High-sensitivity near-IR absorption measurements of nanoliter samples in a cavity enhanced fiber sensor

2009 ◽  
Author(s):  
Anthony L. Gomez ◽  
Julia A. Fruetel ◽  
Ray P. Bambha
Keyword(s):  
High Sensitivity ◽  
Fiber Sensor ◽  
Ir Absorption ◽  
Near Ir ◽  
Absorption Measurements

Plasmon-assisted interaction of Si with light, for cancer hyperthermia and electromagnetic energy harvest

2020 ◽  
Vol 92 (2) ◽  
pp. 20101
Author(s):  
Behnam Kheyraddini Mousavi ◽  
Morteza Rezaei Talarposhti ◽  
Farshid Karbassian ◽  
Arash Kheyraddini Mousavi
Keyword(s):  
Silicon Nanowires ◽  
Metallic Nanoparticles ◽  
Near Infrared ◽  
Optical Transition ◽  
Electromagnetic Energy ◽  
Energy Harvest ◽  
Absorption Enhancement ◽  
Ir Absorption ◽  
Absorption Mechanism ◽  
Near Ir

Metal-assisted chemical etching (MACE) is applied for fabrication of silicon nanowires (SiNWs). We have shown the effect of amorphous sheath of SiNWs by treating the nanowires with SF6 and the resulting reduction of absorption bandwidth, i.e. making SiNWs semi-transparent in near-infrared (IR). For the first time, by treating the fabricated SiNWs with copper containing HF∕H2O2∕H2O solution, we have generated crystalline nanowires with broader light absorption spectrum, up to λ = 1 μm. Both the absorption and photo-luminescence (PL) of the SiNWs are observed from visible to IR wavelengths. It is found that the SiNWs have PL at visible and near Infrared wavelengths, which may infer presence of mechanisms such as forbidden gap transitions other can involvement of plasmonic resonances. Non-radiative recombination of excitons is one of the reasons behind absorption of SiNWs. Also, on the dielectric metal interface, the absorption mechanism can be due to plasmonic dissipation or plasmon-assisted generation of excitons in the indirect band-gap material. Comparison between nanowires with and without metallic nanoparticles has revealed the effect of nanoparticles on absorption enhancement. The broader near IR absorption, paves the way for applications like hyperthermia of cancer while the optical transition in near IR also facilitates harvesting electromagnetic energy at a broad spectrum from visible to IR.

Near-IR Absorption Spectra for the Buckminsterfullerene Anions: An Experimental and Theoretical Study

1992 ◽  
Author(s):  
Del R. Lawson ◽  
Daniel L. Feldheim ◽  
Colby A. Foss ◽  
Peter K. Dorhoug ◽  
C. M. Elliott
Keyword(s):  
Absorption Spectra ◽  
Theoretical Study ◽  
Ir Absorption ◽  
Near Ir ◽  
Ir Absorption Spectra

Solid Parahydrogen Thickness Revisited

2019 ◽  
Vol 73 (12) ◽  
pp. 1403-1408 ◽  
Author(s):  
Mario E. Fajardo
Keyword(s):  
Systematic Error ◽  
Absorption Spectroscopy ◽  
Ir Absorption ◽  
Spectroscopy Data ◽  
Previous Approach ◽  
Polarization Effects ◽  
Peak Intensity ◽  
Absorption Measurements

We report updated infrared (IR) absorption measurements on vapor-deposited cryogenic parahydrogen (pH2) solids that indicate a ≈10% systematic error in our previous approach for determining a pH2 solid's thickness (S. Tam and M.E. Fajardo. Appl. Spectrosc. 2001. 55(12): 1634-1644). We provide corrected values for the integrated absorption intensities of the Q1(0)+S0(0) and S1(0)+S0(0) bands calculated over the 4495–4520 cm−1 and 4825–4855 cm−1 regions, respectively. New polarized IR absorption spectroscopy data demonstrate the insensitivity to polarization effects of the peak intensity of the QR(0) phonon sideband near 4228 cm−1. This feature provides an even quicker way for determining the thickness of a pH2 solid than via the integrated absorptions.

On-chip methane sensing by near-IR absorption signatures in a photonic crystal slot waveguide

2011 ◽  
Vol 36 (6) ◽  
pp. 984 ◽  
Author(s):  
Wei-Cheng Lai ◽  
Swapnajit Chakravarty ◽  
Xiaolong Wang ◽  
Cheyun Lin ◽  
Ray T. Chen
Keyword(s):  
Photonic Crystal ◽  
Slot Waveguide ◽  
Ir Absorption ◽  
Near Ir ◽  
On Chip

scholarly journals Absorption and Emission Spectra for C60 Anions

1994 ◽  
Vol 14 (1-3) ◽  
pp. 155-160 ◽  
Author(s):  
Tatsuhisa Kato
Keyword(s):  
Absorption Spectrum ◽  
Absorption Band ◽  
Theoretical Analysis ◽  
Room Temperature ◽  
Emission Spectra ◽  
Mirror Image ◽  
Ir Absorption ◽  
Near Ir ◽  
Laser Experiments ◽  
Ir Bands

Absorption spectra are detected for C60− and C602− produced electrolytically in solution at room temperature. Theoretical analysis of the spectrum of C60− by CNDO/S calculations gives an interpretation of the characteristic near-IR bands, the weak visible bands, and the strong bands in the UV region. The emission spectrum of C60− is a mirror image of the near-IR absorption band, and the detection of the emission reconfirms our original assignment of the absorption spectrum. The nature of the spectrum of C602− is characterized by a similar orbital picture to that of C60−. Further laser experiments of significance are proposed.

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