Session Index

We propose CG-ASPL design to manipulate particle at a distance far away from the structure surface. The optical properties and trapping performances of CG-ASPL are simulated and analyzed. A particle of 1 μm diameter can be trapped in the far-field region (1.3λ) with low power illumination of 4 mW.

 

When the size of the micro light-emitting diode (micro-LED) becomes smaller, surface patterning is a way to improve the light extraction efficiency (LEE). We propose a method of adding microstructures on the surface of 10μm x 10μm micro-LED, analyzing LEE when changing the pitch and shape of structures. With a wavelength of 460 nm in 2D modules, optimized LEE with microstructures pitch of 760 nm. Compared to the micro-LED without microstructures by adding T-shaped and cylindrical microstructures, the LEE is increased by 10.3% and 11.3% in the 2D module, and 10.2% and 11.0% in the 3D module.

 

The frequency-resolved optical gating (FROG) is a well-known technique in ultrashort pulse measurement. However, the phase retrieval is time-consuming due to the iterative procedure. In this paper we demonstrate a fast and direct optical dispersion algorithm, which can directly determine the group delay dispersion (GDD) from single FROG trace, the computation time is 13 times faster than standard principal component generalized projection algorithm (PCGPA). We also combined the direct phase retrieval FROG with the PI controller, prism-based compressor to achieve automatic compensation system to multiphoton excitation fluorescent microscopy (MPEFM), the reconstructed image intensity can be elevated up to 1.6 times.

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The state-space dynamic model of a tracked robot in orchard has been identified with more than 50% estimated fitting, and then utilized in the model predictive control (MPC) process. The MPC with the model can precisely follow the reference paths according to suitable prediction and control horizons under multivariable constraints. The inputs of system identification are the different white noises of left and right tracked speed. We use Intel D435i depth camera with ORB-SLAM on Robot Operating System (ROS) to provide the localization information as the outputs. From the experimental result, system identification with MPC can follow the path correctly.

 

Fungus gnats cause significant damage and economic loss to mushroom plantations. In their young larvae stage, they feed rampantly on the mycelium of the mushrooms, rendering them useless for trade and human consumption. As an alternative to inconvenient and time consuming physical pest control methods and chemical pesticide overuse, we utilize frequency modulated UV-A light trap (365nm) to attract the fungus gnats to a small spot area, and then employ quick laser scanning to eliminate the pests in the area efficiently.

 

We present a mid-field model for a UVC LED by comparison of the 2-D irradiance pattern. Because of UVC light, we propose using fluorescent film which absorbs UV-C light and re-emits visible light so that the 2-D irradiance light pattern could be captured by a CCD or CMOS sensor, and then we compare with the corresponding simulation in mid-field distance.

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Aberrations generated as the light passed through optical components and specimen. Based on the proposed identification algorithm, we constructed the first and second order aberration shape of Zernike polynomials with electrostatic membrane deformable mirror (DM). Due to the coupling effect of the DM itself, we then applied PI closed loop controller for more precisely converging to separately shape of the Zernike polynomial. The identified model can be implemented for more accurate adaptive optics correction and practical application such as auto-focusing based on aberration manipulation technique.

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This study is to measure and compare the power distribution in spherical and aspherical tilted prescription spectacle lenses at different tilt angles. The results show that the effective power change along the tilt direction is less in the aspherical tilted lenses than in the spherical tilted lenses.

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An optical see-through (OST) head-mounted display (HMD) is based on a dihedral corner reflector array (DCRA) to give a wide field of view (FOV). A simulation modes combining the HMD lens, DCRA and eye model show that the eye can receive the display information in the wide FOV.

 

New conceptual lens modules which can predict the variations of primary chromatic aberrations and secondary spectrum for real thick optical lenses are proposed. They are capable of studying the chromatic aberration behaviors of conceptual lenses without their detailed structures. As a comparison, they also provide accurate results than some commercial optical software.

 

This research puts forward four common membrane stack formulas and finds a relatively better membrane stack formula applied to the dual narrow-band-pass filters. We found that the Air/(LH)M L 2H L (HL)M/Sub membrane stack formula compared to the other three membrane stack formulas not only has a relatively better filtering effect on the cut-off wavelength but also at 532.5nm full width at half maximum(FWHM) of 21nm, the average transmittance is 92.97%, and 620nm FWHM 40.5nm, the average transmittance is 97.17%.


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This study proposes a method of detecting air pollution using hyperspectral imaging technology of visible light, near-infrared, and far-infrared. By assigning hyperspectral information to the images of monocular, near-infrared, and thermal imaging, principal component analysis is performed on the hyperspectral images. Beer-Lambert law and multivariate regression analysis are used to calculate the PM2.5 and PM10 concentrations which are compared with the corresponding PM2.5 and PM10 concentrations from the Taiwan Environmental Protection Agency to evaluate the accuracy of this method. This study reveals that the accuracy in the visible light band is higher than the Near-Infrared and Far-Infrared bands.

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In this study, we use LightTools to build a 5 x 5 Micro-LED array model with the Distributed Bragg Reflector (DBR) optical material created by RSoft. Use DBR to suppress the intensity of the active light, so that the light intensity from the side to achieve high uniformity of the light source module. Through the Reinforcement Learning (RL) to find the best solution for illuminance uniformity.

 

The path following and obstacle avoidance of a field tracked vehicle is conducted by using the model predict control (MPC) with the controller (agent) trained by deep deterministic policy gradient (DDPG). The MPC forces the vehicle to follow the global reference path and the DDPG agent generates a new local path to avoid obstacles.
Reinforcement learning has been successfully applied to various tasks, but still there some problems due to low sample efficiency and inability to deal with large time delay. Therefore, our work is combined the MPC with the DDPG.

 

One kind of new endoscope introduced here, it consists of a new type sensor and a new optical system which can construct the three dimension model of a baglike organ.

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In this article, we establish an optical neural network to achieve a NAND gate with supervised learning method. The optimized bit error rate is 0.2495 as well as the normalized root mean square error is 0.65. Thus, through our result, our design could be a potential photonic device.

 

This work is to explore the nine-layer notch filter (SiO2/Nb2O5) with the center wavelength of 480 nm deposited by electron gun evaporation technology, and using the dual substrate technology to measure the coefficient of thermal expansion (CTE), biaxial modulus and thermal stress changes of the thin film.

 

A novel open-cavity fiber Fabry–Pérot interferometers (FPIs) formed by splicing two hollow-core fibers with a large offset is connected with a sealed-cavity fiber FPI in parallel to induce the Vernier effect for gas sensing. Four times higher gas pressure sensitivity of -128 pm/psi can be obtained.

 

Terahertz (THz) telecentric f-theta scanning lens plays an important role in the THz hyperspectral microscopy system. Beam scanning using telecentric f-theta lens provides uniform spot size, linear displacement, and normal incidence angle at the focal plane. In this work, we design a telecentric f-theta lens with superior performance on distortion (<0.012%). We are competent to fabricate our scanning lenses by using CNC technology. We observe approximately 4mm spot size and a broadband image from 0.4 to 1.0 THz. As a result, our design can resolve different diameters circular patterns with resolution better than 5mm.

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Autocorrelator is widely used in measuring ultrashort pulse. Conventionally, an autocorrelator collocates with an expensive BBO crystal. Based on the two and three photon absorption property of light-emitting diodes (LEDs), we can replace the crystals with very low-cost LEDs. The two-photon absorption (TPA) and three-photon absorption (3PA) of LED are simulated based on the two-band model and verified with experiments. The interferometric autocorrelation is measured by using red LED and get background-signal ratio equals to 1:8.

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A periscope zoom lens depth depends either on the prism thickness or the maximum aperture of the zoom lens in the Y-direction. To reduce the periscope zoom lens depth to 7 mm for Mobile Phone device and use a 5 megapixel sensor as 16:9 aspect ratio sensor with rectangular aperture.




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We present an optical measuring system for the focal length of optical lenses. Four different lenses were tested by the proposal method. The measuring ranges of focal length were 16 to 100 mm. The results showed that difference value of the focal lengths was less than 0.5 mm.

 

In this study, a novel “coplanar detection type grating interferometer” is proposed. It adopts “coplanar detection” as the core technique and combines with the techniques of heterodyne interferometry, grating interferometer and double-diffraction optical configuration, which makes the proposed system form multiple detection configurations on the same detection surface and have excellent measurement performance with high resolution and high stability.

 

In this study, the heliconical liquid crystal (LC) structures are adopted to make an electrically tunable broadband color filter; moreover, the trends of color variations are also successfully demonstrated through the approach of Jones Calculus, and to a large extent, the simulated results are coincident with the experimental ones.

 

This study demonstrates the way to detect polarization state of a polarized light with unknown polarization immediately by using an axially symmetrical dichroic dyes-doped liquid crystals (ASDDdLCs). A charge coupled device (CCD) records an image of a polarized light after passing through the ASDDdLCs. A program is used to analyze the images recoded by the CCD to immediately analyze its polarization state. The method has potential to be applied in various optical fields.

 

We proposed a design method to simulate a MEMS LiDAR system. Combining a MEMS mirror and a wide-angle lens into the system, small-volume and large field-of-view (FOV) LiDAR systems can be realized. The FOV of our LiDAR system is 104 degrees and the maximum error is less than 2%. In order to experimentally demonstrate the small-volume MEMS scanning LiDAR, a modular laser rangefinder is used with a MEMS mirror. Finally, the scanned data is converted into a 3D point cloud image by an image processing program, and the generated image proves the complete function of the proposed LiDAR.

 

We investigate the focusing efficiency and focal length dependence of a near infrared region metalens for a broadband design. First, we design a 1550 nm working wavelength metalens, then we extend working wavelength from 1500 nm to 1600 nm by particle swarm optimization (PSO) method .Finally, it is found that the working stage of the 1550nm metalens will cause the focal length to drop due to the increasing wavelength, our achromatic metalens can effectively reduce the displacement of the focal length.

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In this study, a novel linear encoder based on common-path design is proposed for displacement measurement. The proposed technique combines the advantages of grating interferometry and common-path, which makes the system not only can provide accurate displacement information but also have excellent stability. It can be seen from the experimental results, the measurement resolution and repeatability can reach 3 nm and 3 nm, while the stability is about 3.9 nm within 10 minutes, respectively.

 

Thin films were deposited on a large substrate holder with a diameter of 275 mm, which was divided into five segments. Thickness uniformity of five different segments is analyzed. The experimental results show that film thickness uniformity is 0.36% for Ta2O5, 0.38% for SiO2, and 0.15% for Nb2O5 thin films.

 

We demonstrated a polarization independent liquid crystal phase modulation based on the
orthogonal nematic LC mode wherein the optics axes of nematic liquid crystal molecules are
set orthogonally to adjacent sub-domains for the first time. A polarizer-free LC micro-lens is
demonstrated. The impact is for ophthalmic lenses and augmented reality.

 

A varifocal AR system is demonstrated adopting electrically tunable liquid crystal (LC) plane-parallel plates to solve vergence-accommodation conflict problem. In experiments, the projected virtual image can be adjusted from 1.4 m to 2.1 m away from the AR system while the thickness of LC plane-parallel plates < 3mm.

 

In general optical system, aberration is a common phenomenon that degrades the system performance. We use Zernike polynomials to describe aberrations. The low order eight Zernike modes are used as the fitting target. Based on the identification process, the membrane deformable mirror (DM) can generate the corresponding surface shape of the desired Zernike mode. In order to make the identification more accurate, we use PI controller to find the best combination of the identified voltage maps that drive the DM to have much better shape for individual Zernike modes.

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With the proposed membrane deformable mirror (DM) identification process, we can obtain the voltage maps of DM for generating individual first order Zernike polynomial. In this manner, we can design 8 separate proportional integral (PI) controllers to eliminate the aberrations rapidly and simplify the controller complexity. The experimental results show that we can compensate the static disturbance and the dynamic disturbance efficiently.

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A novel scheme using three-dimensional (3D) coupling structure to build a laser diode (LD) module is proposed, which utilizes the fiber’s angle space more completely. Compared with the traditional 2D configuration, the number of LD is increased by 15, and the efficiency over 90% efficiency can be still obtained.

 

A mosquito collecting component that can be externally attached to the air inlet of the
LED mosquito trapping system has been developed to optimize the efficiency of the mosquito
trapping lamp and increase the mosquito trapping capacity. Use 3D CAD software Soildworks to
build the system module, and use flow simulation to simulate thewind field. Import the module
into Tracepro for optical simulation, and observe the light field changes on the light pattern. Finally,
the module is used to actually measure and capture mosquitoes. After obtaining the data, the best
mosquito-trapping efficiency can be optimized.


 

The surface morphology and residual stress measurement of multilayered notch filters deposited on a 12-inch wafer was presented. A homemade projected fringe reflectometer was developed. Experimental results show that the surface warpage decreases from 27.66 μm to 9.7 μm. The residual stress of the multilayered notch filter was 0.21 GPa.

 

A green 2×2 micro-LED array with nanostructured grating patterns was enclosed in a TO-can with an SMA connector, grown on a semi-polar (20-21)-oriented GaN buffered layer on a (22-43)-oriented sapphire substrate. Supported bit-loaded DMT algorithms for very high-speed data transmission beyond 5 Gbit/s.

 

The AR eyeglasses are designed for 20/20 vision. However, human eyes differ. In this paper, a near-eye display system with electrically vision correction is demonstrated. The tunable range of the liquid crystal lens is around 4.5 Diopter with aperture size of 20 mm. The voltage is less than 20 Vrms.

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We demonstrate an achromatic, tunable polarization rotator (PR). By applying an electric field to control the liquid crystal, it continuously rotates up to 90° in an adiabatic and nondispersive manner. This mechanism can be used for single-path ultrawideband with complex vector fields in polarized light.

 

In the past, a two-dimensional aperture diffraction of light in the non-paraxial region could only be studied using the Huygens integral without functional forms. This work presents a special case—a one dimension slit where the functional form can be obtained. Three interesting spectral effects are described: spectral switches, multi-level data transmission, and optical wavelength ruler.

 

In this work, we study the timbres of Apoyando and Tirando for the classical guitars, which excite mainly the strings perpendicularly and parallel to the soundboard, respectively, by using laser displacement sensor. The natural frequency of the guitar body and the pitch of the strings with overtones can be observed in the spectra. The results show that the low-pitch natural frequency and the high-pitch overtones are stronger when the strings are plucked by Apoyando and Tirando, respectively inducing the different timbres. With this effect, the guitarists can deliver the warm or joyful feeling during the performance.

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Recently, MEMS scanners driven by the electrostatic actuation mechanism are increasingly being used in optical coherence tomography applications because of the low operating power, fabrication friendliness, fast response and lowest power consumption. However, most MEMS scanners driven by electrostatic actuation commercially available nowadays encounter scanning stability issues because of the open-loop driving mode. In this study, we have developed a swept-source OCT(SS-OCT) system to investigate the scanning stability of two different MEMS scanners which was operated in open-loop and close-loop driving mode individually. Repetitive cross-sectional OCT images of the fixed pattern target were acquired with a different scanning speed.

 

Historically, the periscope is the surveying subsystem of an indigenous submarine to observe objects above the sea while the submarine remains submerged. This paper reports the specification of a periscope in the past and analyzed the current system and a preliminary modeling result will also be evaluated.

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A gradient-intensity axial beam with properties of a narrow lateral spot and the gradient intensity along the optical axis is applied to the confocal profilometer for the surface-profile inspection. The experimental implementation of the gradient-intensity axial beam of pseudo Bessel beams is carried out and compared with the theoretical results.

 

We demonstrated the capability of 25 Hz vibration detection made by utilizing a motor on an optical fiber at a distance of 50 kilometers, utilizing a fiber Bragg grating sensor with an operating wavelength of 1544.9 nm.

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We proposed an artificial neural network-integrated with a fiber Bragg grating (FBG) system for the accuracy of strain measurement. From the result, the artificial neural network has good performance comparing to the Gaussian fitting method.

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An optical setup that is equivalent to an electrically rotating polarization element (ERPE) is proposed. The principal axis of the ERPE can be changed by applying an electric signal on an electro-optic modulator of this setup. This ERPE can be applied for a linear phase retarder with arbitrary phase retardation.

 

In this study, Zemax is used to simulate the human eye and analyze the difference between the front and the rear of the frog mirror with a third-order aspheric lens. The effective focal length is used to optimize the parameters of the first and second sides of the frog mirror to achieve better imaging quality and clearer imaging results. The different refractive between water and air, is discussed in order to reduce the discomfort of the wearer's vision due to the difference in degrees in the water and in the air caused by the power of the frog mirror.

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A sinusoidal intensity modulated light source as a test signal and incident to a spectrometer. In order to separate the tested spectrum from a stray light mixed spectrum, the three-parameter sine fitting algorithm was used to calculate the amplitude intensity corresponding to the specified modulation frequency. The extracted test spectral signal was not affected by stray light.

 

Time-of-flight detection at eye-safe wavelength of 1550nm is demonstrated for LiDAR system in self-driving vehicles. We use a pulse laser diode as the light source, an avalanche photodiode as the signal receiver, and multiple diffused objects with different reflectivity to demonstrate the LiDAR system. Time-of-flight analysis is used to measure the distance between the source and the target. Indoor and outdoor distance up to 65m of single target is demonstrated.

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In this study, the liquid lens was integrated into the AOI imaging system. Because the liquid lens can quickly adjust the focal length, we apply it to the image focal length scan, and combine the sharpness algorithm to calculate the image sharpness curve. Experimental results, this system architecture and sharpness algorithm, can find the best focus position in the imaging system.

 

In this study, we use a birefringent polymer PEN immersed in ethanol solution to monitor the volatilization phenomenon based on a polarimetric spectral interference measurement scheme. Since the refractive index of ethanol solution change as well as volatilization in contact with air, the dip wavelength shift gradually due to the condition change of interference phase. The measurements indicate a sensitivity to RI changes of 7.7×104 nm/RIU, resulting in a detection limit of about 1.3×10-5 RIU.

 

A BBO optical angle sensor was demonstrated successfully for the non-contact fluidic concentration measurements in a common path heterodyne interferometer. The achievable concentration and RI measurement resolutions are 45 ppm and 7.2×10-6 RIU, respectively.

 

This paper proposes a Differential Interference Contrast Microscope (DICM), which uses a liquid crystal cell as a shearing element between the objective lens and the sample, and uses a quarter wave plate with a polarization camera to introduce the phase. Compared with the traditional DICM,The system has the advantage of not requiring mechanical action to switch the shearing direction and can complete the phase shift instantly. It is superior to previous architectures in terms of time cost, operational complexity and applicability.

 

We use a simple polymer dispersed liquid crystal (PDLC), consisted of 30% LC and 70% commercially available UV-curable epoxy, connected with free-standing rotary triboelectric nanogenerator (r-TENG) to evaluate the behavior of LC inside polymer matrix by synchronously recording the triboelectric voltages and currents. The experimental results revels that the applied current, not voltage, determines the performance of PDLC devices. Under the same supplied currents from r-TENG, the performance of one piece PDLC is the same as 9 pieces of series connected PDLCs.

 

This paper mainly describes the use of MTF and WFE as the evaluation function of the optical telescope during the manufacturing and assembly process to control the performance of the optical system step by step. By tolerances allocations in each stage, the tolerance margin and the success criteria is clearly understood, the critical path in the overall process could be easily shown. It is much better and confident for the project management. If every process stage could follow the budget allocation, the final performance of the overall optical system should be expected to meet the requirements.

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The color vision inspection system under the full-color gamut spectrum can be used for human color discrimination. This advanced design has the characteristics of quick test-time control, humanized operation design, and sensitive, accurate and robust measuring results for the degree of color blindness by using about 100 lux at white-light illuminance.

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In this case study, the nonrotationally symmetric systematic error of testing a concave hyperbolic mirror is presented. Based on the Interferometric test with rotational shears technique, the nonrotationally symmetric systematic error are analyzed and compared with both of the multi-angle averaging method and Zernike terms analysis method.

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In this paper, a large-area multipoint sensor using machine learning (ML) for a highly reliable fiber Bragg grating (FBG) sensor system is proposed. The experimental results prove that ML can provide the best sensing path from multiple different sensing paths in the network.

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This paper uses 5 million original test data for comparison and analysis, uses the
random forest method in machine learning (ML) to adjust the test machine parameters and
achieves the best UPH (Units per hour), and passes the streamlined man-machine guidance
surface synchronization verification , And then use the adjustment of the optical fiber detector
to optimize the optimal setting value of the production machine parameters and the level of
UPH

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This article introduces a profiler equipped with a hexapod, a moving stage, a rotating spindle, and an autocollimating probe. This setup measures directions of points in polished surface instead of relative sag on these surface.

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A phase-shifted fringe projection profilometer is developed to monitor the surface profile of the fabricated layers in a metal power bed fusion manufacturing system. Using structured light illumination with digital projector, a series of the distorted fringes projected on the samples are recorded by cameras. Distorted fringe images are decoded to obtain the phase information, unwrapped by the proposed phase-offset approach and reconstruct the surface profile proportional to the unwrapped phases. The optical system are designed and analyzed theoretically, which show the possibility to achieve surface contour imaging sub-millimeter axial precision and to realize real-time surface profile monitoring.

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We combine the design of spot-defect and azimuthal symmetry breaking into a resonator to generate optical vortices. This spiral-phase defect structure is implemented by reflective spatial light modulator and lead to direct lasing of topological charge tunable vortex lasers confirming the theoretical predictions by modal decompositions.

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Techwiz LCD 3D is currently a mature liquid crystal display design and simulation software, which can be used for liquid crystal, TFT simulation, panel, optical. In the process of research, we often need to expand the range of simulation to check the characteristics of the liquid crystal at a location. In order to maintain the accuracy of the simulation, we often set the mesh small. However, large-scale simulation is accompanied by numerous data. Under a long simulation time, the computer cannot withstand lots of data. For improving this situation, we have proposed a method of Segmented simulation.

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Light is not only for human vision but may also be a non-pharmacological method to improve the sleep cycle and quality life of people who have to live with dementia. Using LEDs, we have designed a 24-hour lighting timetable to simulate changes in daytime spectra for installation in long-term care and family homes.

 

Here we demonstrate an end pumped Nd:YVO4 crystal by a light emitting diode with 1.2W and wavelength of 810nm.Through commercial software ZEMAX simulation designs the coupling lens sets, which are used to couple light into the laser crystal. The power of 1064nm infrared increased with LED light intensity was observed. The maximum coupling intensity of LED was 79.09W/cm2.

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Organic light emitting diode (OLED) adopting high-index substrates (refractive index > 1.8-1.9) and highly horizontal-dipole ratio emitters (horizontal dipole ratio > 85%) has shown great enhancement for light extraction. Together with low index carrier transport layer and optimized transparent electrode thickness, all waveguide modes and surface plasmon modes can be suppressed and high optical coupling efficiency into substrates of ~90% can be obtained. In our experiment, combining sapphire substrate (n~1.78), recently developed high horizontal emitting dipole (87%) emitters, and external extraction lens, OLED devices having external quantum efficiency (EQE) over 80% was successfully realized.


 

A novel method for the rapid detection of immunoglobulin G (IgG) antibody by using the Mueller matrix polarimetry technique is proposed. The feasibility of the proposed sensor is demonstrated by measuring the IgG concentration human serum solutions over the range of 0-250 ng/ml. The results show that the circular dichroism properties increase linearly with an increasing IgG concentration over the considered range. Moreover, the proposed device has a resolution of 5-10 ng/ml and a response time of less than three minutes.