Absorption rates Chemical vapor deposition Co-doped Dopant concentrations Doped fiber Erbium Erbium ion Fabrication Fiber lasers Glass modifiers Graphene Modified chemical vapor depositions Multiwavelength Nonlinear coefficient Nonlinear effect Nucleating agents Optical pumping Output power Passively Q-switched Potential applications Power levels Pulse energies Pulsed fiber lasers Pulsed laser sources Pulsewidths Pump power Repetition rate Saturable absorbers Short pulse Solution doping