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The direct interfacing of photonic crystal fiber to a metallic nanoantenna has widespread application in nanoscale imaging, optical lithography, nanoscale lasers, quantum communication,in vivosensing, and medical surgery. We report on the fabrication of a needle-shaped plasmonic nanoantenna on the end facet of a photonic crystal fiber using electron-beam-induced evaporation of platinum. We demonstrate the coupling of light from the fiber waveguide mode to the subwavelength nanoantenna plasmonic mode focusing down to the apex of the plasmonic needle using a polarization-resolved far-field side-scatter imaging technique. Our work provides an important step toward widespread application of optical fibers in nearfield spectroscopic techniques such as tip-enhanced Raman and fluorescence microscopy, single-photon excitation and quantum sensors, nanoscale optical lithography, and lab-on-fiber devices.
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Two-photon microscope using a fiber-based approach for supercontinuum generation and light delivery to a small-footprint optical head
In this Letter, we report a low-cost, portable, two-photon excitation fluorescence microscopy imager that uses a fiber-based approach for both femtosecond supercontinuum (SC) generation and light delivery to the optical head. The SC generation is based on a tapered polarization-maintaining photonic crystal fiber that uses pre-chirped femtosecond narrowband pulses to generate a coherent SC spectrum with a bandwidth of approximately 300 nm. Using this approach, high-power, near-transform-limited, wavelength-selectable SC pulses are generated and directly delivered to the imaging optical head. Preliminary testing of this imager on brain slices is presented, demonstrating a high signal-to-noise ratio and sub-cellular imaging capabilities to a depth of approximately 200 µm. These results demonstrate the suitability of the technology forex vivoand potentiallyin vivocellular-level biomedical imaging applications.
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- Award ID(s):
- 1841539
- PAR ID:
- 10133631
- Publisher / Repository:
- Optical Society of America
- Date Published:
- Journal Name:
- Optics Letters
- Volume:
- 45
- Issue:
- 4
- ISSN:
- 0146-9592; OPLEDP
- Format(s):
- Medium: X Size: Article No. 909
- Size(s):
- Article No. 909
- Sponsoring Org:
- National Science Foundation
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