DocumentCode :
1206473
Title :
Special erbium fiber amplifiers for short pulse switching, lasers, and propagation
Author :
Islam, M.N. ; Rahman, L. ; Simpson, J.R.
Author_Institution :
Dept. of Electr. Eng. & Comput. Sci., Michigan Univ., Ann Arbor, MI, USA
Volume :
12
Issue :
11
fYear :
1994
fDate :
11/1/1994 12:00:00 AM
Firstpage :
1952
Lastpage :
1962
Abstract :
We show that specially tailored erbium-doped fiber amplifiers (EDFA´s) can be useful for short-pulse soliton lasers, switching, and propagation. EDFA properties include group-velocity dispersion, birefringence, doping level, and doping distribution; and changing each of these properties enables novel applications. Polarization-maintaining EDFA´s can Re used in erbium-doped fiber lasers to avoid intensity-dependent or temperature-dependent state of polarization. We have demonstrated a passively mode-locked erbium-doped fiber laser that generates nearly transform-limited 320 fs pulses with 40 pJ energy using a polarization-maintaining EDFA near the zero dispersion wavelength and a bulk InGaAsP saturable absorber. Moderately birefringent EDFA´s can be used to control the walkoff and interaction between orthogonally polarized solitons in all-optical switches. For example, through numerical simulations, we design an all-optical cascadable logic gate with a fanout of 2.7 and energy contrast of 5.5 based on interactions in a soliton period long EDFA. Furthermore, distributed EDFA´s can be used for long-distance soliton propagation to shepherd the pulse using bandwidth-limited gain. For picosecond soliton pulses, we show that soliton self-frequency shift and Gordon-Hans effects limit propagation to below 100 km even for low-dispersion fibers. Bandwidth-limited amplification in EDFA may counteract frequency shift due to the soliton self-frequency shift, while frequency filters may suppress the Gordon-Hans effect. Also, because the gain spectral profile for the three-level EDFA changes with pump intensity, complications arise from pump attenuation, and the corresponding changes in the gain spectral profile along the length of the fiber
Keywords :
birefringence; erbium; fibre lasers; laser mode locking; optical fibre communication; optical fibre dispersion; optical fibre filters; optical fibre polarisation; optical logic; optical pumping; optical saturable absorption; optical solitons; optical switches; 100 km; 320 ps; 40 pJ; Gordon-Hans effect; all-optical cascadable logic gate; all-optical switches; bandwidth-limited gain; birefringence; bulk InGaAsP saturable absorber; doping distribution; doping level; erbium fiber amplifiers; erbium-doped fiber amplifiers; group-velocity dispersion; intensity-dependent; lasers; long-distance soliton propagation; nearly transform-limited pulses; passively mode-locked; polarization-maintaining EDFA´s; propagation; short pulse switching; short-pulse soliton lasers; temperature-dependent; zero dispersion wavelength; Birefringence; Doping; Erbium; Erbium-doped fiber amplifier; Erbium-doped fiber lasers; Laser mode locking; Optical fiber polarization; Optical pulses; Pulse amplifiers; Solitons;
fLanguage :
English
Journal_Title :
Lightwave Technology, Journal of
Publisher :
ieee
ISSN :
0733-8724
Type :
jour
DOI :
10.1109/50.336060
Filename :
336060
Link To Document :
بازگشت