Abstract: A dual wavelength pumping system and method have been developed to improve the efficiency of laser systems operating in the raid infrared region has been developed, in a conventional system the ions are excited from a ground state to an upper lasing state using a light pump. They then undergo a laser transition to leave the ion in a long lived post lasing excited state from which it eventually decays back to the ground state. In contrast they present system uses a first light pump to pump ions from the ground state to the post lasing state, and a second light pump to pump ions from the post lasing state to the upper lasing state. This system thus exploits the long lifetime of the post lasing state to enable it to become a virtual ground state for the second laser allowing continued cycling of ions between the upper lasing state and the post lasing state. A system using an Erbium, doped fiber generated a 3.5 ?m laser output with an average power of over 250 mW and an initial slope, efficiency of 25.

Abstract: A dual wavelength pumping system and method have been developed to improve the efficiency of laser systems operating in the raid infrared region has been developed, in a conventional system the ions are excited from a ground state to an upper lasing state using a light pump. They then undergo a laser transition to leave the ion in a long lived post lasing excited state from which it eventually decays back to the ground state. In contrast they present system uses a first light pump to pump ions from the ground state to the post lasing state, and a second light pump to pump ions from the post lasing state to the upper lasing state. This system thus exploits the long lifetime of the post lasing state to enable it to become a virtual ground state for the second laser allowing continued cycling of ions between the upper lasing state and the post lasing state. A system using an Erbium, doped fibre generated a 3.5 ?m laser output with an average power of over 250 mW and an initial slope, efficiency of 25.