Abstract
In an optical wireless communication system, the LEDs require high bandwidth to achieve data rates compare to RF communications. Therefore, it is preferred to use high current densities to drive the LED, even beyond its maximum efficiency point. Nevertheless, the LED is a self-heating device where part of the electrical power is converted to optical power and the rest into heat. This increment of temperature in the LED will reduce its optical power and efficiency, causing a degradation of the optical system SNR. Firstly, we start by deriving
the relationship between the LED voltage with its junction temperature using the Shockley equation. Then, we measure the forward voltage at different temperatures to prove a linear relation between them. The optical power, LED bandwidth, and efficiency can be calculated using the ABC parameters from the rate equation. Therefore, we propose a method to obtain these parameters by measuring the emitted optical power and its rise time when varying the driving current. Finally, the ABC parameters are calculated by solving an MMSE problem with the measurements previously done. The throughput of an optical wireless link depends on the efficiency and the LED bandwidth, thus it is temperature dependent. We calculate the degradation of the rate caused by the temperature increment.
the relationship between the LED voltage with its junction temperature using the Shockley equation. Then, we measure the forward voltage at different temperatures to prove a linear relation between them. The optical power, LED bandwidth, and efficiency can be calculated using the ABC parameters from the rate equation. Therefore, we propose a method to obtain these parameters by measuring the emitted optical power and its rise time when varying the driving current. Finally, the ABC parameters are calculated by solving an MMSE problem with the measurements previously done. The throughput of an optical wireless link depends on the efficiency and the LED bandwidth, thus it is temperature dependent. We calculate the degradation of the rate caused by the temperature increment.
Original language | English |
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Title of host publication | Physics and Simulation of Optoelectronic Devices XXXI |
Editors | Bernd Witzigmann, Marek Osinski, Yasuhiko Arakawa |
Publisher | SPIE |
Number of pages | 10 |
ISBN (Electronic) | 9781510659353 |
DOIs | |
Publication status | Published - 10 Mar 2023 |
Event | SPIE OPTO 2023 - San Francisco, United States Duration: 28 Jan 2023 → 3 Feb 2023 |
Publication series
Name | Proceedings of SPIE - The International Society for Optical Engineering |
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Volume | 12415 |
ISSN (Print) | 0277-786X |
ISSN (Electronic) | 1996-756X |
Conference
Conference | SPIE OPTO 2023 |
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Country/Territory | United States |
City | San Francisco |
Period | 28/01/23 → 3/02/23 |
Keywords
- Optical wireless communication (OWC)
- LED lighting
- forward voltage method
- IQE
- dIQE
- LED
- OWC