Laser-based white-light source utilizing wavelength multiplexing for underwater high-speed wireless optical communication and high-fidelity illumination

We present a dual-purpose underwater white laser source (WLS) that simultaneously supports high-speed wireless optical communication and high-fidelity illumination. The WLS combines red, green, and blue laser diodes (RGB LDs) with a yellow diode-pumped solid-state laser (Y-DPSSL) through wavelength-division multiplexing (WDM). For a 2 m underwater wireless optical communication (UWOC) link, the RGB LDs modulated with 16-quadrature amplitude modulation discrete multitone (16-QAM DMT) achieve data rates of 4 Gbps, 6 Gbps and 6 Gbps, respectively. The corresponding bit error rates (BERs) of 3.66 × 10 −3 , 3.11 × 10 −3 and 3.49 × 10 −3 all fall below the forward error correction (FEC) threshold of 3.8 × 10 −3 , confirming the high speed of the communication system. When the Y-DPSSL is activated, its yellow-orange emission blends with the RGB light to produce high-fidelity white illumination, characterized by a correlated color temperature (CCT) of 6371 K, a color rendering index (CRI) of 79.5, Commission International de l’Eclairage (CIE) coordinates of (0.3963, 0.4499) and an illuminance of 7984 lux. A 24-color checker test yields a total color reproduction error of 13.36, further validating the WLS’s illumination performance. These results demonstrate the WLS’s capacity to deliver both underwater high-speed communication and high-fidelity illumination, highlighting its potential for integrated subsea applications.