Focusing characteristics of optical fiber axicon microlens for near-field spectroscopy: Dependence of tip apex angle
✍ Scribed by Young-Jun Yu; Haneol Noh; Mun-Heon Hong; Heung-Ryoul Noh; Yasuhiko Arakawa; Wonho Jhe
- Publisher
- Elsevier Science
- Year
- 2006
- Tongue
- English
- Weight
- 766 KB
- Volume
- 267
- Category
- Article
- ISSN
- 0030-4018
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✦ Synopsis
We fabricated axicon microlenses on a single-mode bare optical fiber by using selective chemical etching technique. By varying the concentration and mixture ratios of etching solutions, we could make axicon microlenses with different apex angles (118°, 107°and 90°). We measured the illumination and collection efficiency of these microlenses by both objective-lens imaging and near-field photoluminescence (PL) spectroscopy of semiconductor quantum dots with respect to the distance between the sample and the axicon lens probe. We found that axicons with 118°and 107°[90°] apex angle tend to exhibit the laser focusing spot sizes of about 406 and 478 nm [382 nm] and maintain the high [slightly low] collection PL intensity with the distance between the sample and the axicon probe.