Theory of Pr/sup 3+/-doped fluoride fiber upconversion lasers

A thorough investigation of Pr/sup 3+/-doped fluoride fiber upconversion lasers at the blue, green, and red wavelengths has been conducted based on both numerical and analytical models. Many aspects of the blue laser system are studied including population inversion, pump absorption, and signal mode determination. The most important parameters in the blue laser are analyzed in detail. Based on the investigations, design optimization of the laser is discussed. Experimental results are also presented for the verification of the theoretical models.