Modal interference in optical nanofibers for sub-Angstrom radius sensitivity
| Autor: | Fredrik K. Fatemi, Pablo Solano, Steven L. Rolston, Guy Beadie, J. E. Hoffman, Eliot F. Fenton, Luis A. Orozco |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Birefringence
Optical fiber Materials science Electromagnetically induced transparency business.industry Physics::Optics Polarization (waves) 01 natural sciences Atomic and Molecular Physics and Optics Light scattering Electronic Optical and Magnetic Materials law.invention 010309 optics Vibration Optics law 0103 physical sciences Spatial frequency Whispering-gallery wave 010306 general physics business |
| Zdroj: | Optica. 4:157 |
| ISSN: | 2334-2536 |
| DOI: | 10.1364/optica.4.000157 |
| Popis: | Optical nanofibers (ONFs) of sub-wavelength dimensions confine light in modes with a strong evanescent field that can trap, probe, and manipulate nearby quantum systems. To measure the evanescent field and propagating modes and to optimize ONF performance, a surface probe is desirable during fabrication. We demonstrate a nondestructive near-field measurement of light propagation in ONFs by sampling the local evanescent field with a microfiber. This approach reveals the behavior of all propagating modes, and because the modal beat lengths in cylindrical waveguides depend strongly on the radius, it simultaneously provides exquisite sensitivity to the ONF radius. We show that our measured spatial frequencies provide a map of the average ONF radius (over a 600 μm window) along the 10 mm ONF waist with a 40 pm resolution and a high signal-to-noise ratio. The measurements agree with scanning electron microscopy (SEM) to within SEM instrument resolutions. This fast method is immune to polarization, intrinsic birefringence, mechanical vibrations, and scattered light and provides a set of constraints to protect from systematic errors in the measurements. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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