Graded index immersion optics with application as solar concentrators
Abstract/Contents
- Abstract
- Axially Graded Index LEns (AGILE), as an effective non-tracking concentrator, was conceptualized, simulated, and fabricated. The results demonstrated how modes/optical power can be confined in a smaller volume in a high refractive index media and paved the way for a passive concentration system coupled to solar absorbers with optical and mechanical bonding, which saves PV (Photo-Voltaic) material cost, and provides space for cooling and circuitry. Most importantly, AGILE prototypes were fabricated in straightforward, inexpensive, and scalable processes. Simple to test and verify, back-to-back AGILEs demonstrated a concentration of up to 10 suns (geometric area ratio) and tracked the theoretical simulations. AGILE is a simple device that rests on fundamental laws and has the potential to greatly improve solar conversion systems by reducing cost, increasing efficiency, and providing a robust modular design with natural anti-reflection and encapsulation. The operational principle of the AGILE is based on the fact that the number of states of an optical aperture is proportional to the square of the Refractive Index (RI), which allows loss-free concentration by a factor of square of RI. Development of AGILE into a practical technology presented substantial challenges in material science and fabrication techniques. After exploring various techniques for making graded index and fabricating optical devices with glass bonding and curing of polymer films, high-quality optics were also fabricated using 3D printing and smoothing technique. A UV gel smoothing technique that can be used with commercial 3D printers (resolution of tens of microns) was conceptualized and developed, and the optical surfaces fabricated gave a rms (root mean square) surface roughness of around 2 nm. Optical components made using 3D printing including mirrors, lenses, and solar concentrator arrays were demonstrated and tested. 3D printing ushers in a new era in optical device fabrication. This 3D printing technique was also used to fabricate and demonstrate high concentration AGILEs of up to 10 suns. Ultimately, AGILE requires transparent, robust, and broadband transparent materials with RI (Refractive Index) gradually ranging from 1 to 3.5 and beyond. Evolution of the AGILE basic structure into a more sophisticated design will involve a robust lens top surface, an optimized side wall profile, and a radial as well as an axial index gradient with nano structuring to couple light from the concentrator to the solar cell. The AGILE fabrication process, once transferred as a commercially technology, has the potential to not only change the way we concentrate light (applications also in illumination, coupling, anti-reflection coatings, and displays), but also the economy and adoption of solar power.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2016 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Vaidya, Nina |
|---|---|
| Associated with | Stanford University, Department of Electrical Engineering. |
| Primary advisor | Solgaard, Olav |
| Thesis advisor | Solgaard, Olav |
| Thesis advisor | Dauskardt, R. H. (Reinhold H.) |
| Thesis advisor | Fan, Shanhui, 1972- |
| Advisor | Dauskardt, R. H. (Reinhold H.) |
| Advisor | Fan, Shanhui, 1972- |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Nina Vaidya. |
|---|---|
| Note | Submitted to the Department of Electrical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2016. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2016 by Nina Mukund Vaidya
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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