Promotionsvortrag Physik: „Two-dimensional quantum measurements through multimode optical parametric amplification“

Ankündigung des Promotionsvortrags von: Herrn Ismail Barakat

The experimental realization of spatial multimode optical parametric amplification (MOPA) using a type-I BBO crystal is presented. MOPA introduces a novel approach to measure squeezing in multimode radiation, showing great potential compared to traditional methods. Squeezing, the re-duction of quantum fluctuations below the shot noise limit (SNL), is achieved using optical para-metric amplification (OPA) and further amplified by OPA, enabling the measurement of squeezed/anti-squeezed quadratures occupying multimode space. This method facilitates simul-taneous measurement of squeezing for multiple modes via direct intensity detection with a cam-era. Despite the low flux of photons, squeezing and anti-squeezing were successfully observed for eight modes. Furthermore, the phase sensitivity of the multimode squeezed vacuum was ana-lysed, demonstrating quantum-enhanced accuracy exceeding the SNL in the two-dimensional space. Finally, near-field imaging was employed to overcome the phase correlations of the bipar-tite radiation in the far field, enabling true relative phase measurements with quantum sensitivity beyond the SNL. This approach shows MOPA's potential for quantum-enhanced phase-sensitive measurements in two-dimensional spatial domains.

(Vortrag auf Englisch)

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