Far-Field Imaging for Direct Visualization of Light Interferences in GaAs Nanowires
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- 作者：Rachel Grange ; Gerald Br枚nstrup ; Michael Kiometzis ; Anton Sergeyev ; Jessica Richter ; Christian Leiterer ; Wolfgang Fritzsche ; Christoph Gutsche ; Andrey Lysov ; Werner Prost ; Franz-Josef Tegude ; Thomas Pertsch ; Andreas T眉nnermann ; Silke Christiansen
- 刊名：Nano Letters
- 出版年：2012
- 出版时间：October 10, 2012
- 年：2012
- 卷：12
- 期：10
- 页码：5412-5417
- 全文大小：332K
- 年卷期：v.12,no.10(October 10, 2012)
- ISSN：1530-6992
文摘
The optical and electrical characterization of nanostructures is crucial for all applications in nanophotonics. Particularly important is the knowledge of the optical near-field distribution for the design of future photonic devices. A common method to determine optical near-fields is scanning near-field optical microscopy (SNOM) which is slow and might distort the near-field. Here, we present a technique that permits sensing indirectly the infrared near-field in GaAs nanowires via its second-harmonic generated (SHG) signal utilizing a nonscanning far-field microscope. Using an incident light of 820 nm and the very short mean free path (16 nm) of the SHG signal in GaAs, we demonstrate a fast surface sensitive imaging technique without using a SNOM. We observe periodic intensity patterns in untapered and tapered GaAs nanowires that are attributed to the fundamental mode of a guided wave modulating the Mie-scattered incident light. The periodicity of the interferences permits to accurately determine the nanowires鈥?radii by just using optical microscopy, i.e., without requiring electron microscopy.