High sensitivity apparatus for low optical absorption measurements

1984 ◽  
Vol 56 (1) ◽  
pp. 6-9 ◽  
Author(s):  
L. C. Nistor ◽  
S. V. Nistor ◽  
V. Teodorescu
Keyword(s):  
Optical Absorption ◽  
High Sensitivity ◽  
Absorption Measurements

Comment on ‘‘Optical absorption measurements of hydrogen at megabar pressures’’

1995 ◽  
Vol 52 (2) ◽  
pp. 1405-1407 ◽  
Author(s):  
Arthur L. Ruoff ◽  
Kouros Ghandehari
Keyword(s):  
Optical Absorption ◽  
Absorption Measurements

scholarly journals Bone Chemical Composition Analysis Using Photoacoustic Technique

2020 ◽  
Vol 8 ◽  
Author(s):  
Ting Feng ◽  
Yejing Xie ◽  
Weiya Xie ◽  
Dean Ta ◽  
Qian Cheng
Keyword(s):  
Chemical Composition ◽  
Optical Absorption ◽  
Imaging Techniques ◽  
Diagnostic Technique ◽  
High Sensitivity ◽  
Spectral Unmixing ◽  
Chemical Components ◽  
Composition Analysis ◽  
Feasibility Assessment ◽  
Multi Wavelength

Photoacoustic (PA) signal analysis based on ultrasonic wave detection can provide both high-sensitivity optical contrast information and micro-architectural information which is highly related with the chemical composition of tissue. In this study, the feasibility assessment of bone composition assessment was investigated using the multi-wavelength PA analysis (MWPA) method which could reflect the molecular information. By illuminating a bone specimen using a laser light with wavelength over an optical spectrum ranging from 680 to 950 nm, the optical absorption spectrum of the bone was acquired. Then, with the optical absorption spectra of all optical absorption chemical components in the known bone, a spectral unmixing procedure was performed to quantitatively assess the relative content of each chemical component. The experimental results from rabbit bones show that MWPA method can be used to assess chemical components related to bone metabolism. Our study confirmed that PA technique can be used as a novel bone diagnostic technique by providing new information about the quantity of bone and identifying biomarkers of bone that can improve the current diagnostic imaging techniques.

scholarly journals Absolute Absorption Measurements in Optical Coatings by Laser Induced Deflection

Coatings ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 473 ◽  
Author(s):  
Simon Bublitz ◽  
Christian Mühlig
Keyword(s):  
High Sensitivity ◽  
Absolute Measurement ◽  
Deposition Process ◽  
Intense Laser ◽  
Optical Coatings ◽  
Absolute Calibration ◽  
Laser Applications ◽  
Experimental Findings ◽  
Thermal Absorption ◽  
Absorption Measurements

Absolute measurement of residual absorption in optical coatings is steadily becoming more important in thin film characterization, in particular with respect to high power laser applications. A summary is given on the current ability of the laser induced deflection (LID) technique to serve sensitive photo-thermal absorption measurements combined with reliable absolute calibration based on an electrical heater approach. To account for different measurement requirements, several concepts have been derived to accordingly adapt the original LID concept. Experimental results are presented for prominent UV and deep UV laser wavelengths, covering a variety of factors that critically can influence the absorption properties in optical coatings e.g., deposition process, defects and impurities, intense laser irradiation and surface/interface engineering. The experimental findings demonstrate that by combining high sensitivity with absolute calibration, photo-thermal absorption measurements are able to be a valuable supplement for the characterization of optical thin films and coatings.

Changes in the defect structure of diamond due to high temperature+ high pressure treatment

1975 ◽  
Vol 344 (1636) ◽  
pp. 111-130 ◽  
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
High Temperature ◽  
Optical Absorption ◽  
Defect Structure ◽  
Pressure Treatment ◽  
High Pressure Treatment ◽  
X Ray ◽  
High Temperature High Pressure ◽  
Absorption Measurements

Type la and type IIa diamonds have been heated to temperatures in the range 2000-2300 °C under a pressure of about 4.8 GPa. The changes in the defect structure of these diamonds as a result of the heat treatm ent have been examined by optical absorption measurements, integrated X-ray spike measurements and by electron microscopy. Type la diamonds changed colour from colourless to yellow after being heated for 1 min in the temperature range 2250-2300 °C and it has been shown that the yellowing was due to scattering. The scattering centres responsible were elliptically shaped cracks in the cube planes with their longest dimension in a <110> direction

In situ monitoring the role of citrate in chemical bath deposition of PbS thin films

CrystEngComm ◽  
2016 ◽  
Vol 18 (1) ◽  
pp. 149-156 ◽  
Author(s):  
Sucheta Sengupta ◽  
Maayan Perez ◽  
Alexander Rabkin ◽  
Yuval Golan
Keyword(s):  
Thin Films ◽  
Light Scattering ◽  
Optical Absorption ◽  
Chemical Bath Deposition ◽  
Trisodium Citrate ◽  
In Situ Monitoring ◽  
Cluster Mechanism ◽  
Absorption Measurements

We report the formation of size tunable PbS nanocubes induced by the presence of trisodium citrate during growth of PbS thin films by chemical bath deposition. The presence of citrate induces growth by the cluster mechanism which is monitored by XRD and HRSEM, along with real time light scattering and optical absorption measurements.

Photoacoustic Study of The Effect of 0.9 eV Light Illumination in Semi-Insulating GaAs

1997 ◽  
Vol 484 ◽  
Author(s):  
Atsuhiko Fukuyama ◽  
Yoshito Akashi ◽  
Kenji Yoshino ◽  
Kouji Maeda ◽  
Tetsuo Ikari
Keyword(s):  
Optical Absorption ◽  
Photon Energy ◽  
Metastable State ◽  
Energy Region ◽  
Broad Peak ◽  
Light Illumination ◽  
Transformation Rates ◽  
The Difference ◽  
First Time ◽  
Absorption Measurements

AbstractThe effect of the secondary light illumination of hv = 0.9 eV on the photoquenched and the enhanced states in semi-insulating GaAs are investigated by using piezoelectric photoacoustic (PPA) measurements at 80 K. It is found that the secondary light causes an optical recovery from EL2* to EL2° and this is in agrezment with the result reported by using infrared optical absorption measurements. We observed a broad peak around 0.9 eV after the secondary light illumination for the first time. The most important finding is that the PPA spectra after the secondary light illumination on the quenched and the enhanced states are the same in the whole photon energy region. We concluded that the secondary light of hv = 0.9 eV induces both an optical recovery and generation of metastable state of the EL6 level. The difference of the transformation rates of these two processes explains well the observed complex natures of the PPA signal under the secondary light illumination.

Reply to ‘‘Comment on ‘Optical absorption measurements of hydrogen at megabar pressures’ ’’

1995 ◽  
Vol 52 (2) ◽  
pp. 1408-1410
Author(s):  
Michael Hanfland ◽  
Russell J. Hemley ◽  
Ho-kwang Mao
Keyword(s):  
Optical Absorption ◽  
Absorption Measurements
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