Analysis of dual-end-pumped Nd3+-doped index-crossover gain guided–index antiguided fiber laser

• A dual-end-pumped Nd3+-doped IGG–IAG fiber laser is proposed.
• Expressions of threshold pump power and output laser power are obtained.
• Analysed the influence of the fiber laser parameters on threshold pump power.
• Pump power distribution in IGG–IAG fiber is more uniform than that of GG–IAG fiber.
• Output laser power of IGG–IAG fiber is higher than that of GG–IAG fiber.

A dual-end pumped Nd3+-doped index-crossover gain guided–index antiguided (IGG–IAG) fiber laser is analyzed in theory. Pump light propagation and output laser characteristics are both explored by solving the related rate equations. Simulation results show that pump power confined in the IGG–IAG fiber core is larger and more uniform than that of the gain-guided and index-antiguided(GG–IAG) fiber, and the optimum fiber length and the output power of the IGG–IAG fiber laser are both larger than that of GG–IAG fiber laser. The relationship between threshold pump power and doped concentration, fiber length, fiber radius is researched respectively. The analysis results give out a method for the optimal design of the IGG–IAG fiber laser.