Session Index

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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