scholarly journals INFRARED PHOTOLUMINESCENCE SPECTRA OF PBS NANOPARTICLES PREPARED BY LANGMUIR–BLODGETT AND LASER ABLATION METHODS

2014 ◽  
Vol 54 (6) ◽  
pp. 426-429 ◽  
Author(s):  
Zdeněk Remes ◽  
Tomas Novak ◽  
Jiri Stuchlik ◽  
The-ha Stuchlikova ◽  
Vladislav Dřínek ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Spectral Range ◽  
Near Infrared ◽  
Infrared Region ◽  
Thin Layers ◽  
Photoluminescence Intensity ◽  
Photoluminescence Spectra ◽  
Colloidal Solutions ◽  
Pbs Nanoparticles ◽  
Langmuir Blodgett

We optimized the optical setup originally designed for the photoluminescence measurements in the spectral range 400‒1100 nm. New design extends the spectral range into the near infrared region 900‒1700 nm and allows the colloidal solutions measurements in cuvettes as well as the measurements of nanoparticles deposited in the form of thin films on glass substrates. The infrared photoluminescence spectra of the PbS nanoparticles prepared by the Langmuir–Blodgett technique show the higher photoluminescence intensity and the shift to the shorter wavelengths compared to the infrared photoluminescence spectra of the PbS nanoparticles prepared by the laser ablation from PbS target. We aslo proved the high stability of PbS nanoparticles prepared in the form of thin layers.

Drastic photoluminescence modulation of an organic molecular crystal with high pressure

2019 ◽  
Vol 3 (8) ◽  
pp. 1510-1517 ◽  
Author(s):  
Junjie Guan ◽  
Chunfang Zhang ◽  
Dexiang Gao ◽  
Xingyu Tang ◽  
Xiao Dong ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Molecular Crystal ◽  
Near Infrared ◽  
Infrared Region ◽  
Photoluminescence Spectra ◽  
Organic Molecular Crystal ◽  
Greenish Yellow ◽  
Near Infrared Region

The pressure-induced phase transition of diphenylfluorenone leads to a drastic redshift of the photoluminescence spectra from greenish-yellow to the near-infrared region.

scholarly journals Неохлаждаемые фотодиоды для регистрации импульсного инфракрасного излучения в спектральном диапазоне 0.9-1.8 мкм

2021 ◽  
Vol 55 (7) ◽  
pp. 607
Author(s):  
Е.В. Куницына ◽  
А.А. Пивоварова ◽  
И.А. Андреев ◽  
Г.Г. Коновалов ◽  
Э.В. Иванов ◽  
...  
Keyword(s):  
Spectral Range ◽  
Infrared Radiation ◽  
Near Infrared ◽  
Infrared Region ◽  
Gasb Layer ◽  
Speed Of Response ◽  
Photovoltaic Mode ◽  
Near Infrared Region ◽  
Neutral Solvent

Uncooled GaSb/GaAlAsSb photodiodes for detecting pulsed infrared radiation in the spectral range of 0.9-1.8 µm have been developed. Active GaSb layer was grown using lead as a neutral solvent in order to reduce the concentration of natural acceptors. The capacity of the photodiodes with a diameter of photosensitive area of 300 µm was 115−135 pF with no bias and 62−70 pF at U=−1.5 V. The photodiode speed of response measured using an InGaAsP/InP laser with a wavelength of 1.55 µm reached tau=42−60 ns in the photovoltaic mode. It is shown experimentally that the photodiodes can be used without cooling to detect the pulsed radiation of lasers and LEDs in the near-infrared region of the spectrum.

scholarly journals Identification of Apple Varieties Using a Multichannel Hyperspectral Imaging System

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5120 ◽  
Author(s):  
Yuping Huang ◽  
Yutu Yang ◽  
Ye Sun ◽  
Haiyan Zhou ◽  
Kunjie Chen
Keyword(s):  
Hyperspectral Imaging ◽  
Spectral Range ◽  
Near Infrared ◽  
Imaging System ◽  
Visible Region ◽  
Infrared Region ◽  
Apple Variety ◽  
Apple Varieties ◽  
Spatially Resolved ◽  
Variety Classification

This paper reports the nondestructive detection of apple varieties using a multichannel hyperspectral imaging system consisting of an illumination fiber and 30 detection fibers arranged at source–detector distances of 1.5–36 mm over the spectral range of 550–1650 nm. Spatially resolved (SR) spectra were obtained for 1500 apples, 500 each of three varieties from the same orchard to avoid environmental and geographical influences. Partial least squares discriminant analysis (PLSDA) models were developed for single SR spectra and spectral combinations to compare their performance of variety detection. To evaluate the effect of spectral range on variety detection, three types of spectra (i.e., visible region: 550–780 nm, near-infrared region: 780–1650 nm, full region: 550–1650 nm) were analyzed and compared. The results showed that the single SR spectra presented a different accuracy for apple variety classification, and the optimal SR spectra varied with spectral types. Spectral combinations had better accuracies for variety detection with best overall classifications of 99.4% for both spectral ranges in the NIR and full regions; however, the spectral combination could not improve the results over the optimal single SR spectra in the visible region. Moreover, the recognition of golden delicious (GD) was better than those of the other two varieties, with the best classification accuracy of 100% for three types of spectra. Overall, the multichannel hyperspectral imaging system provides more spatial-spectral information for the apples, and the results demonstrate that the technique gave excellent classifications, which suggests that the multichannel hyperspectral imaging system has potential for apple variety detection.

Deoxyribonucleic Acid Complexes Based on Cetyltrimethylammonium Thin Layers Deposited on a Polydimethylsiloxane Substrate

2019 ◽  
Author(s):  
Vaclav Prajzler ◽  
Woohyun Jung ◽  
Kyunghwan Oh ◽  
Jakub Cajzl ◽  
Pavla Nekvindova
Keyword(s):  
Deoxyribonucleic Acid ◽  
Near Infrared ◽  
Broad Band ◽  
Infrared Region ◽  
Optical Devices ◽  
Thin Layers ◽  
Refractive Indices ◽  
Pdms Substrate ◽  
Dna Complexes ◽  
Near Infrared Region

This paper presents our research on the optical properties of thin-film deoxyribonucleic acid (DNA) complexes based on cetyltrimethylammonium (DNA-CTMA) deposited onto a polydimethylsiloxane (PDMS) substrate, which may be suitable for the construction of biophotonic devices. The study involved the measurement of Raman spectra, absorption spectra from the visible to near-infrared region and the values of the refractive indices by m-line spectroscopy at five wavelengths (473, 632.8, 964, 1311, and 1552 nm). The samples were proved to have waveguiding properties from visible to infrared spectrum and high contrast of refractive index. Photoluminescence measurement was done under excitation at three wavelengths (355, 405 and 450 nm) and showed one broad band with maxima at 437, 520 and 530 nm depending on the excitation wavelengths. The study has demonstrated that this combination of polymers, because of its unique properties, has a great potential for the implementation of all-polymer structures in the applications of high-density photonics and biocompatible optical devices.

Metastructures for the Giant Enhancement of Raman Scattering in the Near Infrared Spectral Range

JETP Letters ◽  
2020 ◽  
Vol 112 (1) ◽  
pp. 31-36
Author(s):  
V. I. Kukushkin ◽  
V. E. Kirpichev ◽  
E. N. Morozova ◽  
V. V. Solov’ev ◽  
Ya. V. Fedotova ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Spectral Range ◽  
Near Infrared ◽  
Infrared Spectral Range ◽  
Infrared Spectral
Sign in / Sign up

Export Citation Format

Share Document