Epitaxial Nanostructures for Infrared Photonics
Head
Grzegorz Sęk
office: 233, A-1
phone: +48 71 320 45 73
Wojciech Rudno-Rudziński
office: 259, A-1
phone: +48 71 320 29 86
Paweł Podemski
office: 259, A-1
phone: +48 71 320 29 86
Krzysztof Ryczko
office: 319, A-1
phone: +48 71 320 23 29
Agata Kotulska
office: 438, A-1
phone: +48 71 320 33 64
Anna Musiał
office: 231b, A-1
phone: +48 71 320 30 02
Paweł Wyborski (on leave)
office: 440, A-1
phone: +48 71 320 38 19
PhD Students
Tomasz Gzyl
office: 37/6, A-1
Anna Penkała
office: 37/6, A-1
Maja Wasiluk
office: 440, A-1
phone: +48 71 320 38 19
Bartosz Kamiński
Bartosz Kosiński
Paulina Szott
Research
The research concentrates on application of complementary techniques of optical spectroscopy for investigations of epitaxial nanostructures, mostly quantum dots (QD), dedicated for optoelectronic devices operating in the near infrared spectral range, with a strong focus on telecom windows. The studies concern both ensembles of quantum dots, with application prospects as active material for telecom lasers or optical amplifiers, and single quantum emitters, investigated as potential sources of single photons and entangled photons for quantum communication, taking advantage of existing fibre-optical infrastructure.
Photoreflectance (PR) spectroscopy, a variant of a modulation absorption-like technique, is used for determination of the hierarchy of confined states, photoluminescence (PL) gives insight into the optical quality of structures and their emission properties, photoluminescence excitation (PLE) spectroscopy allows investigating carrier transfer processes. Beside experiments on ensembles of dots, the group carries out also PL and PLE measurements on single emitters, also in an external magnetic field. After initial analysis of a power- and polarization-dependence of emission lines from nanoobjects, suitable candidates undergo more sophisticated investigations by means of correlation spectroscopy in Hanbury-Brown and Twiss mode in order to determine emission statistics, in particular to study non-classical character of emission. In the case of multiphoton cascades, potential quantum entanglement is evaluated. Experimental results are supported by 8‑band k∙p calculations for realistic geometries of emitters.