Polarization dependence of semiconductor exciton and biexciton contributions to phase-resolved optical two-dimensional Fourier-transform spectra

We study the coherent light-matter interactions of GaAs quantum wells associated with excitons, biexcitons and many-body effects. For most polarization configurations, excitonic features dominate the phase-resolved two-dimensional Fourier-transform (2DFT) spectra and have dispersive lineshapes, indicating the presence of many-body interactions. For cross-linear excitation, excitonic features become weak and absorptive due to the strong suppression of many-body effects; a result that can not be directly determined in transient four-wave mixing experiments. The biexcitonic features do not weaken for cross-polarized excitation and thus are more important.Comment: 4 page, 3 figures, journal article - rapid communicatio

All-optical retrieval of the global phase for two-dimensional Fourier-transform spectroscopy

A combination of spatial interference patterns and spectral interferometry are used to find the global phase for non-collinear two-dimensional Fourier-transform (2DFT) spectra. Results are compared with those using the spectrally resolved transient absorption (STRA) method to find the global phase when excitation is with co-linear polarization. Additionally cross-linear polarized 2DFT spectra are correctly phased using the all-optical technique, where the SRTA is not applicable.Comment: 6 pages, 7 figures, journal publicatio

Coherent two-dimensional Fourier transform spectroscopy using a 25 Tesla resistive magnet.

We performed nonlinear optical two-dimensional Fourier transform spectroscopy measurements using an optical resistive high-field magnet on GaAs quantum wells. Magnetic fields up to 25 T can be achieved using the split helix resistive magnet. Two-dimensional spectroscopy measurements based on the coherent four-wave mixing signal require phase stability. Therefore, these measurements are difficult to perform in environments prone to mechanical vibrations. Large resistive magnets use extensive quantities of cooling water, which causes mechanical vibrations, making two-dimensional Fourier transform spectroscopy very challenging. Here, we report on the strategies we used to overcome these challenges and maintain the required phase-stability throughout the measurement. A self-contained portable platform was used to set up the experiments within the time frame provided by a user facility. Furthermore, this platform was floated above the optical table in order to isolate it from vibrations originating from the resistive magnet. Finally, we present two-dimensional Fourier transform spectra obtained from GaAs quantum wells at magnetic fields up to 25 T and demonstrate the utility of this technique in providing important details, which are obscured in one dimensional spectroscopy

Atomic clock using a photodetector

In one embodiment, an atomic clock for use in an electronic device includes a photodetector with a single-isotope silicon crystal doped with impurity atoms in which a photocurrent generated via a two-photon process within the photodetector is used as a frequency resonance of the atomic clock

Atomic clock using a photodetector

In one embodiment, an atomic clock for use in an electronic device includes a photodetector with a single-isotope silicon crystal doped with impurity atoms in which a photocurrent generated via a two-photon process within the photodetector is used as a frequency resonance of the atomic clock

Silicon-based atomic clocks

In one embodiment, a silicon-based atomic clock for use in an electronic device includes a single-isotope silicon crystal and energy level transitions within the silicon are used as a frequency resonance of the clock

Photoluminescence and Raman Enhancement by Edge Plasmons in MnPS₃

Unconventional plasmonic materials beyond traditional noble metals extend applications of nanotechnology to novel optical, electrical, and magnetic devices. For example, the low photoluminescence (PL) efficiency of two-dimensional (2D) magnetic materials hinders their effective utilization in magnetooptical studies and practical applications, despite their significant role in information storage and spintronic devices. Plasmon-enhanced PL is a promising route toward efficient magneto-optical applications. Here, we report the first observations of enhanced PL and Raman signals in a multilayered 2D antiferromagnet MnPS3, which are attributed to the near-field edge plasmon antenna enhancement in few hundred nm thick flakes. We observed two in-gap near-infrared emission signals and studied their thickness dependence. For the first time, we performed tip-enhanced photoluminescence (TEPL) imaging of MnPS3 in classical (tapping mode) and quantum plasmonic (contact mode) regimes. Classical TEPL showed signal enhancement via plasmonic gap-mode and surface guided waves. Quantum plasmonic TEPL showed evidence for edge plasmons in MnPS3 via tunneling-induced PL suppression, revealing a 300 nm wide edge plasmon size. Our work opens new possibilities for plasmonic applications of MnPS3, while quantum plasmonic imaging may be used to discover novel plasmonic materials

Coherent Two-dimensional Fourier Transform Spectroscopy using a 25 Tesla Resistive Magnet

We performed nonlinear optical two-dimensional Fourier transform spectroscopy measurements using an optical resistive high-field magnet on GaAs quantum wells. Magnetic fields up to 25 T can be achieved using the split helix resistive magnet. Two-dimensional spectroscopy measurements based on the coherent four-wave mixing signal require phase stability. Therefore, these measurements are difficult to perform in environments prone to mechanical vibrations. Large resistive magnets use extensive quantities of cooling water, which causes mechanical vibrations, making two-dimensional Fourier transform spectroscopy very challenging. Here, we report on the strategies we used to overcome these challenges and maintain the required phase-stability throughout the measurement. A self-contained portable platform was used to set up the experiments within the time frame provided by a user facility. Furthermore, this platform was floated above the optical table in order to isolate it from vibrations originating from the resistive magnet. Finally, we present two-dimensional Fourier transform spectra obtained from GaAs quantum wells at magnetic fields up to 25 T and demonstrate the utility of this technique in providing important details, which are obscured in one dimensional spectroscopy