Compact 90° Releasable Multifiber Optical Connectivity Solution

A compact releasable 90deg optical connectivity solution is proposed, realized, and characterized. It can be used for angled interconnection between two small form factor multifiber connectors, or between one connector and surface mounted multichannel active optical elements such as vertical-cavity surface-emitting lasers and photodetector arrays. This 90deg connectivity system is based on V-groove substrates and an integrated optical microsystem combining two lens arrays and a 45deg mirror. Realized modules feature average fiber-to-fiber optical losses of 1.4 dB (best below 1 dB) for multimode operation over the whole wavelength range from 850 up to 1550 nm. This interconnect solution provides advantages when limited space is available (e.g., in optical distribution frames, splice closures, high-performance computers)     

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.     

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.     

Design, Fabrication, and Integration Technology of Large-Scale Microlens Array for Infrared Charge Coupled Device Application

Infrared charge coupled device (IRCCD) integration with microlens array is an effective method for improving the detecting sensitivity of IRCCD sensors. In this paper, we present the diffractive microlens array (MLA), which is manufactured by the submicron photolithography technology and magnetically enhanced reactive ion etching (MERIE) on infrared quartz substrate. The integration procedure between microlens array and PtSi Schottky-barrier IRCCD chip is introduced in detail. The optical response of IRCCD sensor with microlens array is tested and the average response increases 0.23 in the spectral range of 1.2～5.0 μm. The measuring results show that the large-scale diffractive microlens array is able to improve the detecting sensitivity of IRCCD and that the integration technology mentioned is available.     

半导体激光二极管的光纤耦合技术

将半导体激光二级管（LD）发出的光更高效地注入到光纤中是光纤激光器与光纤放大器研究的先决条件.半导体激光二级管包括二极管单管、条形巴、二维堆栈和二极管阵列等,其各自的耦合技术之间有联系也有区别.分析介绍了有代表性的柱状楔形法、V型槽法、微透镜法等二极管单管与光纤的耦合技术;光纤束耦合法、光束整形法等二极管条形巴与光纤的耦合技术;以及二极管二维堆栈和二极管阵列与光纤的耦合技术等各种光纤耦合技术,比较了这些方法之间的共通点,供今后的研究人员选择和参考.     

Parallel optical transmitter module using angled fibers and a V-grooved silicon optical bench for VCSEL array

We propose an advanced structure of optical subassembly (OSA) for packaging of the vertical-cavity surface-emitting laser (VCSEL) array, using (111) facet mirror of the V-groove ends formed in a silicon optical bench (SiOB) and angled fiber apertures. The feature of our OSA can provide a low optical crosstalk between neighboring channels, a low feedback reflection, and a large misalignment tolerance along the V-groove. We describe the optimized design of fiber angle, VCSEL position, and fiber position. The fabricated OSA structure consists of 12 channels of angled fiber array, 54.7/spl deg/ V-grooves, Au-coated mirrors on (111) end facet of the V-grooves, and flip-chip-bonded VCSEL array on a SiOB. In this structure, the beam emitted from the VCSEL is deflected at the 54.7/spl deg/ mirror of (111) end facet and propagated into the angled fiber. The angled fiber array was polished by 57/spl deg/. Fabricated OSAs showed a coupling efficiency of 30%-50% that is 25 times larger than that obtained from an OSA with a vertically flat fiber array. Our OSA showed large misalignment tolerance of about 90 /spl mu/m along the longitudinal direction in the V-groove. We fabricated a parallel optical transmitter module using the OSA and demonstrated 12 channels /spl times/2.5 Gb/s data transmission with a clear eye diagram.     

Effects of thermally induced optical fiber shifts in V-groove arrays for optical MEMS

Thermally induced optical fiber shifts in the joints consisting of an optical fiber, epoxy adhesive and silicon substrate were simulated using a FEA (finite element analysis) package. Experiments using a real-time micro-moiré system were also performed at temperatures of 25, 40, 60, 85 and 100 °C for confirmation of the FEA results. The optical coupling loss, caused by the fiber shifts, of a single-mode fiber to fiber and a laser diode to a fiber was studied. The results revealed that thermally induced fiber shifts increased with the number of V-groove channels. The optical coupling loss is the greatest during thermal loading for the outer fiber in the four channels V-groove array. Optical losses of 0.334 and 0.346 dB for fiber-to-fiber coupling and 1.54 and 1.56 dB for laser diode to fiber coupling were calculated using the fiber shift values obtained from the FEA and experiments, respectively, for the outermost fiber joint in the four channels V-groove array at 100 °C. The effects of fiber shifts especially the shift of the fiber that is positioned at the outermost V-groove in the array cannot be ignored.     

A surface micromachined optical scanner array using photoresist lenses fabricated by a thermal reflow process

This paper presents the design, fabrication, and operation of a newly developed micromechanical optical scanner array using a translating microlens. We have used photoresist reflow technique to form a microlens on a surface micromachined XY-stage of the scratch-drive actuation mechanism. The lens scanner is placed at the focal length from an incident optical fiber to collimate the transmitting light. The collimated beam is steered two-dimensionally by the XY-motion of the microlens with respect to the incident fiber. We also have developed a theoretical model to predict appropriate initial resist thickness and diameter for the scanning lens. An optical scanning angle of /spl plusmn/7/spl deg/ has been demonstrated by sliding a microlens of 670-/spl mu/m focal length at a physical stroke of /spl plusmn/67 /spl mu/m. Typical angular positioning resolution has been estimated to be 0.018/spl deg/.     

脊形波导耦合的光纤阵列设计

分析了单模光纤与脊形波导的耦合模理论,讨论了其模式特点、最佳耦合条件.在此基础上,计算并设计出满足最佳耦合条件的光纤阵列V-型槽宽度.所设计的光纤阵列在对光纤提供高精度定位的同时,又能保证其与脊形波导的高效率耦合.     

硅基非球面柱面微透镜阵列制备方法

非球面柱面微透镜是一种重要的微光学元件,具有激光准直、聚焦、匀化等功能,在激光通信、光纤传感、激光雷达测距、激光泵浦等系统中具有广泛的应用。为了减小光电系统的体积、提升光纤性能,增大透镜数值孔径是一种常用的解决方案。提出采用折射率更大的硅作为低折射率石英基底的替代材料,使得微透镜在相同体积下数值孔径大幅提升,同时可以降低加工量从而提升制备效率。针对传统石英微透镜的制备方法不再适用硅基微透镜的问题,提出基于掩模移动曝光方法制备光刻胶非球面图案,使用多次涂胶和循环曝光方法,分别解决厚胶涂覆均匀性差及曝光掩模痕迹明显等问题,最终利用等离子体刻蚀技术进行图案转移传递,从而实现微透镜的制备。以数值孔径2.9的硅基非球面柱面透镜阵列为例开展实际制备工艺实验,所制备的微透镜列阵面型精度PV为0.766 μm,表面粗糙度Ra为3.4 nm,表面光洁与设计值符合较好,验证了制备方法的可行性。该方法有望促进非球面柱面微透镜列阵在紧凑化红外光电系统中的大规模应用。     

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...     

用于LED的微透镜阵列的光学性能研究

功率发光二极管(LED)的发展迫切需要提高取光效率,微透镜阵列的二次光学设计是改善其光强分布的有效途径.建立了一种大功率LED的封装结构,二次光学设计采用了微透镜阵列技术,运用光线追踪法研究了这种封装结构的光学性能.分析结果表明,利用微透镜阵列技术能显著改善LED的光学性能,改变其光束分布,将LED的照度衰减降低12%以上,从而得到更加均匀的照明系统.     

Monolithically integrated laser/rear-facet monitor arrays withV-groove for passive optical fiber alignment

An InGaAsP/InP laser monolithically integrated with a rear facet monitor and a fiber V-groove has been demonstrated for the first time. The integrated device incorporates an etched-facet laser fabricated using an in situ, multistep, reactive ion etch process. The integrated V-groove, which is etched directly into the InP substrate, is designed to enable passive alignment of an optical fiber to the active region of the laser. Passive coupling efficiencies of 18% and 8% have been obtained using cleaved multimode and single mode fibers, respectively. Responsivities of the rear facet monitor were as high as 0.49 A/W     

Near hexagonal close-packed optical fiber array for parallel optical interconnection

In conventional optical fiber based two-dimensional (2-D) parallel optical interconnection (POI), optical fiber arrays are aligned to 2-D light sources and detectors using precisely fabricated hole-plate or stacked V-groove plates. All these structures have problems in making positioning components and assembly with high accuracy. For polymer optical fibers with large diameter, the whole dimension of the array will be too large if they are positioned using V-grooves or hole-plate. This paper proposes a 2-D near hexagonal close-packed (NHCP) optical fiber array for 2-D POI. NHCP array has a cross-sectional profile of near-hexagonal lattice and with fibers precisely positioned at each node of lattice. Compared with perfect HCP lattice, NHCP lattice is slightly stretched in one dimension and still have all fibers with nonuniform diameter packed tightly with high packing fraction. The position of fibers in NHCP array is very important when aligned to 2-D light sources and detectors. This paper deduce the analytically expression for the probability distribution of fiber position which is related to variance of fiber diameter and structure parameters of NHCP array, and verified it by computer simulation. Experiment samples of NHCP array have been made showing that NHCP array is easy to be fabricated.     

Flip-chip planar GaInAs/InP p-i-n photodiodes-fabrication andcharacteristics

New flip-chip planar GaInAs/InP p-i-n photodiodes have been fabricated as an array. We describe the structure of the photodiode, the design of a microlens, the fabrication processes, characteristics, and the optical fiber-coupled modules. This photodiode satisfied the requirements for a small junction capacitance and low dark current, good optical fiber coupling, and easy fabrication. We obtained a low dark current with good reproducibility by using two layer polyimide and SiN passivation films. A microlens with a 50 μm φ to 120 μm φ aperture could easily be fabricated with an InP-substrate. By electroplating, flip-chip metal bumps were directly formed on the active region of the photodiode for the first time     

一种掩埋式复眼微透镜阵列

模仿生物复眼,采用光刻离子交换法,在球面玻璃基片中制作了折射率呈三维梯度变化、排列紧密和光学性能良好的微透镜阵列。单元微透镜孔径呈正六角形,光斑大小为4．92μm,相邻透镜元中心距为0．5mm,掩埋透镜高为0．194mm。微透镜阵列具有对称均匀的光学特性,截距自中心至边缘逐渐变小,数值孔径（N．A．）自中心向边缘逐渐变...     

线列混合型石英微透镜/红外探测器阵列的研究

阐述了利用离子束刻蚀技术制作线列长方状拱面石英微透镜阵列的工艺方法，对所制微光学元件的光学性能进行了测试和讨论，所制成的石英微透镜阵列器件在线列ＹＢａ２Ｃｕ３Ｏ７－δ高Ｔｃ超导薄膜红外探测器上得到了应用。实验结果表明，混合型的石英微透镜／红外探测器结构显著改善了线列ＹＢＣＯ高温超导薄膜红外探测器的光响应特性。     

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。     

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.     

一种基于空间光调制器的微透镜阵列制备技术

提出了一种基于空间光调制器的并行光刻制备微透镜阵列的技术。采用数字微反射镜器件输入光刻图形,结合热回流技术,制作任意结构和排布的微透镜阵列。无限远校正显微微缩光学系统的长焦深保证了深纹光刻的实现,热回流法提供了良好的表面光滑度。与传统逐层并行光刻和掩模曝光技术相比,提出的技术方案更加便捷灵活,特别适合制作特征尺寸在数微米至百微米的微透镜阵列器件。得到的微透镜阵列模版经过电铸转移为金属模具,利用紫外卷对卷纳米压印技术在柔性基底上制备微透镜阵列器件,在超薄液晶显示、有机发光二极管(OLED)照明等领域有广泛应用。