https://scholars.lib.ntu.edu.tw/handle/123456789/607063
標題: | Ultrafast 2 × 2 green micro-LED array for optical wireless communication beyond 5 Gbit/s | 作者: | LIN G.-R KUO H.-C CHENG C.-H WU Y.-C HUANG Y.-M LIOU F.-J LEE Y.-C. GONG-RU LIN |
關鍵字: | Bandwidth;Capacitance;Electric fields;Gallium nitride;Light emitting diodes;Modulation;Optical communication;Orthogonal frequency division multiplexing;Sapphire;Semiconductor quantum wells;Signal encoding;Signal to noise ratio;Bit error ratios;Discrete multi-tone;Led array;Lightemitting diode;Micro-LED arrays;Optical-wireless communications;Quantum-confined Stark effect;Signal to noise (S/N) ratios;Transistor outlines;Ultra-fast;III-V semiconductors | 公開日期: | 2021 | 卷: | 9 | 期: | 10 | 起(迄)頁: | 2077-2087 | 來源出版物: | Photonics Research | 摘要: | A green 2 × 2 micro light-emitting diode (μ-LED) array with nanostructured grating patterns grown on a semipolar (20-21)-oriented gallium nitride (GaN) buffered layer on (22-43)-oriented sapphire substrate is specially transistor-outline can (TO-can) packaged with a sub-miniature-A (SMA) connector for high-speed data communication beyond 5 Gbit/s. Through a specific design for suppressing the quantum-confined Stark effect (QCSE) in the green 2 × 2 μ-LED array with a low polarization-related electric field and flat quantum well band diagram, the green 2 × 2 μ-LED array exhibits a turn-on voltage of 2.5 V and output power of 0.3 mW at 1 A/cm2. The green 2 × 2 μ-LED array also reveals a wavelength shift from 543 nm to 537 nm smaller than that of conventional devices grown on c-plane buffered GaN substrate due to the inhibited QCSE. The 50 μm emission aperture of the green 2 × 2 μ-LED array ensures a lower capacitance for a larger -3 dB modulation bandwidth, which exhibits -1 dB power compression at a larger bias under high-speed operation, as it is less affected by the high resistance of the single μ-LED element. With a specific TO-can+SMA package, the green 2 × 2 μ-LED array exhibits maximal data rates exceeding 1.5 Gbit/s for the non-return-to-zero on-off keying format and beyond 5.02 Gbit/s for the bit-loaded discrete multitone (BL-DMT) format, which is very promising for optical wireless communication. As the sampling rate increases from 4 GSa/s to 16 GSa/s, the μ-LED array's received signal-tonoise ratio (SNR) improves dramatically from 15.4 dB to 12.2 dB. The SNR remains about 15.4 dB, with a matching bit-error ratio (BER) of 2.7 × 10-3, whereas the 10-fold oversampling of the eight-ray quadrature amplitude modulation orthogonal frequency-division multiplexing (8-QAM OFDM) data stream with 16 GSa/s appears to reduce the SNR by -3 dB, resulting in a decoded BER of 3.3 × 10-3. The green 2 × 2 μ-LED array has demonstrated greater potential in data transmission beyond 5 Gbit/s using the BL-DMT algorithm for future applications in domains of visible light communication or optical wireless communication when packaged with handed mobile devices. ? 2021 Chinese Laser Press. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114778851&doi=10.1364%2fPRJ.437689&partnerID=40&md5=0980069f45e042a9917226137edfa146 https://scholars.lib.ntu.edu.tw/handle/123456789/607063 |
ISSN: | 23279125 | DOI: | 10.1364/PRJ.437689 |
顯示於: | 電機工程學系 |
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