High‐Speed GaN‐Based 405 nm Violet Superluminescent Diode with Tilted Facet for Visible Light Communications

Abstract

Visible light communication (VLC) based on superluminescent diode (SLD) is a promising technology with great potential for future 6G optical wireless network. In this work, a 405 nm violet SLD device is fabricated with an 8° tilted facet at one end of the waveguide based on InGaN/GaN quantum wells. The device has an optical power of 14.67 mW under continuous‐wave operation. The full width at half maximum (FWHM) of the SLD at 400 mA is 12.52 nm, which is significantly larger than that in a violet laser diode (LD). Using the SLD as transmitter in VLC system, a high data transmission rate of 3.299 Gbps has been achieved using the discrete multiple tone (DMT) modulation. The corresponding bit error ratio (BER) is measured to be 1.67 × 10−3, which satisfies the forward error correction (FEC) threshold of 3.8 × 10−3. The results suggest that such device can be used as a promising light source for VLC and light fidelity (LiFi) applications.