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SiO2/Nb2O5 multilayer thin films were designed for the special application of an aviation lighting system emitting green light. For optical components in this system to meet requirements such as a high transmittance and durability, SiO2/Nb2O5 multilayer thin films of 60 individual layers were fabricated by a plasma-assisted reactive magnetron sputtering method. As a result, the transmittance spectra were confirmed to have a flat top surface and a square bandwidth. The transmittances of the SiO2/Nb2O5 multilayer thin films in the range of 500 nm to 550 nm was approximately 96.14%. The reason for high transmittance was attributed to the almost matching between the designed and fabricated SiO2/Nb2O5 multilayer thin films. It was found that there was little difference in the total thickness between the designed and fabricated SiO2/Nb2O5 multilayer thin films without interlayer diffusion. The surface roughness and hardness of the SiO2/Nb2O5 multilayer thin films on a glass substrate was 2.32 nm ± 0.19 nm and 6.6 GPa, respectively. These results indicate that SiO2/Nb2O5 multilayer thin films can be applied not only to the optical filters used in aviation lighting devices, but also to various optics applications because of high transmittance. [ABSTRACT FROM AUTHOR]

The formation mechanism of Cd–S–Se quantum dots (QDs) with a CdS/CdSe core–shell structure within a silicate glass system was investigated by monitoring the change in the first excitonic absorption peak of CdSe, CdS, and Cd–S–Se QDs as a function of the heat‐treatment (HT) duration. When a silicate glass containing QD formation components for CdSe or CdS single‐phased QDs was heat‐treated, CdSe QDs grew via Ostwald ripening, whereas CdS QDs hardly formed within the given silicate glass matrix. When the glass, including CdO, ZnSe, and ZnS, was utilized for the synthesis of Cd–S–Se QDs within the glass matrix, Cd–S–Se QDs were successfully formed and exhibited similar growth behavior to CdSe QDs during the initial stage of HT. The structural changes in the QD‐embedded glasses during HT were also monitored by Raman spectroscopy and discussed, and a possible formation mechanism of CdSe/CdS core–shell‐structured QDs within silicate glasses is suggested. [ABSTRACT FROM AUTHOR]

PbO-SiO2-Al2O3-B2O3 (PSAB)-based glasses were prepared in order to determine the feasibility for laser sealing in the form of fiber. To reach a high quality of laser sealing, the tuning capability of CuO and Na2CO3 dopant concentration was examined on thermal, thermo-mechanical, and optical properties of glasses. The difference of thermal expansion coefficient was reduced with codoping of 1 wt% CuO-2 wt% Na2CO3 into the PSAB glass system, and it amounted to 0.34 × 10−6/K. The codoped PSAB glass system reached 100% absorption at 810 nm, which corresponds to the wavelength of laser. The glass fiber with a diameter of 180 μm was successfully pulled from the codoped PSAB glass system. The fluorine-doped tin oxide (FTO) glass substrate using the glass fiber was successfully sealed. It presented a crack-free sealed surface with a sealing strength of about 41 MPa. These results indicate that the PSAB-based glass system in the form of fiber is proved as a laser sealing material in packaging systems. [ABSTRACT FROM AUTHOR]

The thermal expansion coefficient ( TEC) of Ge-Sb-Se glass, within a compositional range suitable for molded lenses capable of transmitting long-wavelength infrared, was analyzed to assess compositional dependence. Unlike other thermal properties, eg, glass transition temperature and dilatometric softening temperature, which are correlated mostly with germanium content, the TEC turned out to behave most sensitively with selenium content. The thermal expansion behavior of this glass was evaluated based on two structural parameters: the mean coordination number and average bond energy ( ABE). It was verified that the relation between TEC and these structural parameters needs to be distinguished in terms of homopolar Se-Se bonds. Specifically, the TEC tends to decrease monotonically as the mean coordination number increases, and there are relatively small discrepancies between Se-sufficient and Se-deficient compositions. The TEC of the Se-sufficient glass appears to have a relatively well-defined correlation with the ABE: the TEC decreases as the ABE increases. However, a much weaker correlation between the TEC and ABE is observed in the Se-deficient glass. The observed thermal expansion behavior of this glass is delineated, with a particular focus on its connection to the structural role of the Se atoms. [ABSTRACT FROM AUTHOR]

Background: As the most abundant protein in human tissues, the use of collagen is essential in the fields of biological science and medicine.Objective: The aim of this study is to investigate the mechanical effect of pulsed laser irradiation on collagen tissue.Methods: With various laser parameters such as peak power, pulse width, and repetition rate, the induced stresses on samples were measured and analyzed. Monte Carlo simulation was performed to investigate the effect of laser parameters on the collagen sample.Results: The results indicated that the magnitude of mechanical stress could be controlled by various laser parameters.Conclusions: This study can be used in biostimulation for therapy and mechanoreceptor stimulation for tactile application. [ABSTRACT FROM AUTHOR]

Background: The evaluation and control of lighting is crucial in physiological, biomedical, and industrial fields. Many kinds of lighting techniques based on LED have been developed due to its advantages.Objective: The aim of this study is to develop the multi-colored LED system for healing purposes.Methods: Light source with three-color chip LEDs was investigated to detect the dominant wavelength.Results: The results show that the additive principle by three-color LEDs can be successfully applied to lighting system by generating a variety of colors.Conclusions: The results are expected to be useful in the field of light therapy and medicine. Applications of the developed light system are lighting therapies such as stimulating blood circulation and digestive processes, and controlling inflammation. [ABSTRACT FROM AUTHOR]

Background: Evaluation of joint movements is essential to choose an appropriate rehabilitation protocol for a patient.Objective: The aim of this study is to suggest an alternative optical technique for measurement of joint angle which is convenient, inexpensive, and can be operated in real time.Methods: According to the principle of the triangulation method, position sensitive detector (PSD) converts reflected light signals into distance-related voltages. Various parameters were investigated to increase detection range and resolution of joint angle measurements.Results: The accuracy of the suggested optical sensor was verified by comparing with a commercial goniometer and 3D motion capture system.Conclusions: This method can be applied to monitor recovery progress for the patient in rehabilitation and sport science. [ABSTRACT FROM AUTHOR]

Measuring joint angles is an important task for therapists to monitor and evaluate a patient's recovery progress. A fiber-optic goniometer with modified fiber tips was developed and employed to measure joint angles. The effects of the fiber tip's angle in various off-center positions of the detector on the output beam pattern were investigated. The proper combination of these variables increased the measuring range of joint angles with asymmetric light signals from the modified fiber tips. With inverse mathematical models and LabVIEW computer program, the joint angle was obtained and displayed in real time. The reference joint angle correlated well with the calculated output angle over the test range. This method can be used not only in hospitals and laboratories, but also at home, with a simple and cost-effective optical sensor. This method can be applied in the field of rehabilitation and sports science. [ABSTRACT FROM AUTHOR]

For diagnostic and therapeutic purposes, the joint angle measurement of a patient after an accident or a surgical operation is significant for monitoring and evaluating the recovering process. This paper proposed an optical fiber sensor for the measurement of angular displacement. The effect of beveled fiber angle on the detected light signal was investigated to find an appropriate mathematical model. Beveled fiber tips redirected the light over a range of angles away from the fiber axis. Inverse polynomial models were applied to directly obtain and display the joint angle change in real time with the Lab-VIEW program. The actual joint angle correlated well with the calculated LabVIEW output angle over the test range. The proposed optical sensor is simple, cost effective, small in size, and can evaluate the joint angle in real time. This method is expected to be useful in the field of rehabilitation and sport science. [ABSTRACT FROM AUTHOR]

For diagnostic and therapeutic purposes, the joint angle measurement of a patient after an accident or a surgical operation is significant for monitoring and evaluating the recovering process. This paper proposed an optical fiber sensor for the measurement of angular displacement. The effect of beveled fiber angle on the detected light signal was investigated to find an appropriate mathematical model. Beveled fiber tips redirected the light over a range of angles away from the fiber axis. Inverse polynomial models were applied to directly obtain and display the joint angle change in real time with the Lab-VIEW program. The actual joint angle correlated well with the calculated LabVIEW output angle over the test range. The proposed optical sensor is simple, cost effective, small in size, and can evaluate the joint angle in real time. This method is expected to be useful in the field of rehabilitation and sport science. [ABSTRACT FROM AUTHOR]

We successfully fabricated Y2O3:RE3+ (RE = Eu, Tb, and Dy) core and core–shell nanophosphors by the molten salt method and sol–gel processes with Y2O3 core size of the order of 100~150 nm. The structural and morphological studies of the RE3+-doped Y2O3 nanophosphors are analyzed by using XRD, SEM and TEM techniques, respectively. The concentration and annealing temperature dependent structural and luminescence characteristics were studied for Y2O3:RE3+ core and core–shell nanophosphors. It is observed that the XRD peaks became narrower as annealing temperature increased in the core–shell nanophosphor. This indicates that annealing at higher temperature improves the crystallinity which in turn enhances the average crystallite size. The emission intensity and quantum yield of the Eu3+-doped Y2O3 core and core–shell nanoparticles increased significantly when annealing temperature is varied from 450 to 550 °C. No considerable variation was noticed in the case of Y2O3:Tb3+ and Y2O3:Dy3+ core and core–shell nanophosphors. [ABSTRACT FROM AUTHOR]

In this paper, the glass systems, TeO2–ZnO–BaO (TZB), TeO2–ZnO–BaO–Nb2O5 (TZB–Nb) and TeO2–ZnO–BaO–MoO3 (TZB–Mo), were fabricated by the traditional melt-quench protocol for use as mid-infrared (mid-IR) transmitting optical material. The effect of Nb2O5 and MoO3 on the key glass material properties was studied through various techniques. From the Raman analysis, it was found that the structural modification was clear with the addition of both Nb2O5 and MoO3 in the TZB system. The transmittance of studied glasses was measured and found that the optical window covered a region from 0.4 to 6 μm. The larger linear refractive index was obtained for the Nb2O5-doped TZB glass system than that of other studied systems. High glass transition temperature, low thermo-mechanical coefficient and high Knoop hardness were noticed in the Nb2O5-doped TZB glass system due to the increase in cross-linking density and rigidity in the tellurite network. The results suggest that the Nb2O5-doped TZB optical glasses could be a promising material for mid-infrared transmitting optics. [ABSTRACT FROM AUTHOR]

In the present study, zinc‐molybdenum‐tellurite glasses are prepared and their thermal, thermo‐mechanical, viscous, and mechanical properties for mid‐IR molded glass lens applications are studied. From the thermal analysis, it is found that the glass transition temperature, onset crystallization temperature, and stability parameters slightly increase with an increase in ZnO content in both series of glasses. Thermal expansion coefficient decreases from 16.56 to 14.67 × 10−6 K−1 as the ZnO content increased from 10 to 30 mol%. For fixed 10 mol% of MoO3 content, Knoop hardness slightly decreases from 3009 to 2842 MPa as ZnO content increases from 10 to 30 mol% whereas it increases for 20 mol% of MoO3. The results indicate that the addition of ZnO and MoO3 contents into the tellurite glass system increases bridging oxygen contribution and in turn network compactness of tellurite matrix. [ABSTRACT FROM AUTHOR]

A facile procedure for compositional screening of chalcogenide glass (CG) is proposed to manage its infrared transmission edge (ω c ) as well as refractive index dispersion (ν) in the long-wavelength infrared (LWIR) range. Both ω c and ν of CG turn out to be interpretable simply in connection with its chemical composition based on a postulation that CG behaves as a single average harmonic oscillator (SAHO). In this SAHO model, ω c is expressed as a function of molar mass and average bond energy, both of which are easily accessible for a given CG composition. Two prototypical CG-forming systems in Ge-Sb-Se and Ge-Sb-S compositions exemplify the empirical compositional dependence of ω c , which further plays a decisive role in determining ν. Following the present approach, a set of highly dispersive CG compositions in the Ge-Sb-S system is newly unveiled together with low-dispersion Ge-Sb-Se glasses. It is then experimentally demonstrated that a doublet lens configuration consisting of convex and concave lenses with low and high ν values, respectively, is able to reduce the optical aberrations. This finding presents an opportunity that ν can be envisaged just based on the compositional ratio of CG, thus facilitating completion of the LWIR Abbe diagram.

Background: As the most abundant protein in human tissues, the use of collagen is essential in the fields of biological science and medicine., Objective: The aim of this study is to investigate the mechanical effect of pulsed laser irradiation on collagen tissue., Methods: With various laser parameters such as peak power, pulse width, and repetition rate, the induced stresses on samples were measured and analyzed. Monte Carlo simulation was performed to investigate the effect of laser parameters on the collagen sample., Results: The results indicated that the magnitude of mechanical stress could be controlled by various laser parameters., Conclusions: This study can be used in biostimulation for therapy and mechanoreceptor stimulation for tactile application.

Background: Evaluation of joint movements is essential to choose an appropriate rehabilitation protocol for a patient., Objective: The aim of this study is to suggest an alternative optical technique for measurement of joint angle which is convenient, inexpensive, and can be operated in real time., Methods: According to the principle of the triangulation method, position sensitive detector (PSD) converts reflected light signals into distance-related voltages. Various parameters were investigated to increase detection range and resolution of joint angle measurements., Results: The accuracy of the suggested optical sensor was verified by comparing with a commercial goniometer and 3D motion capture system., Conclusions: This method can be applied to monitor recovery progress for the patient in rehabilitation and sport science.

Background: The evaluation and control of lighting is crucial in physiological, biomedical, and industrial fields. Many kinds of lighting techniques based on LED have been developed due to its advantages., Objective: The aim of this study is to develop the multi-colored LED system for healing purposes., Methods: Light source with three-color chip LEDs was investigated to detect the dominant wavelength., Results: The results show that the additive principle by three-color LEDs can be successfully applied to lighting system by generating a variety of colors., Conclusions: The results are expected to be useful in the field of light therapy and medicine. Applications of the developed light system are lighting therapies such as stimulating blood circulation and digestive processes, and controlling inflammation.