Near-infrared near-field photoluminescence imaging spectroscopy of exciton localized states in GaInNAs/GaAs quantum wells due to nonuniform distribution of nitrogen

The paper reviews our recent achievements in developing a multimode scanning near-field optical microscopy (SNOM) technique. The multimode SNOM apparatus allows us to simultaneously measure spatial variations of photoluminescence spectra in the illumination and illumination-collection modes, their transients and sample surface morphology. The potential of this technique has been demonstrated on a polar InGaN epitaxial layer and nonpolar InGaN/GaN quantum wells. SNOM measurements have allowed revealing a number of phenomena, such as the band potential fluctuations and their correlation to the surface morphology, spatial nonuniformity of the radiative and nonradiative lifetimes, as well as the extended band nature of localized states. The combination of different modes enabled measurements of the ambipolar carrier diffusion and its anisotropy.

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Single-shot imaging of surface molecular ionization in nanosystems

Nanophotonics ◽

10.1515/nanoph-2021-0172 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Fenghao Sun ◽

Hui Li ◽

Shanshan Song ◽

Fei Chen ◽

Jiawei Wang ◽

...

Keyword(s):

Near Infrared ◽

Strong Field ◽

Imaging Technique ◽

Near Field ◽

Velocity Map Imaging ◽

Single Shot ◽

Surface Molecules ◽

Nanoparticle Interactions ◽

Field Response ◽

Ion Species

Abstract Using single-shot velocity map imaging technique, explosion imaging of different ion species ejected from 50 nm SiO2 nanoparticles are obtained excitedly by strong near-infrared and ultraviolet femtosecond laser fields. Characteristic momentum distributions showing forward emission of the ions at low excitation intensities and shock wave behaviors at high intensities are observed. When the excitation intensity is close to the dissociative ionization threshold of the surface molecules, the resulting ion products can be used to image the instant near-field distributions. The underlying dynamics of shock formation are simulated by using a Coulomb explosion model. Our results allow one to distinguish the ultrafast strong-field response of various molecular species in nanosystems and will open a new way for further exploration of the underlying dynamics of laser-and-nanoparticle interactions.

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The Improvement on the Performance of DMD Hadamard Transform Near-Infrared Spectrometer by Double Filter Strategy and a New Hadamard Mask

Micromachines ◽

10.3390/mi10020149 ◽

2019 ◽

Vol 10 (2) ◽

pp. 149 ◽

Cited By ~ 1

Author(s):

Zifeng Lu ◽

Jinghang Zhang ◽

Hua Liu ◽

Jialin Xu ◽

Jinhuan Li

Keyword(s):

Near Infrared ◽

Signal To Noise Ratio ◽

Nonuniform Distribution ◽

Stray Light ◽

Spectral Energy ◽

Hadamard Transform ◽

Digital Micromirror Device ◽

Infrared Spectrometer ◽

Near Infrared Spectrometer ◽

The Impact

In the Hadamard transform (HT) near-infrared (NIR) spectrometer, there are defects that can create a nonuniform distribution of spectral energy, significantly influencing the absorbance of the whole spectrum, generating stray light, and making the signal-to-noise ratio (SNR) of the spectrum inconsistent. To address this issue and improve the performance of the digital micromirror device (DMD) Hadamard transform near-infrared spectrometer, a split waveband scan mode is proposed to mitigate the impact of the stray light, and a new Hadamard mask of variable-width stripes is put forward to improve the SNR of the spectrometer. The results of the simulations and experiments indicate that by the new scan mode and Hadamard mask, the influence of stray light is restrained and reduced. In addition, the SNR of the spectrometer also is increased.

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Optical properties of extended and localized states in m-plane InGaN quantum wells

Applied Physics Letters ◽

10.1063/1.4794904 ◽

2013 ◽

Vol 102 (10) ◽

pp. 101102 ◽

Cited By ~ 30

Author(s):

S. Marcinkevičius ◽

K. M. Kelchner ◽

S. Nakamura ◽

S. P. DenBaars ◽

J. S. Speck

Keyword(s):

Optical Properties ◽

Quantum Wells ◽

Localized States ◽

Ingan Quantum Wells

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Anisotropic excitation of surface plasmon polaritons on a metal film by a scattering-type scanning near-field microscope with a non-rotationally-symmetric probe tip

Nanophotonics ◽

10.1515/nanoph-2017-0042 ◽

2018 ◽

Vol 7 (1) ◽

pp. 269-276 ◽

Cited By ~ 7

Author(s):

Frederik Walla ◽

Matthias M. Wiecha ◽

Nicolas Mecklenbeck ◽

Sabri Beldi ◽

Fritz Keilmann ◽

...

Keyword(s):

Surface Plasmon ◽

Surface Plasmon Polaritons ◽

Metal Film ◽

Near Infrared ◽

Near Field ◽

Optical Microscope ◽

Anisotropic Surface ◽

Surface Wave Propagation ◽

Rotationally Symmetric ◽

Plasmon Polaritons

AbstractWe investigated the excitation of surface plasmon polaritons on gold films with the metallized probe tip of a scattering-type scanning near-field optical microscope (s-SNOM). The emission of the polaritons from the tip, illuminated by near-infrared laser radiation, was found to be anisotropic and not circularly symmetric as expected on the basis of literature data. We furthermore identified an additional excitation channel via light that was reflected off the tip and excited the plasmon polaritons at the edge of the metal film. Our results, while obtained for a non-rotationally-symmetric type of probe tip and thus specific for this situation, indicate that when an s-SNOM is employed for the investigation of plasmonic structures, the unintentional excitation of surface waves and anisotropic surface wave propagation must be considered in order to correctly interpret the signatures of plasmon polariton generation and propagation.

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Strong near-infrared photoluminescence and absorption from Si/Si1−xGex type-II multiple quantum wells on bulk crystal SiGe substrates

Applied Physics Letters ◽

10.1063/1.1615310 ◽

2003 ◽

Vol 83 (14) ◽

pp. 2790-2792 ◽

Cited By ~ 3

Author(s):

S. R. Sheng ◽

N. L. Rowell ◽

S. P. McAlister

Keyword(s):

Quantum Wells ◽

Near Infrared ◽

Bulk Crystal ◽

Multiple Quantum Wells ◽

Multiple Quantum ◽

Type Ii

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Lateral Coupling of Self-Assembled Quantum Dots Studied by Near-Field Spectroscopy

MRS Proceedings ◽

10.1557/proc-571-89 ◽

1999 ◽

Vol 571 ◽

Cited By ~ 1

Author(s):

H.D. Robinson ◽

B.B. Goldberg ◽

J.L. Merz

Keyword(s):

Quantum Dots ◽

Additional Data ◽

High Spatial Resolution ◽

Large Fraction ◽

Near Field ◽

Localized States ◽

Emission Lines ◽

Lateral Coupling ◽

Self Assembled ◽

Density Regime

ABSTRACTLateral coupling between separate quantum dots has been observed in a system of In0.55A10.45As self-assembled quantum dots. The experiment was performed by taking photoluminescence excitation (PLE) spectra in the optical near-field at 4.2 K. The high spatial resolution afforded by the near-field technique allows us to resolve individual dots in a density regime where interactions between neighboring dots become apparent. In the PLE spectra, narrow resonances are observed in the emission lines of individual dots. A large fraction of these resonances occur simultaneously in several emission lines, originating from different quantum dots. This is evidence of interdot scattering of carriers, which additional data show to be mediated by localized states at energies below the wetting layer exciton energy. A very rich phonon spectrum generated by the complicated interfaces between barrier and dot material is also evident in the data.

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