Zhang X.,Precision Information |
He H.,Precision Information |
Fan J.,Precision Information |
Gu C.,Precision Information |
And 5 more authors.
Optics Express | Year: 2013
Nonlinearity of semiconductor nanowires makes them potential frequency converters in nanoscale optoelectronics. Here we demonstrate that sum frequency generation signals can be acquired from GaAs nanowires when excited by a femtosecond laser at 1048 nm and a tunable optical parametric oscillator ranging from 1416 nm to 1770 nm. The SFG intensity is insensitive to the polarization but quite sensitive to the temporal overlap of incident lasers pulses. It is shown that they can work for pulsewidth measurement of femtosecond lasers in the near infrared band. Our results suggest GaAs NWs to be excellent optical nonlinear mixers in nanoscale optoelectronics. © 2013 Optical Society of America.
Wang Y.,Precision Information |
He H.,Precision Information |
He H.,Shanghai JiaoTong University |
Li S.,Nankai University |
And 6 more authors.
Scientific Reports | Year: 2014
Controllable gene expression is always a challenge and of great significance to biomedical research and clinical applications. Recently, various approaches based on extra-engineered light-sensitive proteins have been developed to provide optogenetic actuators for gene expression. Complicated biomedical techniques including exogenous genes engineering, transfection, and material delivery are needed. Here we present an all-optical method to regulate gene expression in targeted cells. Intrinsic or exogenous genes can be activated by a Ca2+-sensitive transcription factor nuclear factor of activated T cells (NFAT) driven by a short flash of femtosecond-laser irradiation. When applied to mesenchymal stem cells, expression of a differentiation regulator Osterix can be activated by this method to potentially induce differentiation of them. A laser-induced "Ca2+-comb" (LiCCo) by multi-time laser exposure is further developed to enhance gene expression efficiency. This noninvasive method hence provides an encouraging advance of gene expression regulation, with promising potential of applying in cell biology and stem-cell science.
Lamb D.W.,Precision Information |
Schneider D.A.,Precision Information |
Trotter M.G.,Precision Information |
Schaefer M.T.,Precision Information |
Yule I.J.,Massey University
Computers and Electronics in Agriculture | Year: 2011
Recently reported testing of active, optical crop sensors in low-level aircraft have demonstrated a new class of airborne sensing system that can be deployed under any ambient illumination conditions, including at night. A second-generation, high-powered, light-emitting diode system has been assembled and tested over a 80ha field of wheat (Triticum aestevum) by mapping the normalised difference vegetation index (NDVI) at altitudes ranging from 15 to 45 m above the canopy; significantly higher altitudes than existing systems. Comparisons with a detailed on-ground NDVI survey indicated the aerial sensor values were highly correlated to the on-ground sensor (0.79
Lei L.,Engineering School of Information Technology and Communication |
Guang-Jun R.,Engineering School of Information Technology and Communication |
Bei L.,Engineering School of Information Technology and Communication |
Jian-Quan Y.,Precision Information
Journal of Optoelectronics and Advanced Materials | Year: 2011
Using the temperature sensitivity of refractive index of Liquid Crystal (LC), a new type of LC photonic crystal fiber (PCF) terahertz waveguide by temperature modulation is designed which is based on that the core of PCF is filled with nematic LC 5CB. The change of characteristics of modes of PCF with temperature under the conditions of different core radius is simulated. It is shown that there is no endless single mode. The waveguide dispersion of terahertz waveguide under the different temperature is simulated. It is shown that, the dispersion constant decreases with temperature increasing and the ultra-flattened dispersion is implemented.
Hao C.J.,Precision Information |
Lu Y.,Precision Information |
Wang M.T.,Precision Information |
Wu B.Q.,Precision Information |
And 2 more authors.
IEEE Photonics Journal | Year: 2013
We propose a surface plasmon resonance (SPR) refractive index (RI) sensor based on an active Yb3+-doped photonic crystal fiber (PCF) in this paper. With the proposed sensor, using the pump light at 976 nm can produce laser at 1060 nm. In addition, the sensitivity can be influenced obviously by a bit change of the refraction index of analyte in the air holes to achieve the intra-cavity fiber sensing. It is found that not only the different air-filling ratios but also the different analyte RIs of na > 1:45 or n a < have different effects on the output power and confinement loss, and lead to different trends. The intra-cavity PCF sensing system has great practical value and significance for their advantages of compact structure and high sensitivity. © 2009-2012 IEEE.
Lamb D.W.,Precision Information |
Schneider D.A.,Precision Information |
Stanley J.N.,Precision Information
Precision Agriculture | Year: 2014
An integrated active optical, and passive thermal infrared sensing system was deployed on a low-level aircraft (50 m AGL) to record and map the simple ratio (SR) index and canopy temperature of a 230 ha cotton field. The SR map was found to closely resemble that created by a RapidEye satellite image, and the canopy temperature map yielded values consistent with on-ground measurements. The fact that both the SR and temperature measurements were spatially coincident facilitated the rapid and convenient generation of a direct correlation plot between the two parameters. The scatterplot exhibited the typical reflectance index-temperature profile generated by previous workers using complex analytical techniques and satellite imagery. This sensor offers a convenient and viable alternative to other forms of optical and thermal remote sensing for those interested in plant and soil moisture investigations using the ‘reflectance index-temperature’ space concept. © Springer Science+Business Media New York 2014.
Kohl J.,Friedrich - Alexander - University, Erlangen - Nuremberg |
Fey D.,Friedrich - Alexander - University, Erlangen - Nuremberg |
Basig J.,Precision Information
2015 International Conference on Industrial Instrumentation and Control, ICIC 2015 | Year: 2015
The advancing automation of the industrial production requires faster and more efficient programmable logic controllers. Today's controller architectures based on specialized processors to execute the STL application are at their limits. For any further improvement the architecture of these processors needs to evolve from single core in order execution to a multicore out of order architecture. This step can not occur without additions to the PLC's instruction set. Therefore a PLC processor instruction set simulation is required that allows a quick evaluation of the effectiveness and efficiency of instruction set changes as well as changes to the processor's architecture. Current architecture description languages (ADL) allow the fast modeling of these changes with enough flexibility for the planned improvements and provide fast simulation speed. This work presents for the first time an instruction set simulation environment for STL compatible PLC processors using the ADL ArchC as a base for further research. © 2015 IEEE.
Sharan G.,Precision Information
c2013 IEEE Global Humanitarian Technology Conference: South Asia Satellite, GHTC-SAS 2013 | Year: 2013
This paper describes the development of technology to harvest (condense and collect) dew water for use of people living in coastal area of Gujarat province, north-west India. Potable water is severely scarce in the area, such that extra supply of even tens of liters a day could add to water security of the households. A R&D program was initiated in the year 2001-02, after it was noticed that dew occurred more frequently and in larger quantity here than inlands. Dew water is extracted from air using condensers made of special plastic film which cool rapidly at night by radiating heat to atmosphere. Dew condensing efficiency of the plastic film appears to be comparable to blades of grass, natural vegetation. A four year R&D program led to design of large working systems after testing of prototypes and pilot units. Large dew harvest systems have been erected on roofs (condenser-on-roof), open ground (condenser-on-ground). Technology is simple, uses material available in the area and is amenable to do-it-yourself procedure. © 2013 IEEE.
PubMed | Precision Photonics Corp. and Precision Information
Type: Journal Article | Journal: Biomedical optics express | Year: 2015
We present detailed measurement results of optical attenuations thermal coefficients (referenced to the temperature of the skin surface) in different depth regions of in vivo human forearm skins using optical coherence tomography (OCT). We first design a temperature control module with an integrated optical probe to precisely control the surface temperature of a section of human skin. We propose a method of using the correlation map to identify regions in the skin having strong correlations with the surface temperature of the skin and find that the attenuation coefficient in these regions closely follows the variation of the surface temperature without any hysteresis. We observe a negative thermal coefficient of attenuation in the epidermis. While in dermis, the slope signs of the thermal coefficient of attenuation are different at different depth regions for a particular subject, however, the depth regions with a positive (or negative) slope are different in different subjects. We further find that the magnitude of the thermal coefficient of attenuation coefficient is greater in epidermis than in dermis. We believe the knowledge of such thermal properties of skins is important for several noninvasive diagnostic applications, such as OCT glucose monitoring, and the method demonstrated in this paper is effective in studying the optical and biological properties in different regions of skin.