探讨了将"协同创新"理念应用到高校人才培养模式中,改变传统的单一培养模式,并分析针对不同类型学生可实施的方法.面对本科生的培养,开设综合性实验课程,融合不同专业学生共同完成实验内容,培养学生的协作能力,在此基础上鼓励学生参加各类创新项目、创新大赛.面对研究生的培养,建设导师团队,通过导师的协作交流带动所属研究生的深层合作,并通过共同完成研究课题或者申请项目加深协同效应.

Organic light-emitting field-effect transistors (OLEFETs) are regarded as an ideal device platform to achieve electrically pumped organic semiconductor lasers (OSLs). However, the incorporation of a high-quality resonator into OLEFETs is still challenging since the process usually induces irreparable deterioration to the electric-related emission performance of the device. We here propose a dual distributed Bragg reflector (DBR)-based planar microcavity, which is verified to be highly compatible with the OLEFETs. The dual DBR planar microcavity shows the great advantage of simultaneously promoting the quality (Q) factor and outcoupling efficiency of the device due to the reduced optical loss. As a result, a moderately high Q factor of ∼160, corresponding to EL spectrum linewidth as narrow as 3.2 nm, concomitantly with high outcoupling efficiency (∼7.1%) has been successfully obtained. Our results manifest that the dual DBR-based planar microcavity is a promising type of resonator, which might find potential applications in improving the spectra and efficiency performance of OLEFETs as well as in OLEFET-based electrically pumped OSLs.

Chemical vapor deposition (CVD) diamond crystal is considered as an ideal material platform for Raman lasers with both high power and good beam quality due to its excellent Raman and thermal characteristics. With the continuous development of CVD diamond crystal growth technology, diamond Raman lasers (DRLs) have shown significant advantages in achieving wavelength expansion with both high beam quality and high-power operation. However, with the output power of DRLs reaching the kilowatt level, the adverse effect of the thermal impact on the beam quality is progressively worsening. Aiming to enunciate the underlying restrictions of the thermal effects for high-power DRLs (e.g., recently reported 1.2 kW), we here establish a thermal-structural coupling model, based on which the influence of the pump power, cavity structure, and crystal size have been systematically studied. The results show that a symmetrical concentric cavity has less thermal impact on the device than an asymmetrical concentric cavity. Under the ideal heat dissipation condition, the highest temperature rise in the diamond crystal is 23.4 K for an output power of ~2.8 kW. The transient simulation further shows that the heating and cooling process of DRLs is almost unaffected by the pump power, and the times to reach a steady state are only 1.5 ms and 2.5 ms, respectively. In addition, it is also found that increasing the curvature radius of the cavity mirror, the length and width of the crystal, or decreasing the thickness of the crystal is beneficial to alleviating the thermal impact of the device. The findings of this work provide some helpful insights into the design of the cavity structure and heat dissipation system of DRLs, which might facilitate their future development towards a higher power.

: An incoherent digital holographic imaging system based on the Michelson interferometer with structured light illumination is proposed, which uses a spatial light modulator (SLM) to realize horizontal and vertical cosine grating illumination patterns to improve the lateral resolution of the imaging system. Using MATLAB software to carry out simulation imaging and numerical reconstruction, the high-resolution reconstructed image under the system is obtained. It theoretically proves that this method can effectively improve the resolution of the incoherent digital holography system. And build the corresponding incoherent light self-interference digital holographic imaging system. By imaging the USAF1951 resolution target, further verified the applicability of the super-resolution imaging method based on structured light illumination experimentally. Overview: As a super-resolution optical imaging technology, structured light illumination technology carries an object’s high-frequency information into the optical system in the form of moiré fringes through structured illumination, breaking the diffraction limit in traditional optical imaging and improving image resolution. An incoherent self-interference digital holography based on the Michelson interferometer can accurately record an object's phase and intensity information. It has the characteristics of fast real-time, non-contact, non-marking, three-dimensional imaging, etc., and has essential research significance in biomedical imaging and materials science. In this paper, an incoherent digital holographic imaging system based on the Michelson interferometer with structured light illumination is proposed, which uses a spatial light modulator (SLM) to realize horizontal and vertical cosine grating illumination patterns to improve the lateral resolution of the imaging system. Perform simulation and verification experiments in uniform and structured light illumination mode to explore the high-resolution imaging results of the resolution target. We obtained in simulation imagings: First, the resolved minimum element of the resolution target is Group 4 element 3 (20.16 lp/mm) in Figure 3(e) under uniform light illumination. Then, the algorithm is used to modulate the resolution target to realize the structured light illumination mode. The resolved minimum resolution element of the resolution target is Group 5 element 2 (35.92 lp/mm) in Figure 4(c). We get in the verification experiments: First, use the algorithm to generate a mask with a value of 1 on the SLM to adjust the illumination mode to the uniform light illumination mode, and the resolved minimum resolution element of the resolution target is the Group elements 4 (45.25 lp/mm) in Figure 5(e). Using another algorithm to load cosine gratings of 20 lp/mm and 40 lp/mm on the SLM to adjust the illumination mode to structured light illumination mode, the resolved minimum element of the resolution target is Group 6 element 1 (64 lp/mm) and Group 6 element 4 (90.51 lp/mm) in Figure 6(a1)

Tunable edge enhancement can selectively emphasize the edge features of objects. We demonstrate a higher-order spiral Fresnel incoherent correlation holography system to realize isotropic edge enhancement with tunable width. The spatial light modulator is space-division multiplexed by a conventional lens and a spiral lens with a series of higher-order Laguerre–Gaussian phases. The effects of the radial quantum number p and the angular quantum number l on the spatial filtering are theoretically discussed, as well as confirmed by simulations and experiments. Reconstruction images of resolution target, hairs and label-free onion cells all show obvious tunable edge enhancement effects, which makes the edge information easier to be identified. Furthermore, double-edge enhancement is also detected for the first time.

半导体有源器件和无源元件是构成各种集成电路的基本要素,其中半导体有源器件是决定集成电路性能的核心元件,"半导体器件物理"课程是电子科学与技术学科重要的专业基础课程.本文针对学生专业基础薄弱、技术发展日新月异、纯理论课堂教学效果不佳等问题,提出构建系统知识框架、探索虚拟仿真实践教学模式、建设课程网络学习平台等改革措施.通过以上措施夯实学生微电子专业基础,提高学生动手实践能力和创新意识.

Fresnel incoherent correlation holography (FINCH) shows great advantages of coherent-light-source-free, high lateral resolution, no scanning, and easy integration, and has exhibited great potential in recording three-dimensional information of objects. Despite the rapid advances in the resolution of the FINCH system, little attention has been paid to the influence of the effective aperture of the system. Here, the effective aperture of the point spread function (PSF) has been investigated both theoretically and experimentally. It is found that the effective aperture is mainly restricted by the aperture of the charge-coupled device (CCD), the pixel size of the CCD, and the actual aperture of the PSF at different recording distances. It is also found that the optimal spatial resolution exists only for a small range of recording distance, while this range would become smaller as the imaging wavelength gets longer, leading to the result that the optimal spatial resolution is solely determined by the actual aperture of the PSF. By further combining the FINCH system with a microscopy system and optimizing the recording distance, a spatial resolution as high as 0.78 μm at the wavelength of 633 nm has been obtained, enabling a much higher quality imaging of unstained living biological cells compared to the commercial optical microscope. The results of this work may provide some helpful insights into the design of high-resolution FINCH systems and pave the way for their application in biomedical imaging.

Fresnel incoherent correlation holography technology can not only combine other techniques for three-dimensional imaging of objects but also has the inherent ability to create a super-resolution reconstruction. It generally realizes reconstructions of objects through phase-shifting algorithm, so it is not appropriate for the real-time imaging of living cells. We propose a single-shot microscopic imaging method, which adjusts the pixel distribution of the SLM based on a two-step phase-shifted mask to make sure beams can travel along their respective optical axis, then the multiplexed phase-shifted hologram can be obtained simultaneously. Experimental reconstructions of some objects are used to verify the effectiveness of our proposal. It is hopeful to realize the real-time imaging of living cells by using this method.

Fresnel incoherent correlation holography (FINCH) showed its potential for three-dimensional images with super-resolution by using incoherent light sources. However, regular FINCH re-quires at least two times of holographic recording, and is not suitable for the instantaneous measurement of dynamic objects. Here, we propose the single-shot FINCH technology to realize real-time imaging. With three dual-lens patterns mixed regularly into a phase mask, the new system can capture a compound hologram, which contains three phase-shifted sub-holograms on different areas of image plane. We draw a comparison of both methods, and find it suitable for single-shot FINCH to realize holographic recording in real-time. A dice is used as a test object to record its dynamic rotational movement and holograms from different angles. We also clearly record the whole process of a drop of glue falling vertically under the force of gravity. Experi-mental results show the capability of single-shot FINCH system to record moving objects dynamically. This system provides a simple and flexible way to achieve real-time recording based on FINCH.

We proposed an incoherent self-interference digital holography imaging system based on the Michelson interferometer. The proposed system records holograms of USAF1951 resolution target, herbaceous stem crosscut, and osteocyte. The reconstruction of the captured hologram using a three-step generalized phase shift can effectively eliminate bias and a twin image and obtain a clear reconstructed image. Element 3 in group 9 on the USAF1951 resolution target can be clearly seen, and the resolution achieves 645 1p/mm. Results indicate that the diffraction distance can influence the reconstructed image quality, which was confirmed by analyzing their relationship. In addition, the hair hologram was reconstructed, thereby demonstrating that the proposed system can record a 3D image of the object. (C) 2021 Society of Photo-Optical Instrumentation Engineers (SPIE)

Fresnel incoherent correlation holography (FINCH) is a unique three-dimensional (3D) imaging technique which has the advantages of scanning-free, high resolution, and easy matching with existing mature optical systems. In this article, an incoherent digital holographic spectral imaging method with high accuracy of spectral reconstruction based on liquid crystal tunable filter (LCTF) and FINCH is proposed. Using the programmable characteristics of spatial light modulator (SLM), a series of phase masks, none of whose focal lengths changes with wavelength, is designed and made. For each wavelength of LCTF output, SLM calls three phase masks with different phase constants at the corresponding wavelength, and CCD records three holograms. The spectral images obtained by this method have a constant magnification, which can achieve pixel-level image registration, restrain image registration errors, and improve spectral reconstruction accuracy. The results show that this method can not only obtain the 3D spatial information and spectral information of the object simultaneously, but also have high accuracy of spectral reconstruction and excellent color reproducibility.

Fresnel incoherent correlation holography is a new technology which can record incoherent object holograms and has important applications in biomedical imaging and 3D remote sensing. The problem of image fusion registration in hyperspectral imaging, three groups of double lens phase masks with constant focal lengths at 492 nm, 562 nm and 672 nm were designed and fabricated. The spatial light modulator called the masks of three wavelengths in turn and recorded the holograms of the objects under the corresponding wavelengths, which owed to the spatial light modulator were programmable. Because of the three-color recorded light was modulated by the corresponding wavelength mask, the spot position size of the CCD surface was the same. The reconstructed images had constant lateral magnification, which could improve the image registration accuracy and avoid complicated spatial registration algorithm of spectral images. The system truly achieved high-precision registration and real-time fusion of holographic color imaging. The color 3D image obtained from the dice holograms had high color reconstruction after numerical reconstruction and color fusion.

Fresnel incoherent correlation holography (FINCH) has the ability to generate three-dimensional images with a super-resolution by using incoherent sources. However, there are unwanted direct current term and twin image in interferograms, so it is of great significance to find a method to eliminate them. Phase-shifting technology is a most widely used technique for this task, but its three-step phase-shifting is not suitable for the instantaneous measurement of dynamic objects, and the quality of reconstructed image with the traditional two-step phase-shifting is lower. In this paper, we present a method of enhancing the resolution through using a two-step phase-shifting technology based on the discrete wavelet transform. After two-step phase-shifting, the resulting hologram is a superposition of multiple forms. The frequency of the resulting hologram is decomposed into different levels through using discrete wavelet transform, then the image is reconstructed after retrieving the low frequency band. Various experiments have verified the effectiveness of this method.

An incoherent self -interference digital holography imaging system based on Michelson interferometer was reported. The system recorded the holograms of USAF1951 resolution target, onion epidermal cell and herbaceous stem crosscut. Reconstructing the captured hologram by three -step generalized phase shift can effectively eliminate zero-order images and twin images, and obtain a high resolution reconstructed image. The element three in group nine on the USAF1951 resolution target can be clearly seen, with a resolution of 645 lp/mm. The effect of diffraction distance on the quality of reconstructed image was studied by analyzing the relationship between them. Moreover, a 3D image of the object can be obtained by this system through reconstruction of the hair hologram.

Incoherent digital holography (IDH) is a recently proposed technique to record three-dimensional (3D) information about the object under incoherent illumination, which breaks the limitation that the holographic recording must be illuminated by coherent light sources and thus makes it usable in white-light and fluorescence illuminating circumstance. In particular, the fresnel incoherent correlation holography (FINCH) is an exemplary method which improves the imaging resolution power and efficiency of incoherent digital holography, and it can obtain 3D distribution of objects swiftly without scanning and moving. However, compared with the conventional optical holography, the FINCH system has a very small field-of-view due to the limitation of the pixel number and size of spatial light modulator (SLM). Therefore, expanding the recording field-of-view of FINCH system is very significant for the application of IDH. In the FINCH, the SLM is used as a diffractive beam splitter so that each spherical beam, originating from each object point, is split into two spherical beams with two different curve radii. Then the interference fringes between the two beams are recorded by CCD. In this paper, the field-of-view angle recorded by the SLM is proposed and analyzed based on the physical and numerical principles of the FINCH system. The field-of-view of imaging system is improved by increasing the effective diameter of SLM through moving the center of the dual-lens optical axis mounted on the SLM to the edge in different directions respectively. An optical setup of reflection mode is constructed to verify the theoretical analysis of this study, and the sub-holograms in different field-of-views are obtained by CCD through changing the masks displayed on the SLM sequentially. Then, the complex holograms in different field-of-views are obtained by using the three-step phase-shifting method, and the reconstructed images are acquired respectively through the angular spectrum method (ASM) by using a computer. Finally, the large field-of-view image is obtained by stitching the reconstructed images in each field-of-view by utilizing the matlab program. The experimental results show that the efficient recording field-of-view of SLM can be increased by 2.77 times with our proposed method. Accordingly, the recording field-of-view of the system is improved significantly. The recording field-of-view of the FINCH system will increase further if the center of the dual-lens optical axis continues to move toward the edge. Therefore, this study provides an important support for the further application of high resolution microscopic imaging with large field-of-view.

Incoherent holography is a hybrid imaging technology with coherent and incoherent processes. Compared with coherent holography, incoherent holography can alleviate coherent noise and speckle noise, and thus achieve higher signal-to-noise ratio. In this article, the incoherent holographic camera based on Michelson interferometer is built, which consists of a telescope, a beam-splitting cube, two plane mirrors, two lenses and a monochromatic charge coupled device. The point spread function (PSF) of the system is determined for the first time according to the Fresnel diffraction theory. Both the simulated and experimental 2D PSFs are coincident with each other. The three-step generalized phase shift interferometry instead of the piezo-actuator is used to eliminate zero-order and twin images. The two one-jiao coins with 15 mm apart and a toy house are recorded under xenon lamp illumination. The reconstructed image clearly demonstrates that the system has the ability to obtain spatial 3D information of an object.

Fresnel incoherent correlation holography (FINCH) is a relatively innovative technology, which can achieve incoherent holograms by using the correlation between the object information and a Fresnel zone plate. In this method, the optical wave front scattered from an object propagates and is incident on a spatial light modulator which a phase mask is mounted on, and then the optical beam is split and phase shifted. The biggest advantage of the FINCH is that it can be matched with any standard optical imaging technology, which can realize microscopic imaging, telescopic imaging, spectroscopic imaging, etc. based on incoherent digital holography, and has important application prospect in remote sensing, astronomy, microscopy, and material analysis. In this paper, based on phase modulation characteristic of spatial light modulator, two types of masks are used. The first mask has an optical axis. And the results show that when the distribution intervals of the three phases on the spatial light modulator (SLM) are larger, the reconstruction image is clearer. On this basis, a new method of mode mounting on the SLM is put forward. The second mask has dual-lens array mode with three phases of 0°, 120°, and 240°, and the three phases respectively correspond to their corresponding optical axis, which means that the mask has three optical axes. Both of the two masks can achieve the single-shot of FINCH. By comparing the two mask forms, we find that the field-of-view of the first mask is larger, which can image the entire resolution board; however, because the sub-phase shift holograms are mixed together and cannot be extracted, the quality of the reconstructed image is worse. The second one can extract three sub-holograms, and the reconstructed image has better quality; but because of smaller imaging field of view, it is suitable for the real-time imaging of micro-organisms and objects. Experiments show that a compound digital hologram including three phase-shifting elements is recorded in charge-coupled device in this way. Three sub-holograms with different phase shift angles are extracted from the compound hologram, and there is no overlapping among the three phase shift holograms. Therefore, the three-phase-shifting technique is usually employed. The sample is reconstructed by numerical reconstruction algorithm. The proposed method may be useful in dynamic process real-time measurement and three-dimensional analysis of the object, and thus providing a new way to promote the development of incoherent digital holography.

Based on the recording and reconstruction theory of Fresnel incoherent digital holography, we analyze and calculate the imaging process of the synthetic aperture incoherent digital holography. The effect of mounting the double lens symmetry mode on a spatial light modulator on imaging characteristics of synthetic aperture incoherent digital holography is simulated, and the simulation results are analyzed. We compare two representation methods including different phase sub-holograms which are first spliced and reconstructed or first reconstructed and spliced. The simulation results are verified by experiments. The results show that the central aperture is the most important sub-aperture. The central aperture and four cross-bonding sub-apertures has better imaging performance, or the double lens symmetry mode can greatly reduce the number of sub-apertures and the holographic recording time. The applicability of synthetic aperture technique in incoherent digital holography is verified.

Digital holographic microscopy (DHM) is one of the most effective methods in imaging the weakly-scattering objects, such as small colloidal particles and most biological cells. Compared to phase contrast and differential interference contrast microscopy, DHM cannot only visualize but quantify these phase objects. In this work, a spiral phase modulated FINCH microscope was implemented. The core of the system is an in-line incoherent interferometer composed of a spatial light modulator (SLM) and a charge-coupled device. In order to enhance image contrast, the SLM was space-division multiplexed by a helical lens and a conventional lens. To study the properties of this vortex imaging system, the precise mathematical model of the Point Spread Function (PSF), which describes the intensity distribution in digital image of the system’s response to a point source, is determined for the first time from the view of wave optics. The experimental 2D PSF agrees well with that of simulated one. When the system is used for biological microscopic imaging the enhancement of edge contrast and the enlargement of field of view are obtained without loss of resolution.