Sains Malaysiana 30: 187-194 (2001)                                                                           Sains Fizis dan Gunaan /

Physical and Applied Sciences

Self-Saturation of Amplified Spontaneous Emission

in a Fiber Amplifer

M.A. Mahdi, S. Thirumeni, P. Poopalan

S. Selvakennedy, F.R. Mahmad Adikan H. Ahmad

Telekom Malaysia Photonics Research Center

Department of Physics, University of Malaya

50603 Kuala Lumpur, Malaysia

ABSTRAK

Kebergantungan keupayaan penguat gentian optik berdop erbium terhadap kesan tepuan-diri penguat telah dikaji dengan cara penalaan panjang gelombang pam berlebar jalur 5 nm terpusat pada panjang gelombang 980 nm. Gandaan dan angka hingar menunjukkan kemerosotan pada panjang gelombang serapan pam puncak yang juga menunjukkan kesan tertinggi terhadap ketepuan sendiri. Dibuktikan secara eksperimen bahawa dengan menala panjang gelombang pam ke nilai yang menjauhi nilai serapan pam puncak, peningkatan sebanyak 1 -2 dB dalam penukaran pam kepada isyarat diperoleh. Kesan tepuan-diri penguat juga bergantung kepada panjang gelombang isyarat dan gandaan tinggi serta kemerosotan angka hingar diperoleh pada jalur 1530 nm (±5 nm).

ABSTRACT

The dependence of erbium-doped fiber amplifier (EDFA) performance on amplifier self-saturation is studied by tuning the pump wavelength over a 5 nm band centered at 980 nm. Gain and noise figure are degraded at the peak pump absorption wavelength, which shows the strongest effect of amplifier self-saturation. It is shown experimentally that tuning the pump wavelength away from the peak pump absorption provides 1 -2 dB improvement in pump­ to-signal conversion. The effect of amplifier self-saturation is also dependent on the signal wavelength where high gain and noise figure penalties are obtained at 1530 nm (± 5 nm) band.

RUJUKAN/REFERENCES

Desurvire, E. 1992. Analysis of gain difference between forward- and backward­pumped erbium-doped fiber amplifiers in the saturated regime. IEEE Photon. Technol. Lett. 4(7): 711-714.

Desurvire, E., Zyskind, J. L. & Giles, C. R. 1990. Design optimization for efficient erbium-doped fiber amplifiers. IEEE J. of Lightwave Tech. 8(11): 1730-1741.

Liu, C-K., Jou, J-J. & Lai, F-Shun. 1995. Second-order harmonic distortion and optimal fiber length in erbium-doped fiber amplifiers. IEEE Photon. Technol. Lett., 7(12): 1412-.1414

Myslinski, P., Nguyen, D. & Chrostowski, J. 1997. Effects of concentration on the performance of erbium-doped fiber amplifiers. IEEE J. of Lightwave Technol. 15(11): 112-120.

Park, S. Y., Kim, H. K., Park C. S. & Shin, S. Y. 1995. Doped fiber length and pump power of gain-flattened EDFAs. Electron. Lett. 32(23): 2161-2162.

Pedersen, B. Chirravuri, J. & Miniscalco, W. J. 1992. Gain and noise figure properties of small-signal erbium-doped fiber amplifiers pumped in the 980-nm band. IEEE Photon. Technol. Leu. 4(6): 556-558.

Percival, M., Cole, S., Cooper, M., Craig-Ryan,V., Ellis, A. D., Rowe, C. J. & Stallard, W. A. 1991. Erbium-doped fiber amplifier with constant gain for pump wavelengths between 966 and 1004 nm. Electron. Leu. 27(14): 1266-1268.

Suzuki, K., Kimura, Y. and Nakazawa, M. 1989. Pumping wavelength dependence on gain factor of 0.98  μm pumped Er3+ fiber amplifier. App. Phys. Lett. 55(25): 2573-2575.

Visser, T. D., Blok, H., Demeulenaere, B. & Lenstra, D. 1997. Confinement factors and gain in optical amplifiers. IEEE J. of Quantum Electron. 33(10): 1763-1766.

Yadlowsky, M. J. & Button, L. J. 1998. Pump-mediated inhomogenous effects in EDFAs and their impact on gain spectral modelling. Proc. of Optical Fiber Communication Conference, San Jose.