Experimental investigation of 16.6 Gbps SDM-WDM visible light communication based on a neural network receiver and tricolor mini-LEDs

High bandwidth series-biased green micro-LED array toward 6 Gbps visible light communication

In this Letter, a record modulation bandwidth of 1.31 GHz was achieved by a 10 µm c-plane green micro light emitting diode (micro-LED) at a current density of 41.4 kA/cm². Furthermore, by designing a series-biased 20 µm micro-LED with higher light output power, combined with an orthogonal frequency division multiplexing modulation scheme, a maximum data rate of 5.789 Gbps was achieved at a free-space transmission distance of 0.5 m. This work demonstrates the prospect of c-plane polar green micro-LED in ultrahigh-speed visible light communication, which is expected to realize a high-performance wireless system in the future.

Beyond 25 Gbps optical wireless communication using wavelength division multiplexed LEDs and micro-LEDs

In this Letter, high-speed optical wireless communication (OWC) with three light-emitting diodes (LED) and five micro-LEDs (μLEDs) is proposed as a proof-of-concept wavelength division multiplexing (WDM) system. It covers a wide spectrum from deep ultraviolet (UV) to visible light and thus could offer both visible light communication (VLC) and UV communication simultaneously. An aggregated data rate of up to 25.20 Gbps over 25 cm free space is achieved, which, to the best of our knowledge, is the highest data rate for LED-based OWC ever reported. Among them, the five μLEDs offer a data rate of up to 18.43 Gbps, which, to the best of our knowledge, is the highest data rate for μLED-based OWC so far. It shows the superiority and potential of μLEDs for WDM-OWC. Additionally, a data rate of 20.11 Gbps for VLC is achieved.

8.75 Gbps visible light communication link using an artificial neural network equalizer and a single-pixel blue micro-LED

Visible light communication (VLC) beyond 10 Gbps is an important characteristic that can support the future 6 G high-capacity requirements. On the one hand, in order to break the electro-optics (E-O) bandwidth limitation of the light-emitting diodes (LEDs), we fabricated two high-bandwidth (>gigahertz) single wetting layer micro-LEDs with 50 and 75 µm active regions. On the other hand, for mitigating the nonlinear effects of the VLC system, an artificial neural network equalizer is designed and implemented in offline digital signal processing. Both efforts lead to a breakthrough of data rates at a single VLC link. Using quadrature phase shift keying orthogonal frequency division multiplexing, the data rate of a 1.025 GHz VLC link based on a 75 µm micro-LED can reach 8.75 Gbps with a bit-error-ratio (BER) of 2.73×10^-3. In addition, the E-O characteristics and communication performances of micro-LED with two diameters are compared and discussed. To the best of our knowledge, the data rate of 8.75 Gbps is the highest record of the VLC link based on a single-pixel blue micro-LED with a BER within the forward error correction citation of 3.8×10^-3.

Visible Light Communication System Technology Review: Devices, Architectures, and Applications

Visible light communication (VLC) is an advanced, highly developed optical wireless communication (OWC) technology that can simultaneously provide lighting and high-speed wireless data transmission. A VLC system has several key advantages: ultra-high data rate, secure communication channels, and a lack of interference from electromagnetic (EM) waves, which enable a wide range of applications. Light-emitting diodes (LEDs) have been considered the optimal choice for VLC systems since they can provide excellent illumination performance. However, the quantum confinement Stark effect (QCSE), crystal orientation, carrier lifetime, and recombination factor will influence the modulation bandwidth, and the transmission performance is severely limited. To solve the insufficient modulation bandwidth, micro-LEDs (μ-LEDs) and laser diodes (LDs) are considered as new ideal light sources. Additionally, the development of modulation technology has dramatically increased the transmission capacity of the system. The performance of the VLC system is briefly discussed in this review article, as well as some of its prospective applications in the realms of the industrial Internet of Things (IoT), vehicle communications, and underwater wireless network applications.