- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON) - Valparaiso, Chile (2019.11.13-2019.11.27)] 2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON) - Fourier-Bessel Shapes in Output Photocurrents and Frequency Chirping Effects from Laser Fields
摘要： Record low values in this material system of threshold current density, particularly at elevated temperature, are presented for InP quantum dot lasers. Lasers with Ga0 .5 8 In0 .4 2 P in the dot upper con?ning layer have the lowest threshold current densities, 138 A·cm?2 at 300 K, and 235 A·cm?2 at 350 K (77 °C) (2-mm lasers, uncoated facets). Gain-current density data suggests laser performance with an upper con?ning layer of Gax In1 ?xP with x = 0.54, 0.56 or 0.58 would be similar if not for the very low internal optical mode loss, αi of samples with x = 0.56 and 0.58. Gain measurements at ?xed inversion level suggest that increasing x content in Gax In1 ?xP increases gain at ?xed inversion level but samples with x = 0.54 also exhibit reduced recombination current density. The increasing recombination current density at elevated temperature due to thermal carrier spreading is signi?cantly reduced in samples with x = 0.56 and x = 0.58 but measurements at common operating points attribute this largely to the reduced αi for these samples and given the same αI , samples with x = 0.54, 0.56 and 0.58 would all bene?t from reduced effects due to thermal carrier spreading compared to x = 0.52.
关键词： Quantum dot devices,InP self-assembled quantum dots,semiconductor laser,short wavelength lasers,threshold current density,temperature sensitivity
更新于2025-09-23 15:21:01
-
Multistimuli-responsive small-molecule compound with aggregation-induced emission enhancement characteristics: preparation, properties and applications
摘要： A novel multifunction luminescent small-molecule compound with hydrophilic chains was successfully designed and synthesized, which exhibited aggregation-induced emission enhancement (AIEE) characteristics. Even more interesting, it exhibited responsive behavior to temperature, pH and UV irradiation. In aqueous solution, its luminescence intensity showed temperature sensitivity. Initially, its luminescence intensity decreased slightly with an increase in temperature, which was enhanced greatly when the temperature increased to its lower critical solution temperature (LCST). With a further increase in temperature, there was a significant decline in its luminescence intensity. Additionally, it showed different pH and UV irradiation responsive behaviors in water and THF solution. In THF solution, its luminescence intensity was enhanced greatly with the addition of alkali, but it decreased with an increase in UV irradiation time. In aqueous solution, its luminescence intensity was enhanced slightly and its LCST decreased first and then increased with the addition of alkali. However, its luminescence intensity increased with an increase in UV irradiation time. The prepared small-molecule compound could also be used as a rewritable material with solid alkali or alkali solution used as ink and ordinary paper adsorbed with our prepared small-molecule compound used as rewritable paper.
关键词： small-molecule compound,rewritable material,temperature sensitivity,pH responsive,multistimuli-responsive,aggregation-induced emission enhancement,UV irradiation responsive
更新于2025-09-19 17:15:36
-
Enhanced sensitivity of distributed-temperature sensor with Al-coated fiber based on OFDR
摘要： In this paper, we present a distributed-optical fiber temperature sensor with enhanced sensitivity with Al coating using the Rayleigh backscattering (RBS) spectrum shift measured via optical frequency-domain reflectometry (OFDR). The Al-coated sensing fiber having a larger thermal expansion coefficient than that of silica produces a strain-coupled shift in the RBS under an increase in temperature. This effect leads to an enhanced temperature sensitivity of the distributed measurement scheme. In order to analyze the principle of temperature sensitivity enhancement, a simple analysis was performed by considering the fiber directional strain and force equilibrium between the optical fiber and Al-coated layer. Our results revealed that the temperature sensitivity achieved with the Al-coated fiber in OFDR was ～56% higher relative to that of a single-mode fiber.
关键词： Al-coated fiber,Distributed sensor,Thermal expansion,Optical frequency-domain reflectometry,Temperature sensitivity
更新于2025-09-19 17:15:36
-
The effect of the recombination mechanisms location on the temperature sensitivity of thin-film photovoltaic cells
摘要： Thin film solar cells temperature sensitivity and impact of the main recombination mechanism location are investigated in this paper. The main mechanisms in bulk and at the heterojunction interface are discriminated. Using a 1D simulation software, “Solar Cell Capacitance Simulator” (SCAPS), we observed a higher temperature coefficient of open circuit voltage (Voc) for cells with main recombination centers at the interface than the one with main recombination centers in volume. Furthermore, an LTSpice module model is used to visualize the effects of the recombination centers’ location on the performance ratios of the modules. The results show more degradation for the ratios performance of cells with the main recombination mechanisms at the interface than those in volume.
关键词： recombination mechanisms,thin film cells,ratios performance,Temperature sensitivity
更新于2025-09-19 17:13:59
-
[IEEE 2019 IEEE Pulsed Power & Plasma Science (PPPS) - Orlando, FL, USA (2019.6.23-2019.6.29)] 2019 IEEE Pulsed Power & Plasma Science (PPPS) - Auto-collimation and monitoring of laser beam in high power electron-pumped KrF laser facility
摘要： Record low values in this material system of threshold current density, particularly at elevated temperature, are presented for InP quantum dot lasers. Lasers with Ga0 .5 8 In0 .4 2 P in the dot upper con?ning layer have the lowest threshold current densities, 138 A·cm?2 at 300 K, and 235 A·cm?2 at 350 K (77 °C) (2-mm lasers, uncoated facets). Gain-current density data suggests laser performance with an upper con?ning layer of Gax In1 ?xP with x = 0.54, 0.56 or 0.58 would be similar if not for the very low internal optical mode loss, αi of samples with x = 0.56 and 0.58. Gain measurements at ?xed inversion level suggest that increasing x content in Gax In1 ?xP increases gain at ?xed inversion level but samples with x = 0.54 also exhibit reduced recombination current density. The increasing recombination current density at elevated temperature due to thermal carrier spreading is signi?cantly reduced in samples with x = 0.56 and x = 0.58 but measurements at common operating points attribute this largely to the reduced αi for these samples and given the same αI , samples with x = 0.54, 0.56 and 0.58 would all bene?t from reduced effects due to thermal carrier spreading compared to x = 0.52.
关键词： Quantum dot devices,InP self-assembled quantum dots,semiconductor laser,short wavelength lasers,threshold current density,temperature sensitivity
更新于2025-09-19 17:13:59
-
[IEEE 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Guangzhou, China (2019.5.19-2019.5.22)] 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - A Circularly Polarized Waveguide Slot Antenna for Random Array Application
摘要： Record low values in this material system of threshold current density, particularly at elevated temperature, are presented for InP quantum dot lasers. Lasers with Ga0.58In0.42P in the dot upper con?ning layer have the lowest threshold current densities, 138 A·cm?2 at 300 K, and 235 A·cm?2 at 350 K (77 °C) (2-mm lasers, uncoated facets). Gain-current density data suggests laser performance with an upper con?ning layer of GaxIn1?xP with x = 0.54, 0.56 or 0.58 would be similar if not for the very low internal optical mode loss, αi of samples with x = 0.56 and 0.58. Gain measurements at ?xed inversion level suggest that increasing x content in GaxIn1?xP increases gain at ?xed inversion level but samples with x = 0.54 also exhibit reduced recombination current density. The increasing recombination current density at elevated temperature due to thermal carrier spreading is signi?cantly reduced in samples with x = 0.56 and x = 0.58 but measurements at common operating points attribute this largely to the reduced αi for these samples and given the same αI, samples with x = 0.54, 0.56 and 0.58 would all bene?t from reduced effects due to thermal carrier spreading compared to x = 0.52.
关键词： Quantum dot devices,InP self-assembled quantum dots,semiconductor laser,short wavelength lasers,threshold current density,temperature sensitivity
更新于2025-09-19 17:13:59
-
Sensing characteristics of long period grating by writing directly in SMF-28 based on 800?nm femtosecond laser pulses
摘要： A long period grating is fabricated in standard SMF-28 ?bers without hydrogen loading by adopting point-by-point direct writing based on femtosecond laser pulses with 800 nm wavelength and 100 fs pulse width. Its sensing characteristics is investigated and the sensing sensitivities to temperature, external refractive index (RI) and strain are systematically examined as well. The experimental results show that the sensing sensitivity of the long period grating to temperature, RI and strain is about 124 pm/°C with a linearity of 0.989 within temperature ranging from 20 °C to 800 °C, ?582.5 nm/RIU (refractive index unit) with a linearity of 0.998 in the RI ranging from 1.342 to 1.380, and ?9.45 × 10-4 dB/με with a linearity of 0.98 in the strain ranging from 0 to 2925 με, respectively. The high sensitivity of prepared LPG will have potential application values in sensing measurement of multi-parameters and in the ?eld of high temperature and harsh environments detection.
关键词： Refractive index (RI),Long Period Gratings (LPGs),Femtosecond laser,Strain sensing,Temperature sensitivity
更新于2025-09-12 10:27:22
-
Temperature sensitivity investigation of tapered plastic optical fiber-Mach Zehnder interferometer for sensor application
摘要： Mach Zehnder interferometer (MZI) based on plastic optical fiber (POF) is interesting due to its robustness and simple fabrication. In this work, MZI-POF was designed and its sensitivity to temperature change was characterized to investigate its performance for sensor application. The MZI-POF was fabricated by forming two tapers at several distance by simple heat-pull method. The spectra was investigated by launching white light emitting diode (LED) and the output were observed using VIS-NIR spectrometer. It is shown that the wavelength of spectrum peak and spectrum dip were shifted compared to that of un-tapered POF which indicates that the structure serves well as MZI. Sensor sensitivity to temperature was determined by measuring the spectrum for various temperature which was varied from 40oC to 80oC with increment of 5oC. The result showed that the sensor sensitivity is 0.0693nm/oC in terms of peak measurement and 0.0487nm/oC for dip measurement. Therefore, MZI-POF is a potential candidate for temperature sensor.
关键词： Mach Zehnder interferometer,temperature sensitivity,sensor application,plastic optical fiber
更新于2025-09-11 14:15:04
-
Facile synthesis of poly N-isopropylacrylamide/acrylamide-quantum dots hybrid hydrogels and their fluorescence temperature sensitive behaviors
摘要： Poly (N-isopropylacrylamide) (PNIPAM) is an intelligent hydrogel which exhibits volume transition in response to temperature change. This work reports the PNIPAM/AM-QDs hybrid hydrogels, in which N-isopropylacrylamide, acrylamide as monomers and CdTe/CdS quantum dots (QDs) as filler, are prepared by glow discharge electrolysis plasma (GDEP). The hydrogels are investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), FTIR spectra, differential scanning calorimetry (DSC) and PL spectra, as well as the swelling rate, temperature sensitivity and fluorescence reversibility. The results show that the PNIPAM hydrogels and QDs are cross-linked by coordination bond, and the QDs are well dispersed and combined firmly in the networks of the hydrogels. The phase transition temperature of PNIPAM/AM-QDs hybrid hydrogels is 32.5°C. The fluorescence intensity of hydrogels is 1490 a.u. and 20 a.u. at 20 and 40°C, respectively. Furthermore, the luminescence intensity of hydrogels is almost not weakened after five heating-cooling cycles, which should be used as a temperature-controlled light switch.
关键词： hybrid hydrogel,N-isopropylacrylamide,temperature sensitivity,CdTe/CdS,fluorescence property,glow discharge electrolysis plasma
更新于2025-09-11 14:15:04
-
Studies on Temperature and Strain Sensitivities of a Few-mode Critical Wavelength Fiber Optic Sensor
摘要： This paper studied the relationship between the temperature/strain wavelength sensitivity of a fiber optic in-line Mach-Zehnder Interferometer (MZI) sensor and the wavelength separation of the measured wavelength to the critical wavelength (CWL) in a CWL-existed interference spectrum formed by interference between LP01 and LP02 modes. The in-line MZI fiber optic sensor has been constructed by splicing a section of specially designed few-mode fiber (FMF), which support LP01 and LP02 modes propagating in the fiber, between two pieces of single mode fiber. The propagation constant difference, Δβ, between the LP01 and LP02 modes, changes non-monotonously with wavelength and reaches a maximum at the CWL. As a result, in sensor operation, peaks on the different sides of the CWL then shift in opposite directions, and the associated temperature/strain sensitivities increase significantly when the measured wavelength points become close to the CWL, from both sides of the CWL. A theoretical analysis carried out has predicted that with this temperature/strain sensor approach, the temperature/strain wavelength sensitivities are governed by the wavelength difference between the measured wavelength and the CWL. This conclusion was seen to agree well with the experimental results obtained. Combining the wavelength shifts of the peaks and the CWL in the transmission spectrum of the SFS structure, this study has shown that this approach forms the basis of effective designs of high sensitivity sensors for multi-parameter detection and offering a large measurement range to satisfy the requirements needed for better industrial measurements.
关键词： few mode fiber,temperature sensitivity,In-line Mach-Zehnder interferometer,strain sensitivity,critical wavelength
更新于2025-09-09 09:28:46