High-resolution portable lens-free on-chip microscopy with RGB LED via pinhole array

Lens-free on-chip microscopy with RGB LEDs(LFOCM-RGB)provides a portable,cost-effective,and high-throughput imaging tool for resource-limited environments.However,the weak coherence of LEDs limits the high-resolution imaging,and the luminous surfaces of the LED chips on the RGB LED do not overlap,making the coherence-enhanced executions tend to undermine the portable and cost-effective implementation.Here,we propose a specially designed pinhole array to enhance coherence in a portable and cost-effective implementation.It modulates the three-color beams from the RGB LED separately so that the three-color beams effectively overlap on the sample plane while reducing the effective light-emitting area for better spatial coherence.The separate modulation of the spatial coherence allows the temporal coherence to be modulated separately by single spectral filters rather than by expensive triple spectral filters.Based on the pinhole array,the LFOCM-RGB simply and effectively realizes the high-resolution imaging in a portable and cost-effective implementation,offering much flexibility for various applications in resource-limited environments.

Lens-free wavefront shaping method for a diffuse non-lineof-sight link in visible light communication

In this Letter,we propose and experimentally demonstrate a lens-free wavefront shaping method that utilizes synchronized signal block beam alignment and a genetic algorithm(SSBGA)for a diffuse non-line-of-sight(NLOS)visible light communication(VLC)system.The proposed method effectively controls the position and mobility of visible light beams by partitioning spatial light modulator pixels and manipulating beams to converge at distinct spatial positions,thereby enhancing wavefront shaping efficiency,which achieves a significant 23.9 dB optical power enhancement at+2 mm offset,surpassing the lens-based continuous sequence(CS)scheme by 21.7 dB.At+40°angle,the improvement reaches up to 11.8 dB and 16.8 dB compared to the results with and without lens-based CS,respectively.A maximum rate of 5.16 Gbps is successfully achieved using bit-power loading discrete multi-tone(DMT)modulation and the proposed SSBGA in an NLOS VLC system,which outperforms the lens-based CS by 1.07 Gbps and obtains a power saving of 55.6%during the transmission at4 Gbps.To the best of our knowledge,this is the first time that high-speed communication has been realized in an NLOS VLC system without a lens.

Deep learning virtual colorful lens-free on-chip microscopy

Currently, it is generally known that lens-free holographic microscopy, which has no imaging lens, can realize a large field-of-view imaging with a low-cost setup. However, in order to obtain colorful images, traditional lensfree holographic microscopy should utilize at least three quasi-chromatic light sources of discrete wavelengths,such as red LED, green LED, and blue LED. Here, we present a virtual colorization by deep learning methods to transfer a gray lens-free microscopy image into a colorful image. Through pairs of images, i.e., grayscale lens-free microscopy images under green LED at 550 nm illumination and colorful bright-field microscopy images, a generative adversarial network(GAN) is trained, and its effectiveness of virtual colorization is proved by applying it to hematoxylin and eosin stained pathological tissue samples imaging. Our computational virtual colorization method might strengthen the monochromatic illumination lens-free microscopy in medical pathology applications and label staining biomedical research.

老年性白内障晶体游离氨基酸的测定

检出人晶体中的天门冬氨酸、苏氨酸、丝氨酸、谷氨酸、甘氨酸、丙氨酸、胱氨酸、缬氨酸、蛋氨酸、异亮氨酸、亮氨酸、酪氨酸、苯丙氨酸、赖氨酸、组氨酸、色氨酸、精氨酸和脯氨酸共18种游离的氨基酸。但是在老年性白内障晶体中,天门冬氨酸、苏氨酸、丝氨酸、谷氨酸、丙氨酸、胱氨酸、缬氨酸、蛋氨酸、异亮氨酸、亮氨酸和组氨酸11种氨基酸的含量明显降低(P<0.05),其中5种是必需氨基酸,这可为进一步研究白内障形成的机制及其临床治疗提供一些线索。

自由曲面光学元件气囊抛光进动运动控制技术

针对自由曲面光学元件的加工特点,研究气囊抛光自由曲面光学元件进动运动控制技术,用于求出气囊工具进动过程中两虚拟轴的转角,实现对气囊自转轴空间位置的控制。以气囊自转轴为研究对象,由于自由曲面光学元件上每个点的法线三维坐标都不相同且气囊进动抛光过程中气囊自转轴与工件加工点局部法线夹角不变,提出建立基坐标系和抛光点对应三维空间坐标系的方法,得到抛光过程中气囊自转轴的空间位置变化情况,而后利用旋转坐标变换得到气囊抛光进动运动控制模型;在所建立的自由曲面光学元件气囊抛光进动运动控制模型中加入控制算法,求出抛光自由曲面光学元件各点时气囊工具两个虚拟旋转轴的转角。利用Matlab对自由曲面光学元件不同方向截面进行仿真抛光试验,得到自由曲面各方向上气囊抛光进动运动曲线以及仿真进动角曲线,结果证明了自由曲面光学元件气囊抛光进动运动控制模型及控制算法的正确性。

内渐进镜片加工中的过切判据的研究

针对内渐进镜片在加工过程中出现过切的情况,提出一种判断方法。该方法使用双三次样条曲面参数方程计算自由曲面各点曲率半径最小值,通过三维软件对曲面曲率半径进行计算,研究镜片在机床上实现加工的判据。由分析和计算表明,若曲面加工范围内存在某些点的曲率半径小于给定的机床刀具半径,则机床无法加工内渐进镜片的曲面。

渐进多焦点镜片的设计与慢刀伺服车削

为解决自由曲面眼镜片设计加工的难题,进行了渐进多焦点镜片的设计和加工。提出了渐进多焦点曲面的参数化设计方法,通过控制曲面曲率来控制曲面的面型,避免了复杂的数学计算。在对曲面光焦度和像散分布进行计算的基础上对曲面进行评价。提出了离散曲面的刀触点生成方法,将慢刀伺服车削技术用于该渐进多焦点曲面的加工。实验结果证明了设计方法的正确性和加工方法的可行性。

基于NURBS的光学镜片重构算法研究

NURBS表示适用于主流及普遍的曲面设计。针对光学渐进镜片在设计中要保证光顺性且局部修改能够保持球镜度不变的问题,文中提出了一种利用NURBS重构技术的优化算法。因为NURBS曲面具有良好的局部修改性以及仿射与透视变化下的不变性,所以选择用NURBS重构出光学镜片且界定曲面部分修改的研究方法。通过预处理得到镜片上的型值点,设计了基于反求控制点的3次NURBS曲面重构算法,定义了基本概念,解决了型值点的选取,二次方法求解控制点,再次曲面拟合和界定局部修改等问题,并通过实验验证了文中算法的有效性。

Handheld high-throughput plasmonic biosensor using computational on-chip imaging

We demonstrate a handheld on-chip biosensing technology that employs plasmonic microarrays coupled with a lens-free computational imaging system towards multiplexed and high-throughput screening of biomolecular interactions for point-of-care applications and resource-limited settings.This lightweight and field-portable biosensing device,weighing 60 g and 7.5 cm tall,utilizes a compact optoelectronic sensor array to record the diffraction patterns of plasmonic nanostructures under uniform illumination by a single-light emitting diode tuned to the plasmonic mode of the nanoapertures.Employing a sensitive plasmonic array design that is combined with lens-free computational imaging,we demonstrate label-free and quantitative detection of biomolecules with a protein layer thickness down to 3 nm.Integrating large-scale plasmonic microarrays,our on-chip imaging platform enables simultaneous detection of protein mono-and bilayers on the same platform over a wide range of biomolecule concentrations.In this handheld device,we also employ an iterative phase retrieval-based image reconstruction method,which offers the ability to digitally image a highly multiplexed array of sensors on the same plasmonic chip,making this approach especially suitable for high-throughput diagnostic applications in field settings.

Phase-sensitive plasmonic biosensor using a portable and large field-of-view interferometric microarray imager

Nanophotonics,and more specifically plasmonics,provides a rich toolbox for biomolecular sensing,since the engineered metasurfaces can enhance light–matter interactions to unprecedented levels.So far,biosensing associated with high-quality factor plasmonic resonances has almost exclusively relied on detection of spectral shifts and their associated intensity changes.However,the phase response of the plasmonic resonances have rarely been exploited,mainly because this requires a more sophisticated optical arrangement.Here we present a new phase-sensitive platform for high-throughput and label-free biosensing enhanced by plasmonics.It employs specifically designed Au nanohole arrays and a large field-of-view interferometric lens-free imaging reader operating in a collinear optical path configuration.This unique combination allows the detection of atomically thin(angstrom-level)topographical features over large areas,enabling simultaneous reading of thousands of microarray elements.As the plasmonic chips are fabricated using scalable techniques and the imaging reader is built with low-cost off-the-shelf consumer electronic and optical components,the proposed platform is ideal for point-of-care ultrasensitive biomarker detection from small sample volumes.Our research opens new horizons for on-site disease diagnostics and remote health monitoring.

基于图像变换的自由曲面光学透镜面形测量

对称中心的自由曲面光学透镜的光学表面面形测量 ,是光学加工制造领域的难题。为达到高精度测量 ,提出一种可用于自由曲面光学透镜在线光学测量方法。基于光学透镜的图像变换特性与其光学表面面形之间存在着的拓扑关系 ,通过对标准输入图像和经过待测自由曲面光学透镜变换后的输出图像进行智能辨识、分析和处理 ,求出该光学透镜的变换矩阵 ,并据此精确测量出待测光学透镜的曲面面形。实验结果表明 :基于图像变换的测量方法的测量误差小于 2～ 3μm,能够适用于自由曲面光学透镜的非接触。