Study of techniques for efficient nonlinear frequency conversion of fibre lasers to the visible wavelength band

Scaling laser power in the visible band remains as one of the most significant challenges facing laser scientists, motivated by the needs of a growing number of applications in areas such laser processing of materials and medicine. Traditional methods for accessing this wavelength regime are not compatible with operation at high power levels and so a different approach is needed. This project will investigate a new strategy for generating kilowatt-class laser power in the visible band by combining the power-scaling advantages of cladding-pumped fibre lasers in the near-infrared band with novel nonlinear frequency conversion schemes. The approach offers the prospect of unprecedented wavelength coverage across the entire visible wavelength band at high power levels and with high overall efficiency. The project will involve a detailed study into the physics of frequency-converted fibre lasers to establish a power scaling strategy and to determine the fundamental limits. It is anticipated that development of strategies to suppress unwanted nonlinear processes in the fibre laser and to mitigate thermal effects due to residual heating in optical components will be important aspects of the project. The overall ambition of the project will be a new generation of visible lasers boasting levels of performance well beyond the current state-of-the-art for use in industrial laser processing.