys and quasicrystalline compounds and Elettra Sincrotrone-Trieste (2016-2017), Italy as spectromicroscopy beamline scientist, at the City University of New York (2018-2019) as adjunct faculty in energy science. Currently (2018- ) I am teaching energy and power management analysis in Engineering and Technology Management Program at SUNY-Farmingdale State College.



Previous Group Members

Previous Rotation Students


Page last updated on Aug. 8, 2019 (CP).