Research at ORC

ORC’s research activities can be divided into two main research areas and five research topics. Click on the topics in the image below or scroll down for details.

The nanotechnology research area includes a comprehensive chain of activities starting from synthesis of semiconductor heterostructures by molecular beam epitaxy (MBE), structural investigations of semiconductor materials and studies of surfaces and interfaces. It also covers processing of optoelectronics devices and nanolithography, as well as specific activities for device characterization.

The ultrafast and intense optics research area encompasses lasers and other novel optical devices based not only on semiconductor components such as saturable absorbing mirrors and disk lasers, but also specialty active optical fibers. Moreover, the area includes basic research in the field of few-cycle pulsed lasers and carrier-envelope phase synchronization.

Surface Science Laboratory joined ORC in 2011 reflecting our long-term vision for enhancing multidisciplinary research. There is extensive internal collaboration between the different groups at ORC; this is one of our strengths.

>> Browse our project list
>> Read our publications
>> See our services for business

Research groups

We have five closely collaborating research groups, described below.

• Semiconductor technology group
• Ultrafast and intense optics group
• Surface science laboratory
• Nanophotonics group
• Few cycle optics group

Semiconductor technology group

Mircea Guina Professor

The semiconductor technology group is lead by Prof. Mircea Guina. With six senior researchers, 12 PhD students, and several undergraduate students and technical support personnel, it is the largest research team at ORC.

The group conducts a comprehensive chain of research activities targeting synthesis of novel III-V semiconductor materials, development of advanced nanotechnology tools for the fabrication of optoelectronics devices, and the development of application tailored optoelectronics components. Using five Molecular Beam Epitaxy (MBE) reactors we can fabricate a wide range of material compounds based on GaAs, InP and GaSb. We pool our efforts to maintain a leading position in MBE by developing new techniques enabling breakthroughs in fabrication of compound semiconductor nanostructures (for example: Appl. Phys. Lett. 97, 173107, 2010). We have two fully equipped clean rooms dedicated to processing and packaging of specialized laser diodes and solar cells.

The main research areas of the semiconductor group are:

• Epitaxy of dilute nitride (InGaAsNSb) compounds
• Site-controlled epitaxy of quantum dots
• Epitaxy of GaSb heterostructures for 2–3 µm wavelength range
• Application of nanoimprint lithography (NIL) for processing optoelectronic devices
• Development of ultrafast laser diodes for telecommunication
• Development of high-power narrow-linewidth eye-safe laser diodes for LIDAR
• Development of high power semiconductor disk lasers (SDLs) for spectroscopic applications (589 nm, 650 nm, 1120 nm, 1156 nm, 2 µm, 2.3 µm)
• Development of high-efficiency solar cells for concentrated photovoltaic systems (CPV)

Many of our activities are carried out within the framework of European Commission FP7 consortia, COST networks, and other bilateral collaborations with industry and high profile research groups in Europe, USA and China.

>> Find out more about our semiconductor research

Ultrafast and intense optics group

Oleg Okhotnikov Professor

The Ultrafast and Intense Optics (UIO) group is lead by Prof. Oleg Okhotnikov and has nine researchers.

The group focuses its research on ultrafast optical phenomena, nonlinear optics, semiconductor disk lasers, and fibre devices for rapidly developing applications, including materials processing, medicine, biology, display technology, and optical communications. This work is best described as interplay between fibre optics and semiconductor physics.

The group is equipped with a broad selection of top-notch optical and optoelectronic devices and instruments, including commercial and in-house-built ultrafast and tunable laser sources, as well as state-of-the-art processing and characterization equipment. The research activities are backed up by worldwide collaboration with academic and industrial partners.

The main research topics are

• Ultrashort pulse generation and manipulation based on MBE-grown semiconductor saturable absorber mirrors (SESAMs)
• Dispersion compensation with semiconductors and photonic crystal structures
• Nonlinear optics research, including supercontinuum generation and Raman amplification
• Wavelength and power scaling of semiconductor disk lasers
• High-power CW and pulsed fibre lasers and amplifiers for materials processing and LIDAR applications based on tapered active fibre technology
• Optical fibre technology, passive optical fibre components
• Thin film coatings by e-beam evaporation

>> Find out more about our ultrafast and intense optics research

Surface science laboratory

Mika Valden Professor

Surface science research is lead by Prof. Mika Valden. The group has 12 researchers.

The surface science group conducts research on the phenomena at surfaces and interfaces of nanostructured metal and semiconductor materials. The main objectives are to gain insights into the interdependence between the physicochemical properties of the surface and the environment at molecular level and to develop novel materials by functionalizing surfaces on the nanometer scale.

Surface science laboratory operates within FIMECC Ltd. – Finnish Metals and Engineering Competence Cluster – and its Demanding Applications (DEMAPP) program. FIMECC Ltd. is the strategic centre for science, technology, and innovation (SHOK) in metal products and mechanical engineering industries in Finland.

In addition, surface science laboratory has a strong background in the research of surface-mediated processes in heterogeneous catalysis and on copper based alloys. We also carry out contract research on various industrial materials.

Recent research topics include:

• Nanostructured materials and nanoscience
• Dynamics and kinetics of elementary surface processes
• Surface-mediated processes on metal alloys
• Surface biofunctionalization of metallic materials
• Functionality in surface coatings
• Surface science approach to heterogeneous catalysis
• Opto- and microelectronics materials
• Novel surface analytical instruments and systems

Experimentally, the group relies on various surface sensitive methods operating in ultrahigh vacuum. The main research equipment includes electron spectroscopy, scanning tunneling microscopy, molecular beam surface scattering, low energy electron diffraction, and thermal desorption spectroscopy. The facilities are equiped with various sample preparation and surface modification methods enabling sample treatments in situ in UHV. In addition, we have access to advanced synchrotron radiation-based research facilities at MAX IV Laboratory: e.g. high-resolution photoelectron spectroscopy and X-ray absorption spectroscopy.

>> Find out more about our surface science research

Nanophotonics group

Tapio Niemi Professor

Nanophotonics research is lead by Prof. Tapio Niemi. The group consist of one senior researcher and four doctoral students.

The nanophotonics group conducts research on plasmonics, metamaterials, resonant nanostructures and pulsed-laser deposition of nanoparticles.

Experimentally, the group relies on UV-nanoimprint lithography, pulsed laser ablation and various standard nanofabrication and characterization techniques. It also collaborates closely with the semiconductor group for quantum well and dot samples. Most recently, the group developed a Raman spectroscopy setup. The group also has simulation capabilites for nanophotonic structures, using a combination of commercial (Comsol Multiphysics) and self-made software.

Recent research topics include the following:

• The fabrication of metallic nanocones by nanoimprint lithography and their linear and nonlinear optical properties [Nano Lett. 2012]
• Second harmonic generation with silicon nitride films [Appl. Phys. Lett. 2012]
• Single-step fabrication of gold/silicon core/shell-nanoparticles by pulsed laser ablation in liquids [Phys. Chem. Chem. Phys. 2012]
• Broadband infrared mirrors using guided-mode resonance in a subwavelength germanium grating [Opt. Lett. 2010]
• Improving the emission efficiency of periodic plasmonic structures for lasing applications [Opt. Comm. 2011]

>> Find out more about our nanophotonics research

Few cycle optics group

Gunter Steinmeyer Professor

The Few Cycle Optics group (FCO) is headed by Finland Distinguished Professor (FiDiPro) Günter Steinmeyer. Other group members are postdoctoral researcher Dr. Lasse Orsila and research assistant Janne Hyyti.

FCO is pursuing a new avenue for the generation of phase-stable and intense femtosecond pulses. The laboratory, established in late 2008, is developing a pulse generation scheme consisting of a phase-stabilized amplified laser system with a subsequent pulse compression stage. The amplifier is seeded by a short-pulse oscillator that delivers 2.5-cycle pulses with nJ energy, which is then amplified to several microjoules of energy at reduced repetition rates of 100 kHz.

During its first few years the laboratory has managed to collect a good selection of state-of-the art optoelectronic equipment, including a commercial nearly octave spanning sub 7-fs Ti:sapphire laser oscillator,a self-made phase stabilization system, a custom-made cryogenic cooling chamber for amplifier, RF systems for signal analysis, timing and delay generators and a femtosecond autocorrelator. The group is well connected within the femtosecond science community and close collaboration with carrier-envelope phase stabilization is ongoing with Max-Born Institute, Berlin, Germany.

>> Find out more about our few cycle optics research