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DTSTAMP:20260423T182656Z
SUMMARY:Complexity Seminar: Spatio-Temporal Complexity in Semiconductor Las
 ers
DESCRIPTION:A Centre for Complexity Science Seminar  by Ortwin Hess.\nA lo
 ng-standing challenge for large-area semiconductor lasers is taming the in
 herent and notoriously complex (frequently chaotic) spatio-temporal dynami
 cs in edge-emitting  [1] and vertical-cavity surface emitting  [2] semic
 onductor lasers [3]. General wisdom and most strategies proposed and techn
 ologically applied to date all seek to reduce the level of complexity by r
 educing the number of lasing modes\, for example by optical injection\, de
 layed  [4] or delayed structured and filtered optical feedback  [5] or\,
  more recently\, through super-symmetry in semiconductor laser arrays  [6
 ]. Based on a radically different strategy involving fighting laser chaos 
 with quantum-chaotic or nano-disordered cavities we have recently shown th
 at near-field and quantum chaos on the nanoscale leads to disorder which d
 isrupts the formation of self-organized structures such as filaments that 
 would normally lead to instabilities [7].\nThe talk will give an overview 
 of the foundations and development of theoretical approaches and experimen
 ts to simulate and understand the complex spatio-temporal near-field and q
 uantum dynamics of large-area semiconductor lasers. We will outline how mi
 croscopic and dynamic materials-based simulations are the basis for an int
 erpretation of the complex dynamics  [3]. We will discuss the recently in
 troduced strategy of using quantum-chaotic or nano-disordered cavities suc
 h that near-field and quantum chaos on the nanoscale leads to disorder whi
 ch disrupts the formation of self-organized structures such as filaments t
 hat would normally lead to instabilities [7]. Based on these principles we
  will further present an innovative approach for ultrafast parallel quantu
 m noise ‘harvesting’ by spatio-temporal many-mode and quantum chaotic 
 lasing dynamics in semiconductor lasers forming the basis for a new paradi
 gm for greatly accelerated quantum random bit generation [8].\nReferences\
 n[1]            I. Fischer\, O. Hess\, W. Elsäßer\, and E. G
 öbel\, Complex Spatio-Temporal Dynamics in the near-Field of a Broad-Area
  Semiconductor Laser\, EPL 35\, 579 (1996).\n[2]            O. 
 Hess\, Spatio-Spectral Dynamics and Spontaneous Ultrafast Optical Switchin
 g in VCSEL Arrays\, Opt. Express\, OE 2\, 424 (1998).\n[3]        
     E. Gehrig and O. Hess\, Spatio-Temporal Dynamics and Quantum Fluct
 uations in Semiconductor Lasers (Springer Science & Business Media\, 2003)
 .\n[4]            C. Simmendinger\, D. Preißr\, and O. Hess\, 
 Stabilization of Chaotic Spatiotemporal Filamentation in Large Broad Area 
 Lasers by Spatially Structured Optical Feedback\, Opt. Express\, OE 5\, 48
  (1999).\n[5]            N. Gaciu\, E. Gehrig\, and O. Hess\, C
 ontrol of Broad-Area Laser Dynamics with Delayed Optical Feedback\, in Han
 dbook of Chaos Control (John Wiley & Sons\, Ltd\, 2008)\, pp. 427–453.\n
 [6]            M. P. Hokmabadi\, N. S. Nye\, R. El-Ganainy\, D.
  N. Christodoulides\, and M. Khajavikhan\, Supersymmetric Laser Arrays\, S
 cience 363\, 623 (2019).\n[7]            S. Bittner\, S. Guazzo
 tti\, Y. Zeng\, X. Hu\, H. Yılmaz\, K. Kim\, S. S. Oh\, Q. J. Wang\, O. H
 ess\, and H. Cao\, Suppressing Spatiotemporal Lasing Instabilities with Wa
 ve-Chaotic Microcavities\, Science 361\, 1225 (2018).\n[8]        
     K. Kim\, S. Bittner\, Y. Zeng\, S. Guazzotti\, O. Hess\, Q. J. Wan
 g\, and H. Cao\, Massively Parallel Ultrafast Random Bit Generation with a
  Chip-Scale Laser\, Science 371\, 948 (2021).\n 
URL:https://www.imperial.ac.uk/events/143224/complexity-seminar-spatio-temp
 oral-complexity-in-semiconductor-lasers/
DTSTART;TZID=Europe/London:20220111T120000
DTEND;TZID=Europe/London:20220111T130000
LOCATION:United Kingdom
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