The Spectrum of Erbium IV.

Kiyoshi Murakawa, Shigeki Suwa

叶薇薇 YE Wei-wei, 房鸿 FANG Hong, 刘承香 Liu Chengxiang +3 more

The on near Gaussian-shaped spectrum Erbium-doped fiber super-flourescent source was studied.The self-coherence function of Gaussian-shaped spectrum and the change of mean wavelength under different temperatures were theoretically analyzed.Using the double-pass forward configuration,the Gaussian-shaped spectrum was obtained with certain Erbium-doped fiber length.Meanwhile,pump powers could be adjusted to optimize the intrinsic thermal coefficient of Erbium-doped fiber.Finally,under the condition with erbium-doped fiber length of 10.05 m,LD power of 172 mW,the whole optical path(except pumping LD and the driving) in the environmental temperature from-40 ℃ to 60 ℃,the near Gaussian-shaped spectrum Erbium-doped fiber source with 66.651 ppm mean wavelength stability was obtained.

Shubin Yan, Xiaoqian Wang, Ma Kezhen +3 more

Using CO2laser metal method process the top of erbium-doped tapered fiber, which formed by stretching a standard optical fiber (SMF-125) while heating it with a hydrogen flame. The top of tapered fiber formed erbium-doped microsphere cavity with higher spherical by its surface tension when heating is stopped. The size of erbium-doped microsphere is 21µm. The position of erbium-doped microsphere is accurately adjusted between the pump power and monochromatic spectrometer so that it can be easily excited by 980 nm and 1480 nm infrared light. Excited erbium ions produce energy level transition and a number of sharp transmission spectrums are observed around the center wavelength of 1550nm. It expanded the spectrum wide and proved the frequency selection role of micro-cavity. Further analysis of the experimental results, we obtained the quality factor Q=4.4×108through calculating the transmission spectrum which is consistent with the theoretical value largely.

Louis C. Marquet, W. E. Behring

Hirotaka Ono, Makoto Yamada, Kentaro Ichii +1 more

The method for estimating the gain coefficient spectrum of an erbium-doped fiber (EDF) is proposed and demonstrated experimentally. The method employs a net gain-loss measurement that uses the 4I(13/2) level pumping of the EDF and the McCumber relation. A formula used to obtain the quotient of the gain and loss coefficient from the net gain-loss measurement is derived to determine the parameter in the McCumber relation. It is confirmed that the gain coefficient spectrum of an EDF estimated with the method coincides with the value estimated using a conventional net gain-loss measurement that employs the 4I(11/2) level pumping. The method is successfully applied to an erbium/ytterbium-doped fiber, for which it is impossible to perform a conventional net gain-loss measurement with pumping at the 4I(11/2) level of erbium ions because of the absorption transition of ytterbium ions from 2F(7/2) to 2F(5/2) levels.

W F MEGGERS