Since its advent in the 1970s, optical tweezers have been widely deployed as a preferred non-contact technique for manipulating microscale objects. On-chip integrated optical tweezers, which afford significant size, weight, and cost benefits, have been implemented, relying upon near-field evanescent waves. As a result, these tweezers are only capable of manipulation in near-surface regions and often demand high power since the evanescent interactions are relatively weak. We introduce on-chip optical tweezers based on freeform micro-optics, which comprise optical reflectors or refractive lenses integrated on waveguide end facets via two-photon polymerization. The freeform optical design offers unprecedented degrees of freedom to design optical fields with strong three-dimensional intensity gradients, useful for trapping and manipulating suspended particles in an integrated chip-scale platform. We demonstrate the design, fabrication, and measurement of both reflective and refractive micro-optical tweezers. The reflective tweezers feature a remarkably low trapping threshold power, and the refractive tweezers are particularly useful for multiparticle trapping and interparticle interaction analysis. Our integrated micro-optical tweezers uniquely combine a compact footprint, broadband operation, high trapping efficiency, and scalable integration with planar photonic circuits. This class of tweezers is promising for on-chip sensing, cell assembly, particle dynamics analysis, and ion trapping.

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基于自由形式光学器件的片上光学镊子

自从1970年代问世以来，光学镊子已被广泛地用作处理微尺度物体的首选非接触技术。依靠近场e逝波，已经实现了具有显着尺寸，重量和成本优势的片上集成光学镊子。结果，这些镊子仅能够在近地表区域操作，并且由于瞬逝的相互作用相对较弱，因此经常需要高功率。我们介绍基于自由形式微光学的片上光学镊子，该镊子包括通过双光子聚合集成在波导端面上的光学反射镜或折射透镜。自由形式的光学设计为设计具有强三维强度梯度的光场提供了前所未有的自由度，对于在集成的芯片级平台中捕获和处理悬浮颗粒非常有用。我们演示了反射和折射微光学镊子的设计，制造和测量。反射镊子具有极低的捕获阈值功率，而折射镊子对多粒子捕获和粒子间相互作用分析特别有用。我们的集成式微光镊子将紧凑的占位面积，宽带操作，高捕获效率以及可扩展的集成与平面光子电路完美地结合在一起。这类镊子有望用于片上传感，电池组装，粒子动力学分析和离子阱。反射镊子具有极低的捕获阈值功率，而折射镊子对多粒子捕获和粒子间相互作用分析特别有用。我们的集成式微光镊子将紧凑的占位面积，宽带操作，高捕获效率以及可扩展的集成与平面光子电路完美地结合在一起。这类镊子有望用于片上传感，电池组装，粒子动力学分析和离子阱。反射镊子具有极低的捕获阈值功率，而折射镊子对多粒子捕获和粒子间相互作用分析特别有用。我们的集成式微光镊子将紧凑的占位面积，宽带操作，高捕获效率以及可扩展的集成与平面光子电路完美地结合在一起。这类镊子有望用于片上传感，电池组装，粒子动力学分析和离子阱。以及与平面光子电路的可扩展集成。这类镊子有望用于片上传感，电池组装，粒子动力学分析和离子阱。以及与平面光子电路的可扩展集成。这类镊子有望用于片上传感，电池组装，粒子动力学分析和离子阱。