Spectral Irradiance Distribution in Underwater Light Field Generated by an LED Light Source

Artificial underwater illumination has a wide range of applications in coastal zone research, marine engineering, marine resource exploration and development, and marine ecological environment monitoring. In this article, the distribution of spectral irradiance has been discussed for an underwater light field generated by an underwater LED light source. Theoretical representations of the spectral irradiance have been derived according to physical principles and underwater spectral irradiance measurement have been accrued out along the optical axis of the light source and in the vertical plane perpendicular to the optical axis. Experimental results show that the spectral irradiance along the optical axis of the light source decays with respect to the distance, following the law of square attenuation and exponential attenuation. The irradiance in the vertical plane approximately matches the Gaussian distribution.