The Cr^3＋：BeAl2O4 crystal, Cr^3＋：LiNbO3 crystal, and ZnO-Al2O3-SiO2 glass-ceramic were obtained by the Czochralski technique, Bridgman method, and melting processing, respectively. The optical absorption and emiss...The Cr^3＋：BeAl2O4 crystal, Cr^3＋：LiNbO3 crystal, and ZnO-Al2O3-SiO2 glass-ceramic were obtained by the Czochralski technique, Bridgman method, and melting processing, respectively. The optical absorption and emission spectra of the above Cr^3＋-incorporated solid-state materials were recorded. The technical parameters for growing high-quality Cr^3＋：BeAl2O4 and Cr^3＋：LINbO3 crystals were obtained. The results indicate that the optical absorption and fluorescence spectra of Cr^3＋ show quite a few differences in various matrixes. The sharp line emissions were observed in the Cr^3＋：BeAl2O4 and Cr^3＋：LiNbO3 crystals. The crystal-field parameters （Dq） for Cr^3＋. in different matrixes were calculated from their corresponding spectra. It is indicated that Cr^3＋：BeAl2O4 and Cr^3＋：LiNbO3 belong to the high-field site crystal, while the Cr^3＋ ZnO-Al2O3-SiO2 glass and glass-ceramic belong to the weak-field site crystal.展开更多
Optical spectroscopy devices are being developed and tested for the screening and diagnosis of oral precancer and cancer lesions. This study reports a device that uses white light for detection of suspicious lesions a...Optical spectroscopy devices are being developed and tested for the screening and diagnosis of oral precancer and cancer lesions. This study reports a device that uses white light for detection of suspicious lesions and green–amber light at 545 nm that detect tissue vascularity on patients with several suspicious oral lesions. The clinical grading of vascularity was compared to the histological grading of the biopsied lesions using specific biomarkers. Such a device, in the hands of dentists and other health professionals, could greatly increase the number of oral cancerous lesions detected in early phase. The purpose of this study is to correlate the clinical grading of tissue vascularity in several oral suspicious lesions using the IdentafiH system with the histological grading of the biopsied lesions using specific vascular markers. Twenty-one patients with various oral lesions were enrolled in the study. The lesions were visualized using IdentafiH device with white light illumination, followed by visualization of tissue autofluorescence and tissue reflectance. Tissue biopsied was obtained from the all lesions and both histopathological and immunohistochemical studies using a vascular endothelial biomarker（CD34） were performed on these tissue samples. The clinical vascular grading using the green–amber light at 545 nm and the expression pattern and intensity of staining for CD34 in the different biopsies varied depending on lesions, grading ranged from 1 to3. The increase in vascularity was observed in abnormal tissues when compared to normal mucosa, but this increase was not limited to carcinoma only as hyperkeratosis and other oral diseases, such as lichen planus, also showed increase in vascularity. Optical spectroscopy is a promising technology for the detection of oral mucosal abnormalities; however, further investigations with a larger population group is required to evaluate the usefulness of these devices in differentiating benign lesions from potentially malignant lesions.展开更多
The （60 - x）Bi2O3 - xGeO2-30B2O3-10ZnO （x = 5, 10, 20, 30 molar percent） glasses doped with Er^3＋ and Er^3＋/Yb^3＋ were fabricated using the melting method. The thermal stability of the glasses was studied with ...The （60 - x）Bi2O3 - xGeO2-30B2O3-10ZnO （x = 5, 10, 20, 30 molar percent） glasses doped with Er^3＋ and Er^3＋/Yb^3＋ were fabricated using the melting method. The thermal stability of the glasses was studied with their DTA curves. The results show that the difference between the glass transition temperature and the crystallization onset temperature increases with the increase of GeO2 content, indicating that the thermal stability of the glass has become better. The absorption spectra were recorded and the stimulated emission cross sections were calculated using the McCumber theory. The Ω2, O4, and Ω6 parameters,the transition probability, the radiative lifetime, and the fluorescence branch ratio of Er^3＋ for optical transition were calculated from their absorption spectra in terms of reduced matrix U^（t）（λ = 2, 4, 6） character for optical transitions. The infrared emission of Er^3＋ was measured upon excitation with 970 nm light and the full width at half-maximum （FWHM） was estimated from the emission spectra. The pumping efficiency and the intensity of the emission at the 1.54 μm band of Er^3＋ were enhanced considerably by co-doping Yb^3＋ .展开更多
High quality LiLuF4 single crystals doped with various Pr3+ ions were synthesized by a vertical Bridgman method in completely sealed platinum crucibles. The excitation spectra spans from 420 nm to 500 nm. The prepared...High quality LiLuF4 single crystals doped with various Pr3+ ions were synthesized by a vertical Bridgman method in completely sealed platinum crucibles. The excitation spectra spans from 420 nm to 500 nm. The prepared single crystals exhibit a blue band at 480 nm(3P0→3H4), a green band at 522 nm (3P1→3H5), and a red band at 605 nm (1D2→3H4)when excited at 446 nm;their corresponding average lifetimes are 38.5μs, 37.3μs, and 36.8μs, respectively, which are much longer than those in oxide single crystals. The effects of excitation wavelength and doping concentration on emission intensities and chromaticity coordinates are investigated. The optimal Pr3+ concentration is confirmed to be 0.5%.The temperature dependent emission shows that the emission intensity constantly decreases with the increase of temperature from 298 K to 443 K due to the enhancement of nonradiative quenching at high temperature. The 3P0→3H4 transition is the most vulnerable to temperature, followed by the 3P1→3H5 transition and 1D2→3H4 transition.展开更多
The （60 - x） Bi2O3-xGeO2-30B2O3-10ZnO （x = 5, 10, 20, 30 molar percent） glasses doped with Er^3＋ and Er^3＋/Yb^3＋ were fabricated by melting method. The thermal stability of the glasses was studied by their DTA ...The （60 - x） Bi2O3-xGeO2-30B2O3-10ZnO （x = 5, 10, 20, 30 molar percent） glasses doped with Er^3＋ and Er^3＋/Yb^3＋ were fabricated by melting method. The thermal stability of the glasses was studied by their DTA curves. The results indicate that the difference between the glass transition temperature and the crystallization onset temperature increase as increase of GeO2 content, indicating that the thermal stability of the glass becomes better. The absorption spectra were recorded. The stimulated emission cross sections were calculated by McCumber theory. The Ω2, Ω4, and Ω6 parameters, transition probability, radiative lifetime, fluorescence branch ratio of Er^3＋ for optical transition were calculated from their absorption spectra in terms of reduced matrix U^（1）（λ = 2, 4, 6） character for optical transitions. The infrared emission was measured by excitation with 970 nm light and the FWHM was estimated from their emission spectra. The pumping efficiency and the intensity of emission at the band of 1.54 μm are enhanced greatly by addition of Y2O3.展开更多
The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 an...The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 and 600°C.The values of the cross point between the curves of the real and imaginary parts of the optical conductivity ɑ_1 and ɑ_1 with energy axis of films exhibit values that correspond to optical gaps and are about 3.25-3.3 eV. The maxima of peaks in plots dR/dλ and dT/dλ versus wavelength of films exhibit optical gaps at about 3.12-3.25 eV.The values of the fundamental indirect band gap obtained from the Tauc model are at about 3.14-3.2 eV. It can be seen that films annealed at 600°C have the minimum indirect optical band gap at about 3.15 eV. The films annealed at 600°C have Urbach＇s energy minimum of 1.38 eV and hence have minimum disorder. The dispersion energy d of films annealed at 500°C has the minimum value of 43 eV.展开更多
A dual-route optical emission spectroscopy(D-OES)diagnostic is newly developed to monitor the optical emission from the X-point plasma region on the HL-2 A tokamak.This diagnostic is composed of an imaging system,a be...A dual-route optical emission spectroscopy(D-OES)diagnostic is newly developed to monitor the optical emission from the X-point plasma region on the HL-2 A tokamak.This diagnostic is composed of an imaging system,a beam-splitting system for dual-route measurements,fiber bundles,a spectrometer system,and a control and acquisition system.One route is used to obtain wide-spectral-range spectra,and the other route is used to acquire high-wavelengthresolution line shapes.The spectral resolution of the wide-range spectrometers is 0.8 nm with a coverage of 800 nm(@200-1000 nm).The spectral resolution of the high-resolution spectrometer is 0.01 nm with a coverage of 6 nm(@200-660 nm).The spatial resolution of each route of D-OES is about 4 cm with 11 channels.The temporal resolution is 16 ms at maximum in the single-channel mode.Wide-range spectra(containing Balmer series and a Fulcher band)and highly resolved Ha line shapes are obtained by D-OES in the hydrogen glow discharge in the lab.D-OES measurements are carried out in the high-density deuterium experiments of HL-2A.The electron density n_(e)and deuterium temperature T_(D) in the X-point multifaceted asymmetric radiation from the edge(MARFE)region are derived simultaneously by fitting the measured D_(a) shape.The density n_(e)is observed to increase from~8.7×10^(18)m^(-3)to~7.8×10^(19)m^(-3),and the temperature T_(D)drops from~14.4 eV to~2.3 eV after the onset of MARFE in the discharge#38260.展开更多
A highly transparent Eu3＋-doped CaGdA104 （CGA） single crystal is grown by the floating zone method. The segregation coefficient, x ray diffraction, and x ray rocking curve are detected, and the results reveal that ...A highly transparent Eu3＋-doped CaGdA104 （CGA） single crystal is grown by the floating zone method. The segregation coefficient, x ray diffraction, and x ray rocking curve are detected, and the results reveal that the single crystal is of high quality. The f-f transitions of Eu3＋ in the host lattice are discussed. The 5D0-7F2 emis- sion transition at 621 nm （red light） is dominant over the 5D0-7F1 emission transitions at 591 and 599 nm （orange light）, agreeing well with the random crystal environment of Eu3＋ ions in a CGA crystal. The decay time of Eu：5D0 is measured to be 1.02 ms. All the results show that the Eu：CGA crystal has good optical char- acterization and promises to be an excellent red- fluorescence material.展开更多
We perform optical spectroscopy measurement on single-crystal samples of Sr3Rh4Sn13 and （Sr0.5Ca0.5）3Rh4Sn13. Formation of CDW energy gap was clearly observed for both single-crystal samples when they undergo the ph...We perform optical spectroscopy measurement on single-crystal samples of Sr3Rh4Sn13 and （Sr0.5Ca0.5）3Rh4Sn13. Formation of CDW energy gap was clearly observed for both single-crystal samples when they undergo the phase transitions. The existence of residual Drude components in σ1（ω） below Tcow indicates that the Fermi surface is only partially gapped in the CDW state. The obtained value of 2A/kBTcow is roughly 13 for both Sr3Rh4Sn13 and （Sr0.5Ca0.5）3Rh4Sn13 compounds, which is considerably larger than the mean-field value based on the weak-coupling BCS theory. The measurements provide optical evidence for the strong coupling characteristics of the CDW phase transition.展开更多
The long-path differential optical absorption spectroscopy （LP-DOAS） technique was developed to mea- sure nighttime atmospheric nitrate radical （NO3） concentrations. An optimized retrieval method, resulting in a s...The long-path differential optical absorption spectroscopy （LP-DOAS） technique was developed to mea- sure nighttime atmospheric nitrate radical （NO3） concentrations. An optimized retrieval method, resulting in a small residual structure and low detection limits, was developed to retrieve NO3. The time series of the NO3 concentration were collected from 17 to 24 March, 2006, where a nighttime average value of 15.8 ppt was observed. The interfering factors and errors are also discussed. These results indicate that the DOAS technique provides an essential tool for the quantification of NO3 concentration and in the study of its effects upon nighttime chemistry.展开更多
Optical emission spectroscopy was used to study a gas mixture glow discharge of CO2 and N2 at a total pressure of 1.2 Torr, a power of 100 W and a flow of 16.5 L/min. The emission bands were measured in the wavelength...Optical emission spectroscopy was used to study a gas mixture glow discharge of CO2 and N2 at a total pressure of 1.2 Torr, a power of 100 W and a flow of 16.5 L/min. The emission bands were measured in the wavelength range of 200 nm to 900 nm. The principal species observed were O2^＋ （A^2П→ X^2П）, CO^＋ （A^2П→X^2∑）, N2^＋ （B^2∑u＋ → X^2∑g^＋）, CO2^＋ （A^2∏ → X^2∏）, N2（C^3∏u → B^3∏g）, O2（b^1∑g^＋→ X^3∑g^-）, and CO （a^r3∑→a^3∏）. The behavior of the band intensities as a function of the N2 percentage is consistent with recent Monte Carlo simulations. The electron temperature and ion density were determined by a double Langmuir probe. The electron temperature was found in the range of 1.55 eV to 2.93 eV, and the electron concentration in the order of 10^10 cm^-3. The electron temperature and ion density at pure N2 and pure CO2 agree with previous measurements.展开更多
The spectral emission and plasma parameters of SnO2 plasmas have been investigated. A planar ceramic SnO2 target was irradiated by a CO2 laser with a full width at half maximmn of 80 ns. The temporal behavior of the s...The spectral emission and plasma parameters of SnO2 plasmas have been investigated. A planar ceramic SnO2 target was irradiated by a CO2 laser with a full width at half maximmn of 80 ns. The temporal behavior of the specific emission lines from the SnO2 plasma was characterized. The intensities of Sn I and Sn Ⅱ lines first increased, and then decreased with the delay time. The results also showed a faster decay of Sn I atoms than that of Sn II ionic species. The temporal evolutions of the SnO2 plasma parameters （electron temperature and density） were deduced. The measured temperature and density of SnO2 plasma are 4.38 eV to 0.5 eV and 11.38×1017 cm 3 to 1.1×1017^ cm-3, for delay times between 0.1 μs and 2.2 #s. We also investigated the effect of the laser pulse energy on Sn02 plasma.展开更多
A Maxwellian electron energy distribution function （EEDF） is often assumed when using the optical emission line-ratio method to determine the electron temperature in low- temperature plasmas. However, in many cases,...A Maxwellian electron energy distribution function （EEDF） is often assumed when using the optical emission line-ratio method to determine the electron temperature in low- temperature plasmas. However, in many cases, non-Maxwellian EEDFs can be formed due to the non-local electron heating or the inelastic-collisional energy loss processes. In this work, with a collisional-radiative model, we propose an approach to obtain the non-Maxwellian EEDF with a ＇two-temperature structure＇ from the emission line-ratios of Paschen 2p levels of argon and kryp- ton atoms. For applications of this approach in reactive gas （CF4, O2, etc） discharges that contain argon and krypton, recommendations of some specific emission line-ratios are provided, according to their sensitivities to the EEDF variation. The kinetic processes of the relevant excited atoms are also discussed in detail.展开更多
Silicon etching is an essential process in various applications,and a major challenge for etching process is anisotropic high aspect ratio etching characteristics.The etch profile is determined by the plasma parameter...Silicon etching is an essential process in various applications,and a major challenge for etching process is anisotropic high aspect ratio etching characteristics.The etch profile is determined by the plasma parameters and process parameters.In this study,the plasma state with each process parameters were analyzed through the optical emission spectroscopy(OES)plasma diagnostic sensor by both chemical and physical approaches.Electron temperature and electron density were additionally acquired using the corona model with OES data that provides chemical species information,and the etch profile was evaluated through scanning electron microscope measurement data.The results include changes in profile with gas ratio,bias power,and pressure.We figure out that factors like ion energy and ion angular distribution as well as chemical reaction affect the anisotropic profile.展开更多
Atmospheric pressure micro-discharges in helium gas with a mixture of 0.5%water vapor between two pin electrodes are generated with nanosecond overvoltage pulses.The temporal and spatial characteristics of the dischar...Atmospheric pressure micro-discharges in helium gas with a mixture of 0.5%water vapor between two pin electrodes are generated with nanosecond overvoltage pulses.The temporal and spatial characteristics of the discharges are investigated by means of time-resolved imaging and optical emission spectroscopy with respect to the discharge morphology,gas temperature,electron density,and excited species.The evolution of micro-discharges is captured by intensified CCD camera and electrical properties.The gas temperature is diagnosed by a two-temperature fit to the ro-vibrational OH(A^(2)Σ^(+)–X^П(2),0–0)emission band and is found to remain low at 425 K during the discharge pulses.The profile of electron density performed by the Stark broadening of Ha 656.1-nm and He I 667.8-nm lines is uniform across the discharge gap at the initial of discharge and reaches as high as 10^(23)m^(-3).The excited species of He,OH,and H show different spatio-temporal behaviors from each other by the measurement of their emission intensities,which are discussed qualitatively in regard of their plasma kinetics.展开更多
This paper reports that the optical emission spectroscopy （OES） is used to monitor the plasma during the deposition process of hydrogenated microcrystalline silicon films in a very high frequency plasma enhanced che...This paper reports that the optical emission spectroscopy （OES） is used to monitor the plasma during the deposition process of hydrogenated microcrystalline silicon films in a very high frequency plasma enhanced chemical vapour deposition system. The OES intensities （Sill^＊, H^＊ and H^＊β） are investigated by varying the deposition parameters. The result shows that the discharge power, silane concentrations and substrate temperature affect the OES intensities. When the discharge power at silane concentration of 4% increases, the OES intensities increase first and then are constant, the intensities increase with the discharge power monotonously at silane concentration of 6%. The SiH^＊ intensity increases with silane concentration, while the intensities of H^＊α and H^＊β increase first and then decrease. When the substrate temperature increases, the SiH^＊ intensity decreases and the intensities of H^＊α and H^＊β are constant. The correlation between the intensity ratio of IH^＊α/ISiH^＊ and the crystalline volume fraction （Xc） of films is confirmed.展开更多
Optical emission spectroscopy and Langmuir Probe diagnostics were incorporated into the experiment, in which dust particles were formed in-situ by using reactive mixture gases （SiHa/C2H4/Ar） in a radio-frequency （R...Optical emission spectroscopy and Langmuir Probe diagnostics were incorporated into the experiment, in which dust particles were formed in-situ by using reactive mixture gases （SiHa/C2H4/Ar） in a radio-frequency （RF） discharge plasma. The excitation temperature was first calculated by combining several optical emission spectra of argon lines and using a Boltzmann distribution to fit the experimental data, then the excitation temperature as functions of both gas pressure and RF power in SiH4/C2Ha/Ar discharges for different discharge conditions were obtained. Correspondingly, based on the measurement of the electron temperature by a Langmuir probe, the excitation temperature was compared with the electron temperature, and some discussions were presented. Finally the emission intensities of spectral lines of Si 390.6 ran, Si2＋ 380.6 nm and C＋ 426.7 nm were measured and presented as functions of pressure, RF power and flow rate of SiH4/C2H4.展开更多
基金This work is financially supported by the Project of Science and Technology of Zhejiang Province (No. 011066)Project of Education Committee of Zhejiang Province (No. 20010231)the Doctoral Science Foundation of Ningbo City (No. 02J20101-12)the Personal Bureau of Ningbo City, China (No. 2002182).
文摘The Cr^3＋：BeAl2O4 crystal, Cr^3＋：LiNbO3 crystal, and ZnO-Al2O3-SiO2 glass-ceramic were obtained by the Czochralski technique, Bridgman method, and melting processing, respectively. The optical absorption and emission spectra of the above Cr^3＋-incorporated solid-state materials were recorded. The technical parameters for growing high-quality Cr^3＋：BeAl2O4 and Cr^3＋：LINbO3 crystals were obtained. The results indicate that the optical absorption and fluorescence spectra of Cr^3＋ show quite a few differences in various matrixes. The sharp line emissions were observed in the Cr^3＋：BeAl2O4 and Cr^3＋：LiNbO3 crystals. The crystal-field parameters （Dq） for Cr^3＋. in different matrixes were calculated from their corresponding spectra. It is indicated that Cr^3＋：BeAl2O4 and Cr^3＋：LiNbO3 belong to the high-field site crystal, while the Cr^3＋ ZnO-Al2O3-SiO2 glass and glass-ceramic belong to the weak-field site crystal.
文摘Optical spectroscopy devices are being developed and tested for the screening and diagnosis of oral precancer and cancer lesions. This study reports a device that uses white light for detection of suspicious lesions and green–amber light at 545 nm that detect tissue vascularity on patients with several suspicious oral lesions. The clinical grading of vascularity was compared to the histological grading of the biopsied lesions using specific biomarkers. Such a device, in the hands of dentists and other health professionals, could greatly increase the number of oral cancerous lesions detected in early phase. The purpose of this study is to correlate the clinical grading of tissue vascularity in several oral suspicious lesions using the IdentafiH system with the histological grading of the biopsied lesions using specific vascular markers. Twenty-one patients with various oral lesions were enrolled in the study. The lesions were visualized using IdentafiH device with white light illumination, followed by visualization of tissue autofluorescence and tissue reflectance. Tissue biopsied was obtained from the all lesions and both histopathological and immunohistochemical studies using a vascular endothelial biomarker（CD34） were performed on these tissue samples. The clinical vascular grading using the green–amber light at 545 nm and the expression pattern and intensity of staining for CD34 in the different biopsies varied depending on lesions, grading ranged from 1 to3. The increase in vascularity was observed in abnormal tissues when compared to normal mucosa, but this increase was not limited to carcinoma only as hyperkeratosis and other oral diseases, such as lichen planus, also showed increase in vascularity. Optical spectroscopy is a promising technology for the detection of oral mucosal abnormalities; however, further investigations with a larger population group is required to evaluate the usefulness of these devices in differentiating benign lesions from potentially malignant lesions.
文摘The （60 - x）Bi2O3 - xGeO2-30B2O3-10ZnO （x = 5, 10, 20, 30 molar percent） glasses doped with Er^3＋ and Er^3＋/Yb^3＋ were fabricated using the melting method. The thermal stability of the glasses was studied with their DTA curves. The results show that the difference between the glass transition temperature and the crystallization onset temperature increases with the increase of GeO2 content, indicating that the thermal stability of the glass has become better. The absorption spectra were recorded and the stimulated emission cross sections were calculated using the McCumber theory. The Ω2, O4, and Ω6 parameters,the transition probability, the radiative lifetime, and the fluorescence branch ratio of Er^3＋ for optical transition were calculated from their absorption spectra in terms of reduced matrix U^（t）（λ = 2, 4, 6） character for optical transitions. The infrared emission of Er^3＋ was measured upon excitation with 970 nm light and the full width at half-maximum （FWHM） was estimated from the emission spectra. The pumping efficiency and the intensity of the emission at the 1.54 μm band of Er^3＋ were enhanced considerably by co-doping Yb^3＋ .
基金supported by the National Natural Science Foundation of China(No.51772159)the Natural Science Foundation of Zhejiang Province(No.LZ17E020001)K.C.Wong Magna Fund in Ningbo University
文摘High quality LiLuF4 single crystals doped with various Pr3+ ions were synthesized by a vertical Bridgman method in completely sealed platinum crucibles. The excitation spectra spans from 420 nm to 500 nm. The prepared single crystals exhibit a blue band at 480 nm(3P0→3H4), a green band at 522 nm (3P1→3H5), and a red band at 605 nm (1D2→3H4)when excited at 446 nm;their corresponding average lifetimes are 38.5μs, 37.3μs, and 36.8μs, respectively, which are much longer than those in oxide single crystals. The effects of excitation wavelength and doping concentration on emission intensities and chromaticity coordinates are investigated. The optimal Pr3+ concentration is confirmed to be 0.5%.The temperature dependent emission shows that the emission intensity constantly decreases with the increase of temperature from 298 K to 443 K due to the enhancement of nonradiative quenching at high temperature. The 3P0→3H4 transition is the most vulnerable to temperature, followed by the 3P1→3H5 transition and 1D2→3H4 transition.
文摘The （60 - x） Bi2O3-xGeO2-30B2O3-10ZnO （x = 5, 10, 20, 30 molar percent） glasses doped with Er^3＋ and Er^3＋/Yb^3＋ were fabricated by melting method. The thermal stability of the glasses was studied by their DTA curves. The results indicate that the difference between the glass transition temperature and the crystallization onset temperature increase as increase of GeO2 content, indicating that the thermal stability of the glass becomes better. The absorption spectra were recorded. The stimulated emission cross sections were calculated by McCumber theory. The Ω2, Ω4, and Ω6 parameters, transition probability, radiative lifetime, fluorescence branch ratio of Er^3＋ for optical transition were calculated from their absorption spectra in terms of reduced matrix U^（1）（λ = 2, 4, 6） character for optical transitions. The infrared emission was measured by excitation with 970 nm light and the FWHM was estimated from their emission spectra. The pumping efficiency and the intensity of emission at the band of 1.54 μm are enhanced greatly by addition of Y2O3.
文摘The optical reflectance and transmittance spectra in the wavelength range of 300-2500 nm are used to compute the absorption coefficient of zinc oxide films annealed at different post-annealing temperatures 400, 500 and 600°C.The values of the cross point between the curves of the real and imaginary parts of the optical conductivity ɑ_1 and ɑ_1 with energy axis of films exhibit values that correspond to optical gaps and are about 3.25-3.3 eV. The maxima of peaks in plots dR/dλ and dT/dλ versus wavelength of films exhibit optical gaps at about 3.12-3.25 eV.The values of the fundamental indirect band gap obtained from the Tauc model are at about 3.14-3.2 eV. It can be seen that films annealed at 600°C have the minimum indirect optical band gap at about 3.15 eV. The films annealed at 600°C have Urbach＇s energy minimum of 1.38 eV and hence have minimum disorder. The dispersion energy d of films annealed at 500°C has the minimum value of 43 eV.
基金supported by the National MCF Energy R&D Program of China(Nos.2018YFE0301102,2022YFE03100004 and 2018YFE 0303102)National Natural Science Foundation of China(Nos.12375210 and 12305238)the Sichuan Natural Science Foundation(Nos.2022NSFSC1791,2022JDRC0014 and 2022TFQCCXTD)。
文摘A dual-route optical emission spectroscopy(D-OES)diagnostic is newly developed to monitor the optical emission from the X-point plasma region on the HL-2 A tokamak.This diagnostic is composed of an imaging system,a beam-splitting system for dual-route measurements,fiber bundles,a spectrometer system,and a control and acquisition system.One route is used to obtain wide-spectral-range spectra,and the other route is used to acquire high-wavelengthresolution line shapes.The spectral resolution of the wide-range spectrometers is 0.8 nm with a coverage of 800 nm(@200-1000 nm).The spectral resolution of the high-resolution spectrometer is 0.01 nm with a coverage of 6 nm(@200-660 nm).The spatial resolution of each route of D-OES is about 4 cm with 11 channels.The temporal resolution is 16 ms at maximum in the single-channel mode.Wide-range spectra(containing Balmer series and a Fulcher band)and highly resolved Ha line shapes are obtained by D-OES in the hydrogen glow discharge in the lab.D-OES measurements are carried out in the high-density deuterium experiments of HL-2A.The electron density n_(e)and deuterium temperature T_(D) in the X-point multifaceted asymmetric radiation from the edge(MARFE)region are derived simultaneously by fitting the measured D_(a) shape.The density n_(e)is observed to increase from~8.7×10^(18)m^(-3)to~7.8×10^(19)m^(-3),and the temperature T_(D)drops from~14.4 eV to~2.3 eV after the onset of MARFE in the discharge#38260.
基金supported by the Natural Science Foundation of Shanghai under Grant No.15ZR1444700
文摘A highly transparent Eu3＋-doped CaGdA104 （CGA） single crystal is grown by the floating zone method. The segregation coefficient, x ray diffraction, and x ray rocking curve are detected, and the results reveal that the single crystal is of high quality. The f-f transitions of Eu3＋ in the host lattice are discussed. The 5D0-7F2 emis- sion transition at 621 nm （red light） is dominant over the 5D0-7F1 emission transitions at 591 and 599 nm （orange light）, agreeing well with the random crystal environment of Eu3＋ ions in a CGA crystal. The decay time of Eu：5D0 is measured to be 1.02 ms. All the results show that the Eu：CGA crystal has good optical char- acterization and promises to be an excellent red- fluorescence material.
基金supported by the National Natural Science Foundation of China(Grant Nos.11327806,and GZ1123)the National Key Research and Development Program of China(Grant No.2016YFA0300902)the Ministry of Science and Technology of Taiwan(Grant No.MOST-103-2112-M-006-014-MY3)(CSL)
文摘We perform optical spectroscopy measurement on single-crystal samples of Sr3Rh4Sn13 and （Sr0.5Ca0.5）3Rh4Sn13. Formation of CDW energy gap was clearly observed for both single-crystal samples when they undergo the phase transitions. The existence of residual Drude components in σ1（ω） below Tcow indicates that the Fermi surface is only partially gapped in the CDW state. The obtained value of 2A/kBTcow is roughly 13 for both Sr3Rh4Sn13 and （Sr0.5Ca0.5）3Rh4Sn13 compounds, which is considerably larger than the mean-field value based on the weak-coupling BCS theory. The measurements provide optical evidence for the strong coupling characteristics of the CDW phase transition.
文摘The long-path differential optical absorption spectroscopy （LP-DOAS） technique was developed to mea- sure nighttime atmospheric nitrate radical （NO3） concentrations. An optimized retrieval method, resulting in a small residual structure and low detection limits, was developed to retrieve NO3. The time series of the NO3 concentration were collected from 17 to 24 March, 2006, where a nighttime average value of 15.8 ppt was observed. The interfering factors and errors are also discussed. These results indicate that the DOAS technique provides an essential tool for the quantification of NO3 concentration and in the study of its effects upon nighttime chemistry.
基金supported by UAEM 2260/06, UAEM 2362/2006U, PROMEP FE018/2003 of Mexico
文摘Optical emission spectroscopy was used to study a gas mixture glow discharge of CO2 and N2 at a total pressure of 1.2 Torr, a power of 100 W and a flow of 16.5 L/min. The emission bands were measured in the wavelength range of 200 nm to 900 nm. The principal species observed were O2^＋ （A^2П→ X^2П）, CO^＋ （A^2П→X^2∑）, N2^＋ （B^2∑u＋ → X^2∑g^＋）, CO2^＋ （A^2∏ → X^2∏）, N2（C^3∏u → B^3∏g）, O2（b^1∑g^＋→ X^3∑g^-）, and CO （a^r3∑→a^3∏）. The behavior of the band intensities as a function of the N2 percentage is consistent with recent Monte Carlo simulations. The electron temperature and ion density were determined by a double Langmuir probe. The electron temperature was found in the range of 1.55 eV to 2.93 eV, and the electron concentration in the order of 10^10 cm^-3. The electron temperature and ion density at pure N2 and pure CO2 agree with previous measurements.
基金supported by National Natural Science Foundation of China(No.11304235)the Director Fund of WNLO
文摘The spectral emission and plasma parameters of SnO2 plasmas have been investigated. A planar ceramic SnO2 target was irradiated by a CO2 laser with a full width at half maximmn of 80 ns. The temporal behavior of the specific emission lines from the SnO2 plasma was characterized. The intensities of Sn I and Sn Ⅱ lines first increased, and then decreased with the delay time. The results also showed a faster decay of Sn I atoms than that of Sn II ionic species. The temporal evolutions of the SnO2 plasma parameters （electron temperature and density） were deduced. The measured temperature and density of SnO2 plasma are 4.38 eV to 0.5 eV and 11.38×1017 cm 3 to 1.1×1017^ cm-3, for delay times between 0.1 μs and 2.2 #s. We also investigated the effect of the laser pulse energy on Sn02 plasma.
基金supported by National Natural Science Foundation of China （Nos. 11075093 and 10935006） and the China Postdoctoral Science Foundation （No. 20100480327）
文摘A Maxwellian electron energy distribution function （EEDF） is often assumed when using the optical emission line-ratio method to determine the electron temperature in low- temperature plasmas. However, in many cases, non-Maxwellian EEDFs can be formed due to the non-local electron heating or the inelastic-collisional energy loss processes. In this work, with a collisional-radiative model, we propose an approach to obtain the non-Maxwellian EEDF with a ＇two-temperature structure＇ from the emission line-ratios of Paschen 2p levels of argon and kryp- ton atoms. For applications of this approach in reactive gas （CF4, O2, etc） discharges that contain argon and krypton, recommendations of some specific emission line-ratios are provided, according to their sensitivities to the EEDF variation. The kinetic processes of the relevant excited atoms are also discussed in detail.
基金supported by the Koran Ministry of Trade,Industry&Energy(MOTIE:GID:20006499)via KSRC(Korea Semiconductor Research Consortium)support program。
文摘Silicon etching is an essential process in various applications,and a major challenge for etching process is anisotropic high aspect ratio etching characteristics.The etch profile is determined by the plasma parameters and process parameters.In this study,the plasma state with each process parameters were analyzed through the optical emission spectroscopy(OES)plasma diagnostic sensor by both chemical and physical approaches.Electron temperature and electron density were additionally acquired using the corona model with OES data that provides chemical species information,and the etch profile was evaluated through scanning electron microscope measurement data.The results include changes in profile with gas ratio,bias power,and pressure.We figure out that factors like ion energy and ion angular distribution as well as chemical reaction affect the anisotropic profile.
基金supported by the National Natural Science Foundation of China(Grant No.51806186)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.20KJB140025)+1 种基金the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20181050)the Scientific Research Project for the Introduction Talent of Yancheng Institute of Technology(Grant No.XJR2020)。
文摘Atmospheric pressure micro-discharges in helium gas with a mixture of 0.5%water vapor between two pin electrodes are generated with nanosecond overvoltage pulses.The temporal and spatial characteristics of the discharges are investigated by means of time-resolved imaging and optical emission spectroscopy with respect to the discharge morphology,gas temperature,electron density,and excited species.The evolution of micro-discharges is captured by intensified CCD camera and electrical properties.The gas temperature is diagnosed by a two-temperature fit to the ro-vibrational OH(A^(2)Σ^(+)–X^П(2),0–0)emission band and is found to remain low at 425 K during the discharge pulses.The profile of electron density performed by the Stark broadening of Ha 656.1-nm and He I 667.8-nm lines is uniform across the discharge gap at the initial of discharge and reaches as high as 10^(23)m^(-3).The excited species of He,OH,and H show different spatio-temporal behaviors from each other by the measurement of their emission intensities,which are discussed qualitatively in regard of their plasma kinetics.
文摘This paper reports that the optical emission spectroscopy （OES） is used to monitor the plasma during the deposition process of hydrogenated microcrystalline silicon films in a very high frequency plasma enhanced chemical vapour deposition system. The OES intensities （Sill^＊, H^＊ and H^＊β） are investigated by varying the deposition parameters. The result shows that the discharge power, silane concentrations and substrate temperature affect the OES intensities. When the discharge power at silane concentration of 4% increases, the OES intensities increase first and then are constant, the intensities increase with the discharge power monotonously at silane concentration of 6%. The SiH^＊ intensity increases with silane concentration, while the intensities of H^＊α and H^＊β increase first and then decrease. When the substrate temperature increases, the SiH^＊ intensity decreases and the intensities of H^＊α and H^＊β are constant. The correlation between the intensity ratio of IH^＊α/ISiH^＊ and the crystalline volume fraction （Xc） of films is confirmed.
基金supported by the National Basic Research Program of China 973 Program (No. 2009GB107004)the Fundamental Research Funds for the Central Universities of China (No. ZYGX2010J056)
文摘Optical emission spectroscopy and Langmuir Probe diagnostics were incorporated into the experiment, in which dust particles were formed in-situ by using reactive mixture gases （SiHa/C2H4/Ar） in a radio-frequency （RF） discharge plasma. The excitation temperature was first calculated by combining several optical emission spectra of argon lines and using a Boltzmann distribution to fit the experimental data, then the excitation temperature as functions of both gas pressure and RF power in SiH4/C2Ha/Ar discharges for different discharge conditions were obtained. Correspondingly, based on the measurement of the electron temperature by a Langmuir probe, the excitation temperature was compared with the electron temperature, and some discussions were presented. Finally the emission intensities of spectral lines of Si 390.6 ran, Si2＋ 380.6 nm and C＋ 426.7 nm were measured and presented as functions of pressure, RF power and flow rate of SiH4/C2H4.
