Light Source System Research Articles

Electro-optical characteristics of an innovative LED luminaire with an LED matrix cooling system based on heat pipes

Widespread use of energy-saving LED lighting systems powered by renewable energy sources, solar energy in particular, will contribute to the improvement of global ecology. One of the structural elements of such lighting systems is LED luminaire. The authors of this article perform a first ever experimental study of electro-optical characteristics of the basic version of a compact high-power LED luminaire for indoor use. The particular feature of this lighting device is that its cooling system for the LED light source is based on heat pipes and concentric cooling rings. Such design allows ensuring the required cooling efficiency of the LED matrix. The revealed trends in optical and electrical parameters during temperature stabilization indicate that the proposed cooling system is highly efficient in maintaining normal thermal conditions of LED light sources with a power of up to 140.7 W and a luminous flux of up to 15083 lm. The results on determining spatial distribution of luminous flux of these luminaires indicate that they may be used for lighting large rooms with high ceilings. Scaling the basic modular design version of the cooling system allows increasing the power of the LED light source up to 600 W.

Photo-Triggered Logic Circuits Assembled on Integrated Illuminants and Resonant Nanowires

High-performance photo-triggered electronic devices have already become an abiding target of optoelectronics. Current results, involving high-sensitivity phototransistors with the enhancement of material properties or the modification of electrical field, need an independent external light-source system. Nevertheless, few research studies inform of circuits in which the logic channel can be directly light controlled by a fully integrated photogate. In this paper, nanowire-based photon-effect transistors (PETs) combined with organic light-emitting diode (OLED) gates, and the photo-triggered nanowire circuits (PTNCs) are exhibited. The nanowire channels are manifested as high-quality optical cavities coupled by reflective electrodes for forming standing wave resonance. With the function of resonance, the nanowire channel under the illumination of the OLED gate can reach a high on/off ratio of ∼107, and under the different interconnected configuration of OLED gates, the functions of PETs can separately be realized as P-type and N-type of CMOS-like transistors. Then, a PTNC inverter that includes two nanowire channels with the respective OLED gates is operated utilizing electrical input voltage and logic opposite output signal. NAND and NOR gates as PTNC have also been demonstrated and indicate their corresponding outstanding arithmetic logic operation. PTNCs can effectively represent an innovative step toward multipurpose photonic circuits as to programmable logic components and photo-triggered computing.

(Plenary) Creating the Interface between the Universe and Data with Integrated Photonic Sensors

Integrated photonics is a particularly attractive option for building broadly useful sensor platforms. Here, the light source, sensing mechanism, and detection system are all in the same plane. As such, these sensors are small and simple enough that they could be incorporated into a cell phone. For the past five years, we have worked in partnership with the American Institute for Manufacturing Integrated Photonics (AIM Photonics) to establish designs and manufacturing strategies for photonic chemical and biological sensors. AIM is a public-private partnership established to develop U.S. manufacturing capability in photonics.

Preparation and photoelectric properties of Zn2SnO4-based composite nanomaterials

The zinc (Zn)-type compound zinc stannate (Zn2SnO4) is critical in the field of thin-film solar cells and photocatalysis. In this study, a new composite nanomaterial zinc stannate/tin (IV) oxide (SnO2) was synthesised through a high-temperature synthesis spray process. The electrochemical properties of the samples were tested. Besides, different ratios of zinc stannate/tin (IV) oxide nano-heterostructures were synthesised by using the ion exchange method, with zinc stannate nanocrystals as substrates. Also, their photocatalytic activities in a three-electrode system of simulated solar light sources were discussed. The photoelectric property of zinc stannate/tin (IV) oxide obtained from the solvothermal method was tested. The photocurrent of the obtained zinc stannate/tin (IV) oxide thin-film reached 2.6 μA, while the photocurrent of the zinc stannate thin film was only 0.13 μA. In the meantime, the fluorescence spectrum test proved that the recombination of zinc stannate and tin (IV) oxide reduced the recombination of photo-generated carriers. The photocatalytic test of zinc stannate/tin (IV) oxide obtained from the ion exchange method showed that given a 0.5 V reversible hydrogen electrode, the photocurrent of zinc stannate/tin (IV) oxide reached 0.62 mA/cm2. This indicator was 10 times the value of pure zinc stannate photocurrent under the same condition, which showed an increase in the photocatalytic capacity of zinc stannate. It proved that zinc stannate/tin (IV) oxide composite nanomaterials have better photoelectric performances and application prospects in the fields of solar cells and photocatalysis.

Evaluating the persistence of laundered semen stains on fabric using a forensic light source system, prostate-specific antigen Semiquant test and DNA recovery-profiling.

Semen stains on the clothes of victims of sexual assault can remain as evidence even after garments have been laundered. In this study, we aimed to investigate the effectiveness of commonly preferred methods to detect semen stains in two different fabric types that were laundered with different washing machine programmes and washing powders, and to obtain a DNA profile from the semen stains. For this purpose, a comprehensive study was performed on semen-stained underwear using three different methods for stain detection, confirmation and identification: a forensic light source (FLS) system, the prostate-specific antigen (PSA) test and DNA recovery profiling. With FLS applications, stronger fluorescence was achieved in wash protocols performed at a low temperature (30°C) on semen-stained cotton underwear. DNA recovery between 13.45 and 55.00 ng/µl was obtained by modifications in the DNA extraction step when the effect of temperature and washing powder on DNA recovery was evaluated, and these were enough for short tandem repeat (STR) typing in all samples. This study shows that when semen-stained underwear is washed after a month, some semen stains can be determined by FLS and PSA, and all stains can be identified by STR analyses.

Grating Design of a Hybrid Fresnel Lens for Collimating Nonaxial Double Light Source Systems

Grating Design of a Hybrid Fresnel Lens for Collimating Nonaxial Double Light Source Systems

立体化高空间照明均匀度LED植物光源的设计

立体化高空间照明均匀度LED植物光源的设计

多光源模块植物光源系统的设计

多光源模块植物光源系统的设计

二氧化硫检测仪光源系统的优化设计

二氧化硫检测仪光源系统的优化设计

The Application of High Efficiency and Low Noise Switching Power Supply in Fiber Optic Gyroscope

For high-precision fiber optic gyro systems, the efficiency and noise in the switching power source limits its application and also affects the system's light source and signal processing circuit, resulting in output errors. The interference mechanism of switching power supply ripple noise on super luminescent diode (SLD) light source and demodulation module in fiber optic gyro system is analyzed. A high-efficiency and low-noise switching power supply based on synchronous rectification is proposed. The power supply uses RC circuit to realize adjustable switching frequency. The push-pull isolation topology, LC filter and LDO regulator circuit are used to achieve constant voltage output with peak-to-peak ripple noise of less than 1mV. The conversion efficiency of the switching power supply is improved by 10%, which provides a high-quality power source for the high-precision fiber optic gyroscope. In the meanwhile, the switching power source for FOG is 541cm in size, which is beneficial to the miniaturization of inertial navigation system.

Design of 500 MHz RFQ linear accelerator for a compact neutron source, RANS-III

A compact neutron source using a particle accelerator is a promising tool for material analysis, infrastructural diagnostics, fissile material detection, and medical applications. For non-destructive, on-site inspection of the degradation of aged concrete and steel reinforcement it is essential to develop a light and compact neutron source system. To design a more compact RFQ linac for a transportable neutron source, we developed a 500 MHz RFQ linac.In this paper the design of a 500 MHz RFQ linac for a compact neutron source is described. First, using beam tracking simulation software, we designed the cell parameters of the 500 MHz RFQ linac, which can accelerate a proton beam from 30 keV to 2.49 MeV. Then, using three-dimensional electromagnetic simulation software and multiphysics simulation software, we optimized the cavity design of the 500 MHz RFQ linac, and investigated the thermal properties of the cavity with the cooling channels.

Camera calibration method in specific bands for the near-infrared dynamic navigator

The positional accuracy of a near-infrared (NIR) dynamic navigator is remarkably affected by two factors. One is the calibration accuracy of the navigator’s two NIR cameras, and the other is the accuracy of feature point extraction. The current lack of accurate calibration devices for NIR cameras limits further application. Therefore, in this study, an NIR camera calibration device was designed by placing the NIR light source and heat dissipation system at the back of a Halcon transparent glass template. Usage of camera calibration in a specific band and the gray centroid method based on elliptic boundary to extract feature points can further improve the accuracy of vision system calibration and measurement. Repeated tests and verifications showed that the reconstruction accuracy (

Optical endovascular imaging combining endoscopy, NBI and OCT, a feasibility study

Abstract For imaging of the vascular structure, angiography is state of the art. This can be done by contrast enhanced XRay, CT or MR imaging. But these modalities typically only show the blood flow and do not allow a depiction of the vasculature itself. To provide information about the vessel walls and plaques narrowing the blood flow, catheter based intra vascular ultrasound or vascular optical coherence tomography can be used. Optical endoscopic imaging is rarely used in vascular diagnosis. But endoscopic imaging can depict superficial inflammations or defects of the intima vessel layer and the real anatomical shape of the inner vasculature e.g. at bifurcations or aneurysms. Since OCT and endoscopic imaging both need a flushing to remove the blood for a short time, a combination of both modalities seems viable. For combining the two modalities, various background studies were performed including the selection of a feasible fibre endoscope, light source and camera system. A new pull-back and flushing device was designed and created for realizing the synchronous image acquisition using the two modalities. For calibration of the system and definition of the pullback and imaging parameters, first tests on artificial phantoms were performed. Then vascular and tissue models were imaged in a combined pullback mode after using the flush for complete blood removal. Endoscopic images were acquired in a video mode. The analysis of the images was done subjectively. As expected, the OCT provided structural information of the wall. The endoscopic images in combination with pullback appear blurry in video mode. The flushing liquid hinders the automatic focusing of the camera. Thus, smaller details could not be identified but bifurcations were visible. Even though the results were not good as expected, the study showed the potential of a bimodal system and addressed the issues faced in the initial implementation.

Effect of Arc Pressure on the Digging Process in Variable Polarity Plasma Arc Welding of A5052P Aluminum Alloy.

The keyhole digging process associated with variable polarity plasma arc (VPPA) welding remains unclear, resulting in poor control of welding stability. The VPPA pressure directly determines the dynamics of the keyhole and weld pool in the digging process. Here, through a high speed camera, high frequency pulsed diode laser light source and X-ray transmission imaging system, we reveal the potential physical phenomenon of a keyhole weld pool. The keyhole depth changes periodically corresponding to the polarity conversion period if the current is same in the electrode negative (EN) phase and electrode positive (EP) phase. There exist three distinct regimes of keyhole and weld pool behavior in the whole digging process, due to the arc pressure attenuation and energy accumulation effect. The pressure in the EP phase is smaller than that of the EN phase, causing the fluctuation of the weld pool free surface. Based on the influence mechanism of energy and momentum transaction, the arc pressure output is balanced by separately adjusting the current in each polarity. Finally, the keyhole fluctuation during the digging process is successfully reduced and welding stability is well controlled.

运动式太阳模拟器LED阵列光源及其准直光学系统设计

运动式太阳模拟器LED阵列光源及其准直光学系统设计

便携式光源、光功率计系统开发与设计

便携式光源、光功率计系统开发与设计

Research on High Brightness Light Source Equipment for Wind Tunnel Test

The experimental technology of high brightness light source was studied in sub-transonic supersonic wind tunnel. The elevation light source should be installed on the smooth wall of the tunnel, and the elevation camera should be installed in the safe area of the lower wall of the wind tunnel. The falling image of the missile model in the test is reflected into the elevation camera through a reflector mounted on a curved knife. The full trajectory images and aerodynamic parameters of projectiles of embedded weapons in aircraft can be obtained by the wind tunnel dual-view angle, high brightness light path system and six-degree-of-freedom image analysis system. The newly developed high brightness light source system makes the image clearer and the accuracy of model angle of attack identification less than 0.2 degrees, which is conducive to the analysis of model trajectory. The optical system is designed reasonably, so that the motion trajectory and six-degree-of-freedom data of the model can be obtained easily by using the dual-view technology. Wind tunnel tests under complex aerodynamic conditions of sub-transonic supersonic and multi-body interference have been completed, and all parameters have reached or surpassed the existing technical indicators, meeting the requirements of wind tunnel test research on ejection of embedded weapons in aircraft.

高照明均匀度倒置型LED植物光源系统的设计

高照明均匀度倒置型LED植物光源系统的设计

A Pt-free pristine monolithic carbon aerogel counter electrode for dye-sensitized solar cells: up to 20% under dim light illumination.

In this work, pristine carbon aerogels (CAs) were used as Pt-free counter electrodes (CEs) in dye-sensitized solar cells (DSSCs) by varying the molar ratio of their precursors. Pristine mesoporous CAs with controlled resorcinol (R)/formaldehyde (F) and resorcinol (R)/sodium carbonate (C) molar ratios were successfully prepared. The as-prepared CAs were synthesized via a polymeric sol-gel reaction and were labeled as CA-O, CA-Q, CA-F, CA-C, and CA-G. The DSSCs using the as-prepared CA-C CE gave the best power conversion efficiency (PCE, η), 9.08 ± 0.01%, among all the CA CEs. The CA-C CE is further applied to an indoor T5 light source system with an impressive η value of 20.1 ± 0.60% at 2.18 mW cm-2 (T5 lamp with 7000 lux). Moreover, the hardness of CA-C CE is 3.01 GPa (Brinell hardness test), which is comparable to that of the FTO/glass substrate. As a result, the CA-C CE shows great potential to replace traditional CEs based on the Pt/FTO/glass in DSSCs.

Null interferometric microscope for ICF-capsule surface-defect detection.

Isolated defects on the surface of the inertial confinement fusion (ICF) capsule reduce the probability of ignition. Here, to the best of our knowledge, we present the first null interferometric microscope (NIM) for direct and large-field surface defects detection on ICF capsules. The planar reference mirror in conventional interferometric microscopes is replaced by a spherical reference mirror to achieve null interference in the full field of view. Further, via the use of a short-coherence light source system, parasitic fringes are avoided. The feasibility of the NIM is verified via experiments on a 0.7mm diameter capsule. A 1mm diameter ICF capsule is also tested by the NIM to prove that the NIM has the ability to measure capsules with different diameters.