碩士 / 國立臺北科技大學 / 光電工程系研究所 / 105 / With the speedy progress in underwater wireless optical communication (UWOC) system,increasing demands drive the requirements for long-range and high-speed underwater links. For the actual implementation of an UWOC system, long-range and highspeed underwater links are the key concerns of system designers. An UWOC system has numerous applications in oceanography, environmental monitoring, and underwater surveillance. Therefore, an UWOC system that employs a 488-nm blue light laser diode (LD) with high optical output power is anticipated to provide a long-range underwater link.
Light injection and optoelectronic feedback techniques had been adopted in different lightwave transport systems to improve the transmission performance. Nevertheless, these techniques have not yet been adopted to improve the transmission performance of the four-level pulse amplitude modulation (PAM-4) UWOC system. LD with light injection technique exhibits an enhancement in frequency response, and the optoelectronic feedback technique can further enhance the frequency response. Therefore, light injection and optoelectronic feedback techniques are attractive to provide a high-speed underwater link in a PAM-4 UWOC system.
In this thesis, a 16 Gb/s PAM-4 UWOC system based on 488-nm blue light LD with light injection and optoelectronic feedback techniques is proposed and experimentally demonstrated. Compared with non-return-to-zero (NRZ) signal, PAM-4 signal provides two bits in each symbol with the advantages of high transmission rate and less bandwidth requirement. PAM-4 transmission is thereby regarded as one of the key solutions for establishing a high-speed
UWOC system . Good bit error rate (BER) performance (offline processed by Matlab) and clear eye diagrams (measured in real-time) are achieved at a 10-m underwater operation by employing a 488-nm LD transmitter with light injection and optoelectronic feedback techniques.
| Identifer | oai:union.ndltd.org:TW/105TIT05124024 |
| Creators | Chun-Ming Ho, 何俊明 |
| Contributors | Hai-Han Lu, 呂海涵 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 0 |
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