Investigation of Nonlinear Optical Properties of Quantum Dots Deposited onto a Sample Glass Using Time-Resolved Inline Digital Holography

Abstract

We report on the application of time-resolved inline digital holography in the study of the nonlinear optical properties of quantum dots deposited onto sample glass. The Fresnel diffraction patterns of the probe pulse due to noncollinear degenerate phase modulation induced by a femtosecond pump pulse were extracted from the set of inline digital holograms and analyzed. The absolute values of the nonlinear refractive index of both the sample glass substrate and the deposited layer of quantum dots were evaluated using the proposed technique. To characterize the inhomogeneous distribution of the samples’ nonlinear optical properties, we proposed plotting an optical nonlinearity map calculated as a local standard deviation of the diffraction pattern intensities induced by noncollinear degenerate phase modulation.

Design for Ultrafast Raster Photography with a Large Amount of Spatio-Temporal Information

“…However, these methods are insufficient for observing transient dynamics on the atomic time scale (1 ps∼10 fs), primarily due to the limitations of mechanical mechanisms and the electronic readout speed of detectors. Fortunately, the generation and development of ultrashort pulse lasers have propelled the temporal resolution of imaging based on pump-probe technology into the attosecond region [9][10][11][12][13], enabling the effective observation of repeated ultrafast events. To capture non-repetitive processes, various single-shot ultrafast imaging techniques have emerged, boasting frame rates of up to a trillion frames per second (Tfps).…”