Automotive free-space optical communication at 1400nm
<p>Future vehicular transportation will use autonomous and semi-autonomous systems with, in part, the aim of significantly improving road safety. Implementing a reliable communication system that allows for the sharing of information between vehicles and their environment could improve computa...
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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2020
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| _version_ | 1826315943305805824 |
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| author | Farmer, J |
| author2 | O'Brien, D |
| author_facet | O'Brien, D Farmer, J |
| author_sort | Farmer, J |
| collection | OXFORD |
| description | <p>Future vehicular transportation will use autonomous and semi-autonomous systems with, in part, the aim of significantly improving road safety. Implementing a reliable communication system that allows for the sharing of information between vehicles and their environment could improve computational efficiency and facilitate collective pre-planning for arising situations. Optical Wireless Communication (OWC) is a promising candidate for a safe, reliable, and practical automotive communication system. </p>
<p>One of the major issues in the field of automotive OWC is the mitigation of ambient light, especially in the outdoor environment. In addition, maintaining a link in a dynamic environment and achieving high data rates over the distances required for automotive communication are crucial areas of current development. </p>
<p>This thesis describes the development of an optical communication system operating at 1400nm. The strong absorption of sunlight by water vapour at close to 1400nm creates a wavelength band with substantially lower ambient sunlight light noise than in the visible region. This noise benefit over the conventionally used visible range is explored in a link budget model, which compares the links at the different wavelengths. </p>
<p>A 1400nm link is then experimentally demonstrated using a custom-built hybrid LED. This provides 1400nm emission alongside visible emission, using a Quantum Dot based wavelength converter that is excited by the visible radiation. This provides simultaneous illumination and communication in the visible region of the optical spectrum and at 1400nm in a single, small form factor package. With this system, data rates of 1.75Mb/s at 1400nm and 41Mb/s at 450nm could be achieved. Using a second, dedicated 1400nm transmitter, developed using commercially available InGaAsP LEDs, a >4.5Mb/s 1400nm link could be facilitated over long ranges (1.25-5m) and outdoors in a high ambient light scenario.</p>
<p>Finally, consideration is given to the potential enhancement of the receiver side of a 1400nm link with the employment of a fluorescent concentrator (FC). 3D printing is explored for the fabrication of these FCs in the visible and the NIR range, with the possibility of new topologies and fluorescence properties being quickly prototyped and characterised. As a proof-of-concept for this new fabrication procedure, a visible FC with a signal gain of 4 could be demonstrated. In addition, the fabrication method was extended to PbS quantum dot based NIR FCs to be used within the receiver of the proposed 1400nm link system.
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| first_indexed | 2024-03-07T07:02:47Z |
| format | Thesis |
| id | oxford-uuid:24ef5846-ff18-4d30-8c79-d0822c204a41 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-12-09T03:35:18Z |
| publishDate | 2020 |
| record_format | dspace |
| spelling | oxford-uuid:24ef5846-ff18-4d30-8c79-d0822c204a412024-12-01T18:52:02ZAutomotive free-space optical communication at 1400nmThesishttp://purl.org/coar/resource_type/c_db06uuid:24ef5846-ff18-4d30-8c79-d0822c204a41Optical Free Space CommunicationEnglishHyrax Deposit2020Farmer, JO'Brien, D<p>Future vehicular transportation will use autonomous and semi-autonomous systems with, in part, the aim of significantly improving road safety. Implementing a reliable communication system that allows for the sharing of information between vehicles and their environment could improve computational efficiency and facilitate collective pre-planning for arising situations. Optical Wireless Communication (OWC) is a promising candidate for a safe, reliable, and practical automotive communication system. </p> <p>One of the major issues in the field of automotive OWC is the mitigation of ambient light, especially in the outdoor environment. In addition, maintaining a link in a dynamic environment and achieving high data rates over the distances required for automotive communication are crucial areas of current development. </p> <p>This thesis describes the development of an optical communication system operating at 1400nm. The strong absorption of sunlight by water vapour at close to 1400nm creates a wavelength band with substantially lower ambient sunlight light noise than in the visible region. This noise benefit over the conventionally used visible range is explored in a link budget model, which compares the links at the different wavelengths. </p> <p>A 1400nm link is then experimentally demonstrated using a custom-built hybrid LED. This provides 1400nm emission alongside visible emission, using a Quantum Dot based wavelength converter that is excited by the visible radiation. This provides simultaneous illumination and communication in the visible region of the optical spectrum and at 1400nm in a single, small form factor package. With this system, data rates of 1.75Mb/s at 1400nm and 41Mb/s at 450nm could be achieved. Using a second, dedicated 1400nm transmitter, developed using commercially available InGaAsP LEDs, a >4.5Mb/s 1400nm link could be facilitated over long ranges (1.25-5m) and outdoors in a high ambient light scenario.</p> <p>Finally, consideration is given to the potential enhancement of the receiver side of a 1400nm link with the employment of a fluorescent concentrator (FC). 3D printing is explored for the fabrication of these FCs in the visible and the NIR range, with the possibility of new topologies and fluorescence properties being quickly prototyped and characterised. As a proof-of-concept for this new fabrication procedure, a visible FC with a signal gain of 4 could be demonstrated. In addition, the fabrication method was extended to PbS quantum dot based NIR FCs to be used within the receiver of the proposed 1400nm link system. </p> |
| spellingShingle | Optical Free Space Communication Farmer, J Automotive free-space optical communication at 1400nm |
| title | Automotive free-space optical communication at 1400nm |
| title_full | Automotive free-space optical communication at 1400nm |
| title_fullStr | Automotive free-space optical communication at 1400nm |
| title_full_unstemmed | Automotive free-space optical communication at 1400nm |
| title_short | Automotive free-space optical communication at 1400nm |
| title_sort | automotive free space optical communication at 1400nm |
| topic | Optical Free Space Communication |
| work_keys_str_mv | AT farmerj automotivefreespaceopticalcommunicationat1400nm |