A Flat-Gain Double-Pass Amplifier with New Hafnia-Bismuth-Erbium Codoped Fiber

摘要

An efficient and compact double-pass optical fiber amplifier is demonstrated using a newly developed hafnia bismuth erbium co-doped fiber (HBEDF) as a gain medium.The HBEDF is fabricated using a modified chemical vapor deposition in conjunction with solution doping.The fiber has an erbium ion concentration of 12500ppm.At the optimum length of 0.5m,the HBEDF amplifier (HBEDFA) achieves a fiat gain of 26dB with a gain variation of less than 1.5dB within a wavelength region from 1530 to 1560nm when the input signal and pump power are fixed at-30dBm and 140mW,respectively.On the other hand,at the input signal power of-10dBm,the HBEDFA also achieves a fiat gain of 14,2 dB with a gain variation of less than 2.5 dB within a wide wavelength region from 1525 to 1570nm.Compared with the conventional zirconia erbium co-doped fiber based amplifier,the proposed HBEDFA obtains a more efficient gain and lower noise figure.For an input signal of-30dBm,the gain improvements of 6.2 dB and 4.8 dB are obtained at 1525 nm and 1540 nm,respectively.