Title :
Erbium-doped fiber amplifier second-order distortion in analog links and electronic compensation
Author :
Kuo, C.Y. ; Bergmann, E.E.
Author_Institution :
AT&T Bell Lab., Breinigsville, PA, USA
Abstract :
The authors study the second-order distortion when an erbium-doped fiber amplifier (EDFA) is used to amplify the analog optical AM cable TV (CATV) multiple carrier signal from a directly modulated distributed feedback (DFB) semiconductor laser. Experimentally, it was seen that this second order distortion depends critically on the gain of the EDFA fiber amplifier. The authors attribute this distortion to the interaction between the frequency chirping of the DFB laser and the variable gain with wavelength of the amplifier. The authors describe an electronic predistorter that compensates the nonlinearity produced by the DFB-laser-EDFA combination. As a result, the high power advantage of the EDFA can be fully realized in spite of the potential for second-order distortion in the system.<>
Keywords :
cable television; erbium; fibre lasers; optical communication equipment; optical links; optical pumping; CATV; DFB diode lasers; analog links; analog optical AM cable TV; directly modulated; distributed feedback; electronic compensation; electronic predistorter; erbium-doped fiber amplifier; fibre amplifier gain; frequency chirping; multiple carrier signal; optical modulation; pump lasers; second-order distortion; Distributed feedback devices; Erbium-doped fiber amplifier; Erbium-doped fiber lasers; Laser feedback; Laser noise; Optical distortion; Optical feedback; Optical modulation; Semiconductor lasers; Stimulated emission;
Journal_Title :
Photonics Technology Letters, IEEE
