About me
I am professor of optoelectronics (semiconductor technology). Optoelectronics serves as the core technology for the majority of light driven photonics applications. Optoelectronic devices are used to transform electrons into photons, modulate and amplify light beams, transfer photonic signals to electronic domains, or convert solar light to energy.
My personal motto is “MAKE A DIFFERNCE!”. I follow this by identifying early stage emerging areas of research concerning III-V optoelectronics materials and novel device concepts. I target long-term impact by establishing technology development roadmaps starting from basic material science and ending with proof-of-concept applications, such as the use of semiconductor lasers in dermatology, sensing of environmental pollutants, and high efficiency solar energy conversion.
OSA Fellow SPIE Fellow
Responsibilities
I am heading the research work at the “ORC-team” (Optoelectronics Research Center ), part of photonics community in Physics Unit. ORC is one of the leading optoelectronics research groups in Europe with more than 30 years of activity centered on the use of molecular beam epitaxy and the development of novel optoelectronic devices, such as laser diodes or solar cells. It is also the cradle of laser industry in Tampere and Finland.
I am responsible for three MSc-level courses in the area of optoelectronics and photonics and I act as lead supervisor or co-supervisor for 12 PhD students. I am PI of an ERC AdG project (AMETIST), and several other projects funded by the Academy of Finland, Business Finland, the European Commission (H2020), and the European Space Agency.
Field of expertise
Molecular beam epitaxy, optoelectronic devices, semiconductor lasers, high-efficiency photovoltaics, ultrafast semiconductors, innovation and entrepreneurship.
Research topics
1. Topics concerning novel optoelectronics materials: InAs-based quantum nanostructures for nonclassical light sources; epitaxy of novel bismides compounds (GaSbBi and GaAsBi).
2. Topics concerning novel devices: semiconductor lasers (VCSEL) arrays for 3D sensing and datacenters; semiconductor lasers for eye-safe LIDAR and mid-IR sensing; high-efficinecy multi-junction solar cells with lattice-matched materials (i.e. GaInNAsSb).
3. Topics concerning technology platforms: hybrid integration of III-V components on silicon-photonics platform (in collaboration with VTT); monolithic integration of III-V compounds on Si/Ge.
4. Topics concerning photonics applications: eye-safe time-of-flight LIDAR; mid-IR sensing; photovoltaic converter for optical energy transfer; use of semiconductor frequency converted yellow lasers in dermatology and ophthalmology.
Research unit
Physics / Photonics
Research fields
Optoelectronics technology, photonics
https://research.tuni.fi/orc/
Research career
2008 – Professor, Tampere University (Tampere University of Technology until 2018)
2005 – 2008 Senior researcher, Optoelectronics Research Centre, Tampere University of Technology
2003 – 2005 Postdoc, Optoelectronics Research Centre, Tampere University of Technology
1999 – 2002 Post-grad student, Optoelectronics Research Centre, Tampere University of Technology
1997 – 1999 Teaching assistant (optoelectronics), University POLITEHNICA of Bucharest, Romania
Top achievements
1. Over 230 refereed journal articles, h-index = 30 WoS; 32 Scopus; 38 Google Scholar
2. More than 35 invited talks at international conferences (e.g. Photonics West, CLEO, MRS, EuroMBE)
3. Frequently invited for seminars at leading photonics research laboratories (mainly in Europe)
4. Author and co-author of 9 book chapters, 4 granted patents, and several patent applications
5. Supervisor of more than 25 postgraduate students: 15 theses completed, 3 to be completed in 2021 and 3 others planned for completion in 2022; 5 student awards at major international conferences (EU-PVSEC 2015, Photonics Europe 2014, Euro-MBE 2013, Northern Physics 2011, Euro-MBE 2011); three student awards for "The Best PhD-thesis in photonics/technology” (V. Polojärvi, 2017; A. Aho, 2016; T. Hakkarainen, 2015).
Funding
Current grantee of an ERC Advanced Grant (AMETIST) for developing high-efficiency solar cells (2.5 M€), two H2020 projects, one Business Finland project, one Academy of Finland project, one ESA project, and two bilateral projects with industry (750 k€).
Mission statement
My vision is powered by integration of multidisciplinary research in material science, new photonics technologies, and photonics applications. The pinnacle of these developments is to see the research work providing innovative solutions for real-world applications. To this end, I follow in the footsteps of the optoelectronics technology pioneers in Tampere, continuing our strong tradition for establishing high-tech photonics spin-offs and technology transfer programs. I do this by fostering innovation driven activities within the research group while striving to improve our scientific and educational output.
I am a strong advocate of entrepreneurship in research as the most direct link to achieve societal impact and motivate the efforts for advancing the frontiers of science and technology (I am co-founder of three spin-offs resulted from research programs I initiated, and I collaborate with a large number of industrial research partners in Finland and abroad).
Main positions of trust
2015 – 2021 Topical Editor, Optics Letters, OSA
2015 – Topical Editor, Journal of the European Optical Society, EOS
2015 – Permanent member of the Scientific Board of the European MBE Workshop
2016 – Chairmen of the Academic Advisory Board of Photonics Finland
2018 – Editorial Board, Optics and Lasers section, Journal of Applied Sciences, MDPI
2018 – Permanent member of the International Advisory Board, International MBE Conference
2019 – Member of Photonics21 Board of Stakeholder, representing Tampere University
2019/’17/’15 – External reviewer for European Research Council Executive Agency (ERC grants)
Founder and Director of the International Summer School “New Frontiers in Optical Technologies ” (2001/2003/2005/2007/2009/2011/2013/2015/2017/2019)
Chairman of the Board at Vexlum Oy , Picophotonics Oy, and Reflekron Oy
Selected publications
1. “GaSb diode lasers tunable around 2.6 μm using silicon photonics resonators or external diffractive gratings”: Applied Physics Letters. 116, (2020)
2. “Precise length definition of active GaAs-based optoelectronic devices for low-loss silicon photonics integration”: Optics Letters. 45, (2020)
3. "Power scaling and thermal lensing in 825 nm emitting membrane external-cavity surface-emitting lasers”: Optics Letters. 45, (2020)
4. “High-power single mode GaSb-based 2 μm superluminescent diode with double-pass gain”: Appl. Phys. Lett. 115, (2019)
5. "Epitaxial phases of high Bi content GaSbBi alloys”: Journal of Crystal Growth. 516, (2019)
6. “Photovoltaic properties of low-bandgap (0.7–0.9 eV) lattice-matched GaInNAsSb solar junctions grown by molecular beam epitaxy on GaAs”: Solar Energy Materials and Solar Cells. 195, (2019)
7. “Treatment of telangiectasia on the cheeks with a compact yellow (585 nm) semiconductor laser and a green (532 nm) KTP laser: a randomized double-blinded split-face trial”: Lasers in Surgery and Medicine. 51, (2019)
8. “Lattice‐matched four‐junction tandem solar cell including two dilute nitride bottom junctions”: Progress in PV: Research and Applications, (2018)
9. “Optically pumped VECSELs: review of technology and progress” : Journal of Phys. D: Appl.Phys. 50, (2017)
10. “VECSEL systems for the generation and manipulation of trapped magnesium ions” : Optica 3, (2016)
