Design and Fabrication of Silcon Microlens with Low SAG for 528(H) × 528(V) Infrared Charge-Coupled Device Application

Microlens array is an important optical element to improve the photosensitivity of charge-coupled device (CCD). In this paper, a monolithic integration technology between microlens and 528 × 528 element PtSi Schottky-barrier infrared charge-coupled device (IRCCD) with a pixel size of 30μm × 30μm has been developed. The microlens array with low sag and long focal length is designed based on geometrical optics theory. It is directly formed on the back side of the substrate in IRCCD chip using successive photolithography and A⁺ ion beam etching (IBE) technology. The microlens array is characterized by both surface stylus and point spread function (PSF). The experiment results of integration device between IRCCD and microlens array indicate that the optical signal response is improved obviously and a responsivity increase by a factor of 1.8 in the operation band.     

非梯度折射率型面阵平面微透镜

采用常规的光刻热熔法及灰度掩模技术,结合离子束蚀刻与溅射制作面阵非梯度折射率型平面折射和平面衍射微透镜,定性分析了不同的工艺条件下所得到的平面端面微光学折种和形貌特征。给出了在石英衬底表面通过光刻热熔工艺和氩离子束蚀刻所得到的两种球面及圆弧轮廓特征的面阵册形掩模的表面探针测试曲线,对平面微透镜阵列与IRCCD成像芯片和半导体激光器阵列的集成结构作了初步分析。     

提高CCD图像传感器填充因子的微透镜阵列的研究

为了提高可见光CCD图像传感器的探测灵敏度,提出了516×516元石英微透镜阵列的设计方法,并简要介绍了其制作工艺.测量结果表明,所制作的微透镜阵列有优良的表面轮廓、较好的几何尺寸均匀性和光学性能,大幅度地提高了CCD图像传感器的填充因子.     

多相位256×256衍射微透镜的设计及其光学性能研究

介绍了衍射微透镜阵列的设计原理与制作工艺方法 ,在此基础上运用部分刻蚀法研制出适用于 3～ 5 μm波长多相位 2 5 6× 2 5 6衍射微透镜阵列。利用光通信半导体激光器和探测器建立了一套测试系统 ,并对所设计的多相位衍射微透镜阵列的衍射率和点扩散函数进行了测试 ,8相位和 16相位石英衍射微透镜的衍射率分别高达 80 .2 %和 87.5 % ,完全满足实际应用的要求。     

Hybrid Integration Between Long Focus Microlens Array and IR Detector Array

A special method, named step simulation method, is proposed for fabricating Si microlens array to improve the performance of infrared focal plane array (IR FPA). The focus length of rectangle-based multistep microlens array with element dimension of 40 µm×30 µm is 885.4 µm by the method, which is much longer than the focus length of microlens array fabricated by conventional Fresnel binary optics technique., The large-scale 256×256 element microlens array is hybridintegrated with the PtSi Schottky-barrier IR FPA by optical adhesive. The test results show that diffractive spot size of the microlens is 17 µm×15 µm and the average optical response of the IR FPA is increased by a factor of 2.4.     

衍射微透镜阵列的光学性能研究及测试

对衍射微透镜阵列的光学性能进行理论上的研究,并提出一种测试微透镜阵列衍射效率和点扩散函数的方法,建立了一套测试系统,并对本所研制的128×128衍射微透镜阵列的衍射效率和点扩散函数进行了测试.测试结果证明本所研制的2位相的石英和硅衍射微透镜阵列的性能较好,均匀性较高;而由于工艺和光刻系统的限制,4位相衍射微透镜的制作还存在一些不足,这些都可以从所得到的衍射微透镜的点扩散函数曲线图和衍射效率看出.该方法适于测试具有微小单元尺寸、周期排列的微透镜阵列或单元的衍射效率和点扩散函数.     

Performance Optimization of InSb Infrared Focal-Plane Arrays with Diffractive Microlenses

In this paper, diffractive microlens arrays are studied to concentrate incident light onto the effective photosensitive area of InSb infrared focal-plane arrays and thus enhance the quantum efficiency and reduce the crosstalk. Four designs of diffractive microlenses are investigated by a phase-matched Fresnel-elements approach. The quantum efficiency and crosstalk of the devices are calculated by using a two-dimensional device simulation with unit cell of 50 μm. Light propagation through the diffractive microlenses is simulated by the finite-difference time-domain method based on a rigorous vector solution of Maxwell’s equations. The results show that the highest quantum efficiency of the device with a diffractive microlens array is about 51.6% and the corresponding crosstalk is 5.06%. The quantum efficiency is 2.1% higher than that of the device with a spherical refractive microlens array.     

Monolithic Integration of Diffractive Microlens Arrays and Infrared Focal Plane Arrays

Monolithic integration method has been demonstrated to increase the fill factor of the infrared focal plane arrays (IRFPA). Which is consists of 256×256 Pt-Si schottky barrier charge coupled devices(CCD) operation in 3-5μm IR region. The relative silicon 256×256 element diffractive microlens arrays have been fabricated on the back side of the substrate of the IRFPA using binary optics technology. The aligning process between IRFPA and microlens arrays on each side of the substrate has been completed by IR mask aligner. The testing results show that the imaging quality is very good and the average optical response of the IR FPA is increased by a factor of 3.0, which is improved by about 25% compared with the hybrid integration method in the previous work.     

Diffractive Microlens Array Monolithic Integration with PtSi Focal Plane array

Diffractive microlens arrays can completely collect the light at the focal plane and concentrate it into a smaller spot size on the detector plane, the photodetector area can be substantially reduced. Increased gamma radiation hardening and noise reduction result from the decrease in photodetector sensitive area. The diffractive microlens arrays have been designed by considering the correlative optical and processing parameters for PtSi focal plane array. They have been fabricated on the backside of PtSi focal plane array chip by successive photolithography and Ar⁺ ion-beam-etching technique. The alignment of microlens array with PtSi focal plane array was completed by a backside aligner with IR light source. The practical processes and fabrication method are discussed. The performance parameters of PtSi FPA with diffractive microlens array are presented.     

中红外硅微透镜阵列的离焦效应

本文采用严格数值算法对中红外硅微透镜阵列进行了模拟,该微透镜阵列特征尺寸小于波长工作波长。研究发现该微透镜阵列存在一个显著的离焦效应,其离焦量达到0.4左右,超出了现有的传统理论模型预测范围。对微透镜阵列进行了制作和焦距测试,发现测试结果跟数值模拟基本吻合。微纳衍射光学集成系统中透镜离焦量是系统集成非常重要的一个参数,该研究结果为硅微透镜阵列和中红外探测器光学集成提供有效参考。     

微光学技术及其发展

微光学技术是90年代发展起来的光电学科前沿技术,是光电技术列阵化、微型化、智能化的主要发展方向。微光学技术已经在光通讯、光开关、光扫描、光互连中得到应用。文中就微光学的二元光学、衍／折混事光学、微透镜阵列的原理、工艺方法、主要应用、发展趋势以及我们的研究进行叙述。     

128×128硅衍射微透镜阵列的设计与制备

通过考虑互相关联的光学和工艺参数 ,设计了 3～ 5μm红外 12 8× 12 8硅衍射微透镜阵列。阵列中微透镜的孔径为 10 0μm,透镜 F数为 f / 1.5,微透镜阵列的中心距为 10 0μm。采用多次光刻和离子束刻蚀技术在硅衬底表面制备衍射微透镜阵列。对实际的工艺过程和制备方法进行了讨论 ,对制备出的 12 8× 12 8硅衍射微透镜阵列的光学性能和表面浮雕结构进行了测量。     

固体浸没式红外超表面透镜设计

红外焦平面阵列在各类红外成像系统中发挥着巨大的作用。为提升红外焦平面的工作温度、量子效率和灵敏度,通常使用微透镜阵列作为红外焦平面的聚光器。当前微透镜阵列的制作材料通常与红外探测器材料不同,因此在集成装配时需要额外的工艺手段,工艺难度较大且效率较低。利用微纳光学超表面技术体系,可以在红外探测器衬底材料上直接制作平面式的固体浸没型微透镜阵列,实现前置微透镜与红外焦平面的单片集成。文中以红外探测领域最有潜力的锑化物Ⅱ类超晶格红外探测器为应用目标,设计了一种基于GaSb衬底的固体浸没式红外超表面透镜。设计的超表面透镜在中波红外波段工作,能适用于所有入射偏振。器件设计焦距为100 μm,理论上在目标波长下的最高聚焦效率达到70.7%,数值孔径(NA)达到1.15。该设计可以推动微透镜阵列向扁平、超薄、轻量的方向发展,简化微透镜阵列与红外焦平面阵列的集成工艺,有望提升红外焦平面的探测效率,并降低制造成本。     

一种新型聚合物微透镜阵列的制造技术

提出了一种利用软模压印制备微透镜阵列的技术.采用传统的光刻胶热熔方法制备微透镜阵列母板,利用复制模具的方法在聚二甲基硅氧烷(PDMS)上得到一个和母板表面图形相反的模具,最后通过压印的方法把PDMS模具上的图形转移到涂有紫外固化胶的玻璃基片上,待紫外胶完全固化后可得到和母板一致的微透镜阵列.经过测试微透镜阵列的焦点图像和表面形貌可发现最后制备的微透镜阵列表面形貌均匀、聚焦性能良好、光忖强均匀.     

设计参数变化对衍射微透镜的影响

给出了多台阶衍射微透镜的设计公式,并阐述了旋转体时域有限差分法。通过采用该方法对设计的多台阶衍射微透镜进行分析,说明了设计参数(包括焦距、入射波长、透镜材料折射率)的变化与微透镜衍射效率、爱里斑半径、最大场强变化的关系,对部分结果的定性讨论与数值分析结果一致。     

采用单步光刻和湿法腐蚀工艺制作高性能衍射微透镜

采用单步光刻和湿法腐蚀工艺,低成本快速制作面向高性能蓝光和红光DVD光学头物镜的衍射微透镜.所制微光学结构的表面粗糙度在纳米量级,衍射相位台阶的高度在亚微米量级并可以根据需求灵活调整,通光孔径在毫米至厘米量级的范围内可调.组成衍射微透镜的大量基本相位结构,可以根据入射和出射光束的形貌特征及参数指标,通过衍射积分算法灵活设置和排布.远场光学测试显示了所制衍射微透镜的高衍射效能.     

Integration of 256×256 Element Si Microlens Arrays with PtSi IR Detector Array Devices

Diffractive 11-phase-level Si microlens arrays are fabricated by a special method, i.e. part-etching. The method can increase focal length of diffractive microlens arrays. By using this method, the microlens arrays on the back side of the Si substrate and PtSi IR focal plane arrays(FPAs) on the front side of the same wafer are monolithically integrated together. The IR response characteristics of the integrated devices are improved greatly.     

基于激光加工的玻璃透镜阵列制备

为了实现蓝宝石微透镜阵列模板的可控制备,采用刻蚀辅助激光加工技术得到了形貌可控、排列均匀的密排步蓝宝石微凹透镜阵列模板,并结合高温浇铸转写技术实现了K9玻璃微凸透镜阵列的快速制备;基于蓝宝石和玻璃之间较大的热膨胀系数差,实现了蓝宝石和玻璃的有效分离.结果表明,所制备的玻璃透镜阵列具有较高的表面平滑度,表面粗糙度仅有2n...     

主光轴平行于基底的微透镜阵列设计与制作

用聚二甲基硅氧烷(PDMS)软光刻工艺实现了一种主光轴平行于基底的微透镜阵列。首先对微透镜形成过程中的PDMS薄膜受力和变形情况进行了分析,并采用有限元分析方法对不同压力、不同厚度的薄膜变形情况进行了模拟,确定了合理的微透镜腔体结构;然后利用SU-8负模制作了PDMS微透镜腔体,将腔体与盖片进行了密闭封装,通过一定的压力向其注入紫外固化光学胶成型了微透镜阵列;最后使用自制装置对微透镜阵列的聚焦效果进行了测试。结果表明,提出的制作方法简单易行、成本低廉和焦距可控,而且易与其它的微系统集成到同一芯片。     

Surface-mountable silicon microlens for low-cost laser modules

A surface-mountable silicon microlens that can be passively aligned in a silicon V-groove is proposed. The microlens has a diffractive optical element on the end facet of a semicylindrical structure whose diameter is identical to that of a single-mode fiber (SMF). The experimental result of coupling efficiency between a distributed feedback laser diode and SMF shows low loss (-3.0 dB) as determined using the microlens. Monte Carlo simulations indicate that the microlens is suitable for low-cost and high-performance optical modules for metro networks.