We investigate binding and plasmonic coupling between optically trapped 80 nm silver spheres using a combination of spectroscopic sensing and 3D interferometric laser particle tracking on a 1 μs time scale. We demonstrate that nanoparticle coupling can be either spontaneous or induced by another particle through confinement of diffusion. We reveal ultrafast entries and exits of nanoparticles inside the optical trap, fast particle rearrangements before binding, and dimer formation allowing new insights into nanoparticle self-assembly.

We describe a novel approach for fabricating customized convex as well as concave micro-lenses using substrates with sophisticated pinning architecture and utilizing a drop-on-demand jet printer. The polymeric lens material deposited on the wafer is cured by UV light irradiation yielding lenses with high quality surfaces. Surface shape and roughness of the cured polymer lenses are characterized by white light interferometry. Their optical quality is demonstrated by imaging an USAF1951 test chart. The evaluated modulation transfer function is compared to Zemax simulations as a benchmark for the fabricated lenses.

We present a novel bimodal endoscopic imaging probe that can simultaneously provide full-field white-light video microscopy and confocal optical coherence tomography (OCT) depth scans. The two modalities rely on spectrally separated optical paths that run partially in parallel through a micro-optical bench system, which has a cross-section of only 2  mm×2.76  mm and is realized via standard silicon micromachining techniques. With a numerical aperture of 0.061, the video modality has a resolution and field of view of 9.3 and 1240  μm×1080  μm, respectively. The resolution is limited by the pixel spacing of the coherent fiber bundle, which relays the acquired image from the distal to the proximal end. A custom-designed diffractive optical element placed within the video imaging path significantly improves the image contrast by up to 45% in the medium frequency range. The OCT modality is optimized for 830 nm center wavelength, and works in a confocal arrangement with an NA of 0.018. It provides single-point depth probing at the center of the video image with a lateral resolution of 20 μm. Through its compact footprint and enhanced functionality, the probe can provide depth-resolved guiding capability for existing laparoscopes and represents a major step toward a new class of multimodal endoscopic imaging probes.

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We present the first silicon-based endomicroscope that combines wide field and confocal imaging modalities in a single device, whose functionality includes simultaneous op eration of bright-field microscopy and optical coherence to mography (OCT). This highly-compact multi-modal probe is based on silicon bulk micromachining and has cross-sectional dimensions of 2 x 2.76nun 2 . The achieved lateral resolutions are 6.2 /JIll and 17.8/Jm for bright-field microscopy and OCT, respectively. KEYWORDSMulti-modal imaging, optical coherence tomography, bright-field microscopy, silicon optical bench.