Novel nanoscale photoelectron and X-ray sources
Abstract/Contents
- Abstract
- We report a new optical near-field transducer comprised of a metallic nano-antenna extending from the ridge of a C-shaped metallic nano-aperture. Finite-difference time domain simulations predict that the C-aperture nano-tip (CAN-Tip) provides high intensity (650x), high optical resolution (~ [lambda]/60), and background-free near-field illumination at a wavelength of 980 nm. The CAN-Tip has an aperture resonance and tip antenna resonance which may be tuned independently, so the structure can be made resonant at ultraviolet wavelengths without being unduly small, which can be an ideal nano-optical source for the nano-photoelectron source. In the second part, we report a novel design for and first experimental demonstration of an array of nm-scale, controllable, photoelectron sources using helium ion beam milled 20 nm C-apertures. The apertures were designed and fabricated to resonate at 257 nm and coating with a thin-film photocathode while maintaining photonic resonance. We obtained beams of ~240 pA from each source with estimated emission areas of only 79.2 nm2 (1/e2). Such sources are badly needed for high throughput electron beam lithography and inspection. With far-field projection (> mm) of sub-20 nm photoelectron beams, applications open up in bio imaging, sensing, nano-metrology, and data storage. Lastly we apply the same unity magnification system to build a 3D differential phase contrast X-ray imaging system for identification of explosive materials in luggage. We aim to utilize an optically patterned photoelectron-excited X-ray source to circumvent difficulties of fabrication and power efficiency encountered when relying on conventional X-ray sources. I discuss how electron bombardment activated color centers provide a more efficient way to excite photoelectrons with lower photon energies.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2014 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Cheng, Yao-Te |
|---|---|
| Associated with | Stanford University, Department of Materials Science and Engineering. |
| Primary advisor | Brongersma, Mark L |
| Primary advisor | Hesselink, Lambertus |
| Thesis advisor | Brongersma, Mark L |
| Thesis advisor | Hesselink, Lambertus |
| Thesis advisor | Pease, R. (R. Fabian W.) |
| Advisor | Pease, R. (R. Fabian W.) |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Yao-Te Cheng. |
|---|---|
| Note | Submitted to the Department of Materials Science and Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2014. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2014 by Yao-Te Cheng
Also listed in
Loading usage metrics...