The emittance of well-sized corundum powders in the range between 1-30 micro has been measured by ir interferometry in the 7.5-25 micro region of the spectrum (400-1300 cm(-1)). The spectral features persist for all particle sizes with some interesting relative intensity variations. The temperature of the radiating surface is determined by setting the emittance equal to unity at 1035 cm(-1). At this point it is known that both orientations of corundum have a refractive index close to unity and the absorption coefficient is quite small. Thus both the volume and the surface reflectance terms are negligible and hence the emittance is approx. 1. The same powders have been measured in reflectance using a Cary-White spectrometer. A quantitative comparison is made between the two techniques and Kirchhoff's law is shown to apply experimentally.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1364/AO.8.001639 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Spectral narrowing strategies in multiple resonance thermally activated delayed fluorescence materials.
Chemphyschem
January 2025
South China University of Technology School of Materials Science and Engineering, State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, 381 Wushan Road, 510640, Guangzhou, CHINA.
Multi-resonance thermally activated delayed fluorescence (MR-TADF) materials possess unique advantages of high-efficiency and narrowband emission, which have rapidly occupied an important position in the field of organic light-emitting diodes (OLEDs). In recent years, significant advancements have been made in the development of MR-TADF materials, particularly in achieving spectral narrowing for high-color-purity OLED applications. Based on diverse MR-TADF molecular skeletons, this review summarizes the primary molecular strategies to narrow spectrum by suppressing structural relaxation and intermolecular interactions.
View Article and Find Full Text PDFMid-Infrared High-Power InGaAsSb/AlGaInAsSb Multiple-Quantum-Well Laser Diodes Around 2.9 μm.
Nanomaterials (Basel)
January 2025
Key Laboratory of Optoelectronic Materials and Devices, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
Antimonide laser diodes, with their high performance above room temperature, exhibit significant potential for widespread applications in the mid-infrared spectral region. However, the laser's performance significantly degrades as the emission wavelength increases, primarily due to severe quantum-well hole leakage and significant non-radiative recombination. In this paper, we put up an active region with a high valence band offset and excellent crystalline quality with high luminescence to improve the laser's performance.
View Article and Find Full Text PDFNew highly efficient phosphorescent manganese halides as green and blue emitters.
Dalton Trans
January 2025
Institute of Applied Physics, Vienna University of Technology, Wiedner Hauptstraße 8-10, 1040 Vienna, Austria.
Three new manganese compounds on 5-(pyridin-2-yl)-3-phenyl-1,2,4-triazole (L) basis (HL)[MnBr]·HO (1), (HL)[MnCl] (2) and [MnLCl]·HO (3) have been synthesized and characterized in terms of their structure, photoluminescence (PL), and electroluminescence (EL) properties. Compounds 1 and 2 exhibit bright green luminescence ( ≈ 550 nm) with high quantum yields of 75.1 and 71.
View Article and Find Full Text PDFA circular waveguide-fed conical horn antenna is fabricated using two-photon lithography (TPL) and integrated with a spintronic terahertz radiation emitter source to provide enhanced radiation directivity. In comparison to the bare terahertz radiation source, incorporating the antenna permits a spectral density gain up to 20.5 dB.
View Article and Find Full Text PDFVibronic Effects Analysis of the Substituent Effect on the Spectral Properties of the EMI and CPL of Three [7]Helicene Derivatives.
Molecules
December 2024
School of Physics and Optoelectronics Engineering, Ludong University, Yantai 264005, China.
The substituent effect has a significant influence on the optical properties of spectral shape, width, and wavelength, and the intensities of the maximum peaks of emission (EMI) and circularly polarized luminescence (CPL). In this work, we conducted a systematic theoretical study to investigate how substituents alter the optical response in the EMI and CPL spectra of three [7]helicene derivatives at the vibronic level. To incorporate the vibronic effect, a state-of-the-art time-dependent (TD) method was used to achieve the fully converged spectra.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!