Time-resolved Spectroscopy

The heart of the setup for the time-resolved spectroscopy is composed of two Ti:Sapphire oscillators (Coherent Mira-HP-Duo) pumped by a high stability Nd:YVO4 DPSS CW laser with an output power of 18 W (Coherent Verdi-V18) . Both lasers provide a high peak power, ultra short pulses with the time duration of ~140 fs or ~1.5 ps in the wavelength range of 700 - 1080 nm with a repetition rate of 76 MHz. For more sophisticated experiments both oscillators can be synchronized to provide pulse trains with well defined time relation and minimal jitter.

The application of two Optical Parametric Oscillators (OPOs) based on periodically poled nonlinear crystals with high conversion efficiency (Coherent/APE OPO-HP VIS/IR) broadens the accessible spectral range from 505 nm up to 3.7 µm also due to the intracavity second harmonic generation. OPOs are capable of providing femto- or picosecond pulses at 1.3 µm and 1.55 µm with an average power of 1.5 W .

Second and third harmonic generation modules (APE Harmonix and custom design setups) add accessible spectral ranges of 360500 nm and 266 nm330 nm .

The detection system for photoluminescence decay time experiments consists of two Hamamatsu Streak Cameras each coupled to the Acton SP2360 monochromator . It enables to measure photoluminescence dynamics in a broad spectral range from 250 up to 1600 nm and time range between 200 ps1 ms with a temporal resolution better then 15 ps . Measurement in the liquid helium temperature as well as magnetic field up to 5 T is also available.

The pump–probe time resolved reflectivity/transmittance is realized thanks to two high resolution mechanical delay line stages. These experiments can be performed with the time resolution restricted to the laser pulse width in the broad detection wavelength range ( 3001700 nm and even deeper into IR). The lock–in based signal measurement technique provides S/N ratio on an excellent level.Current research is concentrated mainly on various semiconductor materials (III-V, III-N-V, II-VI) and their low dimensional structures like quantum dots, quantum dashes and quantum wells. However, other material systems are also the subject of interest (sol-gel materials, organic single-crystal semiconductors, materials doped by rare earth). The main goal is to describe the intra- and interband relaxation channels and incorporated mechanisms, radiative and non-radiative recombination rates, carrier diffusion and tunneling times in various experimental conditions (optical excitation power, temperature, excitation wavelength).

Representative papers

Room Temperature Carrier Kinetics in the W-type GaInAsSb/InAs/AlSb Quantum Well Structure Emitting in Mid-Infrared Spectral Range
M. Syperek, K. Ryczko, M. Dallner, M. Dyksik, M. Motyka, M. Kamp, S. Höfling,c, J. Misiewicz and G. Sęk
Proceedings of the 45th International School and Conference on the Physics of Semiconductors “Jaszowiec” 2016, Szczyrk
Exciton spin relaxation in InAs/InGaAlAs/InP(001) quantum dashes emitting near 1.55μm
M. Syperek, Ł. Dusanowski, M. Gawełczyk, G. Sk, A. Somers, J. P. Reithmaier, S. Höfling, and J. Misiewicz
Applied Physics Letters 109, 193108 (2016)
Ghost Branch Photoluminescence From a Polariton Fluid Under Nonresonant Excitation
M. Pieczarka, M. Syperek, Ł. Dusanowski
PHYSICAL REVIEW LETTERS, Volume: 115, Issue: 18, Article Number: 186401, Published: OCT 26 2015
Single photon emission up to liquid nitrogen temperature from charged excitons confined in GaAs-based epitaxial nanostructures
Ł. Dusanowski, M. Syperek, A. Marynski
APPLIED PHYSICS LETTERS, Volume: 106, Issue: 23, Article Number: 233107, Published: JUN 8 2015
Time-resolved photoluminescence studies of annealed 1.3-μm GaInNAsSb quantum wells
M. Baranowski, R. Kudrawiec, M. Syperek
NANOSCALE RESEARCH LETTERS, Volume: 9, Article Number: 81, Published: FEB 17 2014
Influence of quantum well inhomogeneities on absorption, spontaneous emission, photoluminescence decay time, and lasing in polar InGaN quantum wells emitting in the blue-green spectral region
M. Gładysiewicz, R. Kudrawiec, M. Syperek
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, Volume: 115, Issue: 3, Pages: 1015-1023, Published: JUN 2014
Exciton and biexciton dynamics in single self-assembled InAs/InGaAlAs/InP quantum dash emitting near 1.55 μm
Ł. Dusanowski, M. Syperek, W. Rudno-Rudzinski
APPLIED PHYSICS LETTERS, Volume: 103, Issue: 25, Article Number: 253113, Published: DEC 16 2013