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SUMMARY:IEM Distinguished Lecturers Seminar: Ultracompact nonlinear platfo
 rms based on layered semiconductors for phase-matched up- and down-convers
 ion
DTSTART:20241119T131500
DTEND:20241119T140000
DTSTAMP:20260510T132021Z
UID:a7b4c5fd5ce44d1d4dfee13ca9afe6308a5740fbba03514f5a13bc29
CATEGORIES:Conferences - Seminars
DESCRIPTION:Chiara Trovatello\, PhD\, Department of Mechanical Engineering
 \, Columbia University\, USA\n & Department of Physics\, Politecnico di M
 ilano\, Italy\n***Coffee and cookies will be served at 13:00 in the hall o
 f BM 5202***\n\nAbstract\nNonlinear optics lies at the heart of classical 
 and quantum light generation. The miniaturization and on-chip integration 
 paradigm\, which has dominated the world of electronics\, is now shifting 
 to the field of photonics\, with the development of all-optical integrated
  circuits\, essential for new photonic technologies required to address ri
 sing demands for fast and energy-efficient quantum processing. The miniatu
 rization problem manifests as a stubborn trade-off between frequency conve
 rsion efficiency and size.\n\nWhile 2D materials\, such as transition meta
 l dichalcogenides (TMDs)\, hold great promise thanks to their large nonlin
 earity (χ(2))\, their stability in ambient conditions\, their flexibility
  and mechanical strength\, and easy system integration\, monolayer-thick s
 heets provide low overall conversion efficiency (~10-10) due to near-infin
 itesimal path lengths.\n\nHere we realize periodically poled transition me
 tal dichalcogenides (PPTMDs)\, using 3R-MoS2. Due to its large nonlinearit
 y\, we achieve macroscopic frequency conversion efficiency (0.01%-0.1%) ov
 er a microscopic thickness of only 3μm (just three poling periods)\, i.e.
 \, 108 times more efficient than a monolayer TMD. Further\, we report the 
 generation of entangled photon pairs at telecom wavelengths via quasi-phas
 e-matched spontaneous parametric down-conversion (SPDC) at the key 1550 nm
  telecom wavelength\, reaching a maximum coincidence-to-accidental-ratio (
 CAR) of 638 ± 75\, thus outperforming any existing van der Waals-based SP
 DC source by nearly 2 orders of magnitude.\n\nThis research opens the new 
 and unexplored field of phase-matched nonlinear optics with microscopic va
 n der Waals crystals. As on-chip integrable\, programmable\, microscopic\,
  entangled photon sources\, PPTMDs finally unlock new applications that re
 quire simple\, ultracompact technologies for integrated quantum circuitry 
 and sensing.\n\nBio\nChiara Trovatello is a Marie Skłodowska-Curie Global
  Fellow at Columbia University and Politecnico di Milano. Her research act
 ivity focuses on ultrafast spectroscopy\, nonlinear optics and quantum
  optics of low-dimensional materials\, e.g.\, 2D semiconductors. She has p
 ublished >25 papers\, has delivered >30 invited and contributed talks at l
 eading conferences and institutions\, and has been part of the organizing 
 committee of international conferences\, e.g.\, MRS\, CLEO. \nAmong her p
 rizes and grants\, she has been awarded the Marie Skłodowska-Curie RISE 
 Fellowship (2019)\, the Marie Skłodowska-Curie Global Fellowship (2022)\
 , the 2022 Bernard J. Couillaud Prize\, the 2023 Young Investigator Bruno 
 Touschek Award\, the 2024 L’Oréal-UNESCO for Women in Science Prize\, 
 the 2024 Blavatnik Regional Finalist Award and the 2024 Optica Foundation 
 Challenge Award.\nChiara Trovatello was the founder and the former preside
 nt of the Optica Chapter of Milan and in 2024 she has been awarded the lif
 etime title of Optica Ambassador. Beyond research\, she passionately advoc
 ates for open science\, ethical research\, equal representation and opport
 unities in STEM.
LOCATION:BM 5202 https://plan.epfl.ch/?room==BM%205202 https://epfl.zoom.u
 s/j/67449285011
STATUS:CONFIRMED
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