| 摘要 |
A very large more area active double clad optical waveguide (10) doped in the central core region (20) with Nd 3+ (19) at a concentration of at least 0.1 % by weight can be used to effectively amplify light at a wavelength of between 1050nm and 1120nm. At a doping concentration sufficient to provide a net optical absorption of at least 3dB/m for the pump light (12) at the wavelength of 795 to 815nm or 883 to 887nm, Nd 3+ operates under much lower inversion levels than Yb 3+ . Due to the lower inversion levels, the Nd 3+ doped waveguide is subject to reduced pump bleaching or photodarkening. The pump light (12) is guided by the second cladding (22) and the signal light (14) to be amplified is guided by the first cladding (21) with a very large mode area (15) of at least 500 square micrometer. |
