System-Performance Analysis of Optimized Gain-Switched Pulse Source Employed in 40- and 80-Gb/s OTDM Systems

The development of ultrashort optical pulse sources, exhibiting excellent temporal and spectral profiles, will play a crucial role in the performance of future optical time division multiplexed (OTDM) systems. In this paper, we demonstrate the difference in performance in 40- and 80-Gb/s OTDM systems between optical pulse sources based on a gain-switched laser whose pulses are compressed by a nonlinearly and linearly chirped fiber Bragg grating. The results achieved show that nonlinear chirp in the wings of the pulse leads to temporal pedestals formed on either side of the pulse when using the linearly chirped grating, whereas with the nonlinearly chirped grating, pedestals are essentially eliminated. In an OTDM system, these pedestals cause coherent interaction between neighboring channels, resulting in intensity fluctuations that lead to a power penalty of 1.5 dB (40 Gb/s) and 3.5 dB (80 Gb/s) in comparison to the case where the nonlinearly chirped grating is used. Simulations carried out with the aid of Virtual Photonics Inc. verify the results achieved.

[1]  N. Onodera,et al.  Nearly transform-limited pulse (3.6 ps) generation from gain-swtiched 1-55/spl mu/m distributed feeback laser by using fibre compression technique , 1993 .

[2]  L. Barry,et al.  Optimized pulse source employing an externally injected gain-switched laser diode in conjunction with a nonlinearly chirped grating , 2006, IEEE Journal of Selected Topics in Quantum Electronics.

[3]  H. F. Liu,et al.  Method of generating nearly transform-limited pulses from gain-switched distributed-feedback laser diodes and its application to soliton transmission. , 1992, Optics letters.

[4]  I. White,et al.  The effects of pedestal suppression on gain-switched laser sources for 40 Gbit/s OTDM transmission , 1997, Conference Proceedings. LEOS '97. 10th Annual Meeting IEEE Lasers and Electro-Optics Society 1997 Annual Meeting.

[5]  Y. Ogawa,et al.  160-gb/s OTDM signal source with 3R function utilizing ultrafast mode-locked laser diodes and modified NOLM , 2005, IEEE Photonics Technology Letters.

[6]  Benn C. Thomsen,et al.  Complete characterization of ultrashort pulse sources at 1550 nm , 1999 .

[7]  K. Lau.  Gain switching of semiconductor injection lasers , 1988 .

[8]  L. Barry,et al.  Optimized pulse source for 40-Gb/s systems based on a gain-switched laser diode in conjunction with a nonlinearly chirped grating , 2005, IEEE Photonics Technology Letters.

[9]  Johannes Skaar,et al.  Design and characterization of finite-length fiber gratings , 2003 .

[10]  Michalis N. Zervas,et al.  An efficient inverse scattering algorithm for the design of nonuniform fiber Bragg gratings , 1999 .

[11]  Liam P. Barry,et al.  A High-Speed Optical Star Network Using TDMA and All-Optical Demultiplexing Techniques , 1996, IEEE J. Sel. Areas Commun..

[12]  R. Boittin,et al.  Tunable transform-limited pulse generation using self-injection locking of an FP laser , 1993, IEEE Photonics Technology Letters.

[13]  Andrew D. Ellis,et al.  Optical time division multiplexing: systems and networks , 1994, IEEE Communications Magazine.

[14]  Amir Rosenthal,et al.  Inverse scattering algorithm for reconstructing strongly reflecting fiber Bragg gratings , 2003 .

[15]  Polina Bayvel,et al.  Compact and fully-packaged fibre grating laser-based RZ pulse source for 40 Gbit/s OTDM transmission systems , 2001, Proceedings 27th European Conference on Optical Communication (Cat. No.01TH8551).

[16]  P. Bayvel,et al.  Fibre grating laser-based RZ pulse source for 40 Gbit/s OTDM transmission systems , 2001 .

[17]  Zhaoyang Hu,et al.  Extinction ratio improvement by strong external light injection and SPM in an SOA for OTDM pulse source using a DBR laser diode , 2003, IEEE Photonics Technology Letters.

[18]  Dug Young Kim,et al.  Timing jitter reduction of gain-switched DFB laser by external injection-seeding , 1996 .

[19]  K. Taira,et al.  Subpicosecond pulse generation using an electroabsorption modulator and a double-stage pulse compressor , 2003, IEEE Photonics Technology Letters.

[20]  L. Barry,et al.  Performance issues associated with WDM optical systems using self-seeded gain switched pulse sources due to mode partition noise effects , 2002, IEEE Photonics Technology Letters.

[21]  K. Suzuki,et al.  Generation of transform limited gain-switched DFB-LD pulses <6 ps with linear fibre compression and spectral window , 1991 .

[22]  Paul Gunning,et al.  Gainswitched DFB laser diode pulse source using continuous wave light injection for jitter suppression and an electroabsorption modulator for pedestal suppression , 1996 .

[23]  John M. Dudley,et al.  Complete characterization of terahertz pulse trains generated from nonlinear processes in optical fibers , 2001 .

[24]  M. Nakazawa,et al.  Solitons for breaking barriers to terabit/second WDM and OTDM transmission in the next millennium , 2000, IEEE Journal of Selected Topics in Quantum Electronics.

[25]  H. F. Liu,et al.  Experimental demonstration of compression of dispersed optical pulses by reflection from self-chirped optical fiber Bragg gratings. , 1994, Optics letters.

[26]  M. Saruwatari,et al.  All-optical signal processing for terabit/second optical transmission , 2000, IEEE Journal of Selected Topics in Quantum Electronics.

[27]  Rick Trebino,et al.  Measuring ultrashort laser pulses in the time-frequency domain using frequency-resolved optical gating , 1997 .

[28]  A.M. Clarke,et al.  Generation of widely tunable picosecond pulses with large SMSR by externally injecting a gain-switched dual laser source , 2004, IEEE Photonics Technology Letters.