High Peak-power GaN Semiconductor Laser for Underwater Thermal Sensing

<p dir="ltr">Elucidation of vertical temperature profiles in water columns drives innovation for defence applications and increases our understanding of the natural aquatic environment; this encompasses the optimisation of underwater communication and object detection, as well as assisting with accurate prediction of the climatic conditions in our oceans. Here, we propose a novel approach to achieving this vision through the implementation of a compact, economical, and electrically efficient GaN semiconductor laser. This device is designed to emit short, high peak powered pulses at rapid repetition rates. To ensure our aspiration is appropriate for subsurface temperature measurements, various spectral and intensity characteristics of this coherent source were examined.</p><p dir="ltr">Compellingly, this single optical emitter is capable of sustaining 20 A pulses within the order of nanoseconds, generating peak power upwards of 25 W. In this regime, our simulation reveals that the characteristically broad lasing spectrum of semiconductor devices does not disturb the accuracy of vertical temperature profiling. Further, a fascinating potential lies in the projected deployment of this technology in a variety of vehicles, including drones and underwater automobiles. The accessibility of this prognosis is highlighted in the durable, robust, and light weight nature of our configuration, built upon a semiconductor laser system. In addition, these compact devices boast high power efficiency, providing a perfect solution to various attenuation effects, destroying the barrier to deep sea sensing; allowing this simple technology to pioneer unparalleled insights into our natural waterways.</p>