SEMINARIUM Z FIZYKI BIOLOGICZNEJ I BIOINFORMATYKI
\nInstytutu Biochemii i Biofizyki PAN, Instytutu Fizyki PAN
\ni Zak\u0142adu Biofizyki UW<\/p>\n
Wednesday, 06.05.2026, 15:15 (3.15 p.m. CET)<\/p>\n
Institute of Physics, Polish Academy of Sciences
\nAl. Lotnik\u00f3w 32\/46, 02-668 Warsaw<\/p>\n
Auditorium (turn left at the reception desk)<\/p>\n
and<\/p>\n
https:\/\/zoom.us\/j\/91976153012?pwd=azNiMWE4UnhPN3lRQlY2UHZHOXVkQT09<\/p>\n
„High dimensional and high resolution NMR methods
\nfor studies of intrinsically disordered proteins”<\/p>\n
Prof. Wiktor Ko\u017ami\u0144ski<\/p>\n
Biological and Chemical Research Centre
\nUniversity of Warsaw<\/p>\n
Bogdan Lesyng (UW)
\nAnna Nied\u017awiecka (IF PAN)
\nPiotr Zielenkiewicz (IBB)<\/p>\n
————————-
\nMeeting ID: 919 7615 3012
\nPasscode: 747922
\nOne tap mobile
\n+48223073488,,91976153012#,,,,*747922# Poland
\n+48223987356,,91976153012#,,,,*747922# Poland<\/p>\n
Dial by your location
\n+48 22 307 3488 Poland
\n+48 22 398 7356 Poland
\n+48 22 306 5342 Poland
\n————————-<\/p>\n
ABSTRACT
\nPhoton avalanche (PA) is a highly nonlinear optical phenomenon first discovered in
\n1979, originally investigated in bulk crystals at cryogenic temperatures for
\nmid-infrared photon detection and upconversion lasers. It is initiated when photon
\nabsorption triggers a cascade of excited-state absorption (ESA) and energy transfer
\nprocesses, forming a positive feedback loop that rapidly amplifies emission. A
\ndefining feature of PA is a sharp excitation power threshold, above which the
\nluminescence intensity increases dramatically. Beyond this threshold, the emission
\nintensity (IE) follows a power-law dependence on excitation power (IP), IE=(IP)^S,
\nwith an exceptionally large nonlinearity index S exceeding 10 and sometimes reaching
\nseveral hundred. The process exhibits efficient anti-Stokes emission and a
\ncharacteristic S-shaped dependence of emission intensity on excitation power density
\n[1].
\nAchieving PA requires stringent conditions, including resonant ESA between excited
\nstates and an ESA cross section much larger than ground-state absorption. Equally
\ncritical is efficient cross-relaxation between lanthanide ions, which multiplies the
\npopulation of intermediate states and sustains the avalanche process. Recent
\ndemonstrations of PA in nano- and micro-scale materials, particularly Tm^3+-doped
\nlow-phonon hosts, have opened new opportunities for ultrasensitive sensing and
\nadvanced photonic technologies.
\nDuring the talk, the basics of PA will be presented, likewise the novel concepts and
\ndemonstrations of superresolution imaging [2,3,4], and ultrasensitize sensing
\n[1,5,6]. Some new directions and challenges will be indicated towards better (lower
\nthreshold, controlled non-linearity) PA nano & micro particles and layers.<\/p>\n
References<\/p>\n
1. M. Szalkowski, A. Kotulska, M. Dudek, Z. Korczak, M. Majak, \u0141. Marciniak, M.
\nMisiak, K. Prorok, A. Skripka, P. J. Schuck, E. M. Chan, A. Bednarkiewicz, et al.,
\nChem. Soc. Rev. 54, 983 (2025).
\n2. Artur Bednarkiewicz, Emory M.-Y. Chan, Agata M. Kotulska, \u0141ukasz Marciniak,
\nKatarzyna Prorok, et al., Nanoscale Horiz. 4, 706 (2019).
\n3. Lee, E. Xu, Y. Liu, A. Teitelboim, K. Yao, A. Fernandez-Bravo, A. Kotulska, S.
\nH. Nam, Y. D. Suh, A. Bednarkiewicz, B. E. Cohen, E. M. Chan, P. J. Schuck, et
\nal., Nature 592, 554 (2021).
\n4. S. Karmegam, M. Szalkowski, M. Misiak, K. Prorok, D. Szyma\u0144ski, A.
\nBednarkiewicz, et al., arXiv:2507.14667 (2025).
\n5. Bednarkiewicz, E. M. Chan, K. Prorok, et al., Nanoscale Adv. 2, 4863 (2020).
\n6. M. Majak, M. Misiak, A. Bednarkiewicz, et al., Mater. Horiz. 11, 4791 (2024).<\/p>\n
Wiadomo\u015b\u0107 1 z 10287<\/p>\n","protected":false},"excerpt":{"rendered":" SEMINARIUM Z FIZYKI BIOLOGICZNEJ I BIOINFORMATYKI Instytutu Biochemii i Biofizyki PAN, Instytutu Fizyki PAN i Zak\u0142adu Biofizyki UW Wednesday, 06.05.2026, 15:15 (3.15 p.m. CET) Institute of Physics, Polish Academy of Sciences Al. Lotnik\u00f3w 32\/46, 02-668 Warsaw Auditorium (turn left at … Czytaj dalej ![\"\"](\"http:\/\/ptbf.pl\/wp-content\/plugins\/thumbnail-for-excerpts\/tfe_no_thumb.png\" "\\"\\"")
<\/a>