Wavelength-Offset Filtering in Optical OFDM IMDD Systems Using Directly Modulated DFB Lasers

In optical OFDM (OOFDM) intensity-modulation and direct-detection (IMDD) single-mode fibre transmission systems using directly modulated DFB lasers (DMLs), wavelength-offset optical filtering considerably improves extinction ratios of OOFDM signals. However, optical filter-induced group delays bring about OOFDM signal spectrum distortions. Detailed investigations show that group delays associated with super Gaussian optical bandpass filters (OBPFs) significantly reduce both the dispersion tolerance and achievable optical power budget (OPB) of the system. To solve such a challenge, two simple approaches are proposed including combined optical filtering by using a ring resonator filter after a super Gaussian OBPF, and cascaded optical filtering by using multi-stage ring resonator filters. It is shown that, by optimizing ring resonator filter parameters, the proposed approaches can completely eliminate the filter group delay effect and enable 7 dB OPB improvements.

[1]  J L Wei,et al.  Experimental demonstration of a record high 11.25Gb/s real-time optical OFDM transceiver supporting 25km SMF end-to-end transmission in simple IMDD systems. , 2010, Optics express.

[2]  T. Strasser,et al.  Dispersion penalty measurements of narrow fiber Bragg gratings at 10 Gb/s , 1998, IEEE Photonics Technology Letters.

[3]  Sze Yun Set,et al.  Removal of the dispersion limitations in FBG filters using a thin-film based allpass device , 2003, OFC 2003 Optical Fiber Communications Conference, 2003..

[4]  H J Shaw,et al.  All-single-mode fiber resonator. , 1982, Optics letters.

[5]  P. Krehlik,et al.  Optimisation of narrowband optical filters for 10 Gbit/s directly modulated laser transmitters , 2010 .

[6]  M. Teich,et al.  Fundamentals of Photonics , 1991 .

[7]  Ting Wang,et al.  1.2 Tb/s symmetric WDM-OFDMA-PON over 90km straight SSMF and 1∶32 passive split with digitally-selective ONUs and coherent receiver OLT , 2011, 2011 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference.

[8]  M. Tilsch,et al.  Experimental demonstration of thin-film dispersion compensation for 50-GHz filters , 2003, IEEE Photonics Technology Letters.

[9]  X. Q. Jin,et al.  The Influence of Directly Modulated DFB Lasers on the Transmission Performance of Carrier-Suppressed Single-Sideband Optical OFDM Signals Over IMDD SMF Systems , 2009, Journal of Lightwave Technology.

[10]  Jian H. Zhao,et al.  Optical Filter Design and Analysis: A Signal Processing Approach , 1999 .

[11]  O. Schwelb,et al.  Transmission, group delay, and dispersion in single-ring optical resonators and add/drop filters-a tutorial overview , 2004, Journal of Lightwave Technology.

[12]  R.P. Giddings,et al.  Semiconductor Optical Amplifier-Enabled Intensity Modulation of Adaptively Modulated Optical OFDM Signals in SMF-Based IMDD Systems , 2009, Journal of Lightwave Technology.

[13]  Jian H. Zhao,et al.  Optical Filter Design and Analysis , 1999 .

[14]  Ł. Śliwczyński.  Resolving group delay of narrowband optical filters from their transmission characteristics , 2009 .

[15]  M. Premaratne,et al.  Laser RIN and linewidth requirements for direct detection optical OFDM , 2008, 2008 Conference on Lasers and Electro-Optics and 2008 Conference on Quantum Electronics and Laser Science.

[16]  J.M. Tang,et al.  30-gb/s signal transmission over 40-km directly modulated DFB-laser-based single-mode-fiber links without optical amplification and dispersion compensation , 2006, Journal of Lightwave Technology.

[17]  Kung-Li Deng,et al.  A 1024-channel fast tunable delay line for ultrafast all-optical TDM networks , 1997, IEEE Photonics Technology Letters.

[18]  David Piehler.  Implementing high [> 2048] split ratios in any PON , 2011, 2011 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference.

[19]  K. Shore,et al.  High-speed transmission of adaptively modulated optical OFDM signals over multimode fibers using directly Modulated DFBs , 2006, Journal of Lightwave Technology.

[20]  G. Lenz,et al.  Optical all-pass filters for phase response design with applications for dispersion compensation , 1998, IEEE Photonics Technology Letters.

[21]  R P Giddings,et al.  Significant improvements in optical power budgets of real-time optical OFDM PON systems. , 2010, Optics express.

[22]  J.M. Tang,et al.  7dB optical power budget improvements of 11.25Gb/s optical OFDM PON systems using optical filters , 2011, 2011 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference.

[23]  D. C. Agrawal.  Fibre Optic Communication , 2005 .

[24]  Ioannis Tomkos,et al.  Performance evaluation and improvement methods for low-driving voltage transmitters in long reach PONs , 2011, 2011 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference.

[25]  Maria C. Yuang,et al.  2.1-Tb/s·km OFDM long-reach PON transmission using a cost-effective electro-absorption modulator , 2011, 2011 Optical Fiber Communication Conference and Exposition and the National Fiber Optic Engineers Conference.

[26]  B. Charbonnier,et al.  Adaptive Loading Algorithm Implemented in AMOOFDM for NG-PON System Integrating Cost-Effective and Low-Bandwidth Optical Devices , 2009, IEEE Photonics Technology Letters.