22 research outputs found
Diagonal Slice Four-Wave Mixing: Natural Separation of Coherent Broadening Mechanisms
We present an ultrafast coherent spectroscopy data acquisition scheme that
samples slices of the time domain used in multidimensional coherent
spectroscopy to achieve faster data collection than full spectra. We derive
analytical expressions for resonance lineshapes using this technique that
completely separate homogeneous and inhomogeneous broadening contributions into
separate projected lineshapes for arbitrary inhomogeneous broadening. These
lineshape expressions are also valid for slices taken from full
multidimensional spectra and allow direct measurement of the parameters
contributing to the lineshapes in those spectra as well as our own
Coherent Excitonic Coupling in an Asymmetric Double InGaAs Quantum Well Arises from Many-Body Effects
We study an asymmetric double InGaAs quantum well using optical
two-dimensional coherent spectroscopy. The collection of zero-quantum,
one-quantum, and two-quantum two-dimensional spectra provides a unique and
comprehensive picture of the double well coherent optical response. Coherent
and incoherent contributions to the coupling between the two quantum well
excitons are clearly separated. An excellent agreement with density matrix
calculations reveals that coherent interwell coupling originates from many-body
interactions
Direct imaging of surface plasmon polariton dispersion in gold and silver thin films
We image the dispersion of surface plasmon polaritons in gold and silver thin films of 30 and 50 nm thickness, using angle-resolved white light spectroscopy in the Kretschmann geometry. Calibrated dispersion curves are obtained over a wavelength range spanning from 550 to 900 nm. We obtain good qualitative agreement with calculated dispersion curves that take into account the thickness of the thin film
The Excitation Ladder of Cavity Polaritons
Multidimensional coherent spectroscopy directly unravels multiply excited
states that overlap in a linear spectrum. We report multidimensional coherent
optical photocurrent spectroscopy in a semiconductor polariton diode and
explore the excitation ladder of cavity polaritons. We measure doubly and
triply avoided crossings for pairs and triplets of exciton-polaritons,
demonstrating the strong coupling between light and dressed doublet and triplet
semiconductor excitations. These results demonstrate that multiply excited
excitonic states strongly coupled to a microcavity can be described as two
coupled quantum-anharmonic ladders
Excitation Ladder of Cavity Polaritons
Multidimensional coherent spectroscopy directly unravels multiply excited states that overlap in a linear spectrum. We report multidimensional coherent optical photocurrent spectroscopy in a semiconductor polariton diode and explore the excitation ladder of cavity polaritons. We measure doubly and triply avoided crossings for pairs and triplets of exciton polaritons, demonstrating the strong coupling between light and dressed doublet and triplet semiconductor excitations. These results demonstrate that multiply excited excitonic states strongly coupled to a microcavity can be described as two coupled quantum-anharmonic ladders
Hidden Silicon-Vacancy Centers in Diamond
We characterize a high-density sample of negatively charged silicon-vacancy
(SiV) centers in diamond using collinear optical multidimensional coherent
spectroscopy. By comparing the results of complementary signal detection
schemes, we identify a hidden population of \ce{SiV^-} centers that is not
typically observed in photoluminescence, and which exhibits significant
spectral inhomogeneity and extended electronic times. The phenomenon is
likely caused by strain, indicating a potential mechanism for controlling
electric coherence in color-center-based quantum devices
Demonstration of sub-3 ps temporal resolution with a superconducting nanowire single-photon detector
Improvements in temporal resolution of single-photon detectors enable increased data rates and transmission distances for both classical and quantum optical communication systems, higher spatial resolution in laser ranging, and observation of shorter-lived fluorophores in biomedical imaging. In recent years, superconducting nanowire single-photon detectors (SNSPDs) have emerged as the most efficient time-resolving single-photon-counting detectors available in the near-infrared, but understanding of the fundamental limits of timing resolution in these devices has been limited due to a lack of investigations into the timescales involved in the detection process. We introduce an experimental technique to probe the detection latency in SNSPDs and show that the key to achieving low timing jitter is the use of materials with low latency. By using a specialized niobium nitride SNSPD we demonstrate that the system temporal resolution can be as good as 2.6 ± 0.2 ps for visible wavelengths and 4.3 ± 0.2 ps at 1,550 nm