Dual wavelength pumped laser system and method

摘要

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 μm laser output with an average power of over 250 mW and an initial slope, efficiency of 25.4% (previous system have only generates less than 10 mW of power with efficiencies of 3%).

主权项

1. A method for pumping a gain medium to generate a lasing transition of a lasing wavelength between an upper lasing state and a lower lasing state in the gain medium, the method comprising:
directing electromagnetic (EM) radiation of a first wavelength from a first pump source into the gain medium to excite ions in the gain medium from a ground state to a long lived excited state; and directing EM radiation of a second wavelength from a second pump source into the gain medium to excite ions in the gain medium from the long lived excited state to an upper state to create a population inversion between the upper lasing state and the lower lasing state to generate the lasing transition; wherein the lasing wavelength is longer than the second wavelength; and wherein the lasing transition is in the wavelength range of 3.2 μm to 3.9 μm.