Nondestructive assessment of apple optical properties during growth by time-resolved reflectance spectroscopy in the orchards

In this work, time-resolved thermal lens and beam deflection methods were applied to determine the thermo-optical properties of Er3+ doped sulfophosphate glass in which different concentrations of Titanium dioxide (TiO2) nanoparticles (NPs) were embedded. Thermal diffusivity (D), thermal conductivity (κ), and the temperature coefficient of the optical path length (ds/dT) were determined as a function of NPs concentrations. Moreover, the growth of TiO2 NPs inside the amorphous glass matrix was evidenced by Transmission Electron Microscopy (TEM) images as well as through optical effects such as refractive index change of the glass. The outcomes indicated relatively high values for D and κ as well as a low ds/dT as required for most optical components used for laser media. The addition of TiO2 NPs with concentration of dopants up to 0.6 mol% improved the optical properties of the glass samples but did not affect its thermal properties. The results indicate that the enhanced optical and thermal performance of the proposed co-doped glass fits the quality standards for materials used in photonic devices.

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DIFFUSE REFLECTANCE SPECTROSCOPY MONTE-CARLO MODELING: ELONGATED ARTERIAL TISSUES OPTICAL PROPERTIES

IFAC Proceedings Volumes ◽

10.3182/20060920-3-fr-2912.00012 ◽

2006 ◽

Vol 39 (18) ◽

pp. 41-46

Author(s):

Emilie Péry ◽

Walter C.P.M. Blondel ◽

Cédric Thomas ◽

Jacques Didelon ◽

François Guillemin

Keyword(s):

Monte Carlo ◽

Optical Properties ◽

Diffuse Reflectance ◽

Diffuse Reflectance Spectroscopy ◽

Reflectance Spectroscopy ◽

Monte Carlo Modeling

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Impact of the ZnO buffer on the optical properties of GaN: time resolved micro-photoluminescence

Materials Science and Engineering B ◽

10.1016/s0921-5107(98)00387-0 ◽

1999 ◽

Vol 59 (1-3) ◽

pp. 163-167 ◽

Cited By ~ 4

Author(s):

A. Hoffmann ◽

J. Holst ◽

A. Kaschner ◽

H. Siegle ◽

J. Christen ◽

...

Keyword(s):

Optical Properties ◽

Time Resolved

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Time-Resolved Reflectance Spectroscopy Applied to the Nondestructive Monitoring of the Internal Optical Properties in Apples

Applied Spectroscopy ◽

10.1366/0003702011953496 ◽

2001 ◽

Vol 55 (10) ◽

pp. 1368-1374 ◽

Cited By ~ 75

Author(s):

Rinaldo Cubeddu ◽

Cosimo D'Andrea ◽

Antonio Pifferi ◽

Paola Taroni ◽

Alessandro Torricelli ◽

...

Keyword(s):

Optical Properties ◽

Industrial Applications ◽

Nondestructive Monitoring ◽

Nondestructive Measurement ◽

Time Resolved ◽

Mean Values ◽

Scattering Coefficients ◽

Scattering Spectra ◽

The Mean ◽

Temporal Dispersion

Time-resolved reflectance has been used for the nondestructive measurement of optical properties in apples. The technique is based on the detection of the temporal dispersion of a short laser pulse injected into the probed medium. The time distribution of re-emitted photons interpreted with a solution of the diffusion equation yields the mean values of the absorption and reduced scattering coefficients of the medium. The proposed technique proved useful for the measurement of the absorption and scattering spectra of different varieties of apples, revealing the spectral shape of chlorophyll. No major variations were observed in the experimental data when the fruit was peeled, showing that the optical properties measured were those of the pulp. With this technique the change in chlorophyll absorption during storage and ripening could be followed. Finally, a compact prototype working at few selected wavelengths was designed and constructed, demonstrating potentialities of the technique for industrial applications.

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