OSA's Digital Library

Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 20, Iss. 26 — Dec. 10, 2012
  • pp: B21–B31
« Show journal navigation

Full-asynchronous gigabit-symmetric DPSK downstream and OOK upstream OCDMA-PON with source-free ONUs employing all-optical self-clocked time gate

Bo Dai, Satoshi Shimizu, Xu Wang, and Naoya Wada  »View Author Affiliations


Optics Express, Vol. 20, Issue 26, pp. B21-B31 (2012)
http://dx.doi.org/10.1364/OE.20.000B21


View Full Text Article

Acrobat PDF (1962 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

We propose an asynchronous gigabit-symmetric optical code division multiplexing access passive optical network (OCDMA-PON) in which optical network units (ONUs) are source-free. In the experiment, we demonstrate a duplex OCDMA system with a 50 km 10 Gbit/s/user 4-user DPSK-OCDMA downlink and a 50 km 10 Gbit/s/user 4-user OOK-OCDMA uplink and error-free duplex transmissions are achieved. Besides, we investigate an all-optical self-clocked time gate, which is used for the signal regeneration of decoded signals and ensures asynchronization in the up/downstream transmissions. Furthermore, we evaluate the power budget of the proposed duplex transmission.

© 2012 OSA

1. Introduction

In the PON, an ONU processes the conversion between optical signals and electrical signals at a user’s premise. The complexity of ONUs should be mitigated to reduce the cost of end users. To simplify the structure of ONUs, several remodulation schemes have been proposed in the different PONs. A 2.5 Gbit/s on-off keying (OOK) upstream transmitter was proposed for remodulation in a wavelength division multiplexing (WDM)-PON by directly modulating an FP laser which was injection-locked by a 10 Gbit/s DPSK downstream signal [7

7. W. Hung, C. K. Chan, L. K. Chen, and F. Tong, “An optical network unit for WDM access networks with downstream DPSK and upstream remodulated OOK data using injection-locked FP laser,” IEEE Photon. Technol. Lett. 15(10), 1476–1478 (2003). [CrossRef]

]. A wavelength remodulation scheme using DPSK formats in both downstream and remodulated upstream was demonstrated in a 10 Gbit/s DWDM-PON [8

8. C. W. Chow, “Wavelength remodulation using DPSK down-and-upstream with high extinction ratio for 10-Gb/s DWDM-passive optical networks,” IEEE Photon. Technol. Lett. 20(1), 12–14 (2008). [CrossRef]

]. In [9

9. J. Yu, M. F. Huang, D. Qian, L. Chen, and G. K. Chang, “Centralized lightwave WDM-PON employing 16-QAM intensity modulated OFDM downstream and OOK modulated upstream signals,” IEEE Photon. Technol. Lett. 20(18), 1545–1547 (2008). [CrossRef]

], a centralized lightwave remodulation scheme which employed a 10 Gbit/s quadrature amplitude modulation (16-QAM) downstream and a remodulated 2.5 Gbit/s OOK upstream was proposed in an orthogonal frequency-division multiplexing (OFDM)-WDM-PON.

In this paper, we extend our recent work [10

10. B. Dai, S. Shimizu, X. Wang, and N. Wada, “Full-asynchronous gigabit-symmetric OCDMA-PON with source-free ONUs based on DPSK downstream and remodulated OOK upstream links,” in 38th European Conference and Exhibition on Optical Communication (ECOC 2012), Amsterdam, the Netherlands, paper Mo.1.B.5 (2012).

] to show a full picture of an asynchronous gigabit-symmetric DPSK-downstream and remodulated OOK-upstream OCDMA-PON. The paper is organized as follows. In Section 2, we describe the proposed OCDMA-PON architecture. Then, we introduce an all-optical self-clocked time gate in Section 3, which is a key component used in the ONUs for signal regeneration. In Section 4, we show our experimental demonstration and results. Next, in Section 5, we investigate the performance improvement by employing self-clocked time gate and evaluate the power budget of the duplex transmission. Finally, the paper is summarized in Section 6.

2. OCDMA-PON architecture

At the ONU side, the multiplexed encoded signals are split into N branches by a power splitter. In each ONU, a corresponding decoder is used for decoding the signal. Correctly decoded signals are recovered into high-intensity peak pulses while incorrectly decoded signals remain low intensity, which produce multiple-access interference (MAI). The following signal regeneration process, where a time gate or a phase-preserving thresholder can be used, is to extract the correctly decoded signals and to suppress the MAIs. Then, the signals are separated into two branches. In one branch, the signal is demodulated and detected in the receiver. In the other branch, the signal is used for the upstream transmission. This upstream signal is further split into two. One is input into a clock-recovery device for clock extraction and the other is input into an intensity modulator (IM) whose input electrical data are synchronized by the extracted clock. The intensity-modulated signal is encoded and multiplexed with the encoded signals from other ONUs for the transmission to the OLT, where the upstream signal is split into N branches for decoding and detection.

3. All-optical self-clocked time gate

Optical time gates, widely used for wavelength conversion, optical signal regeneration, and demultiplexing, are essential devices in the optical communication networks [17

17. K. E. Stubkjaer, “Semiconductor optical amplifier-based all-optical gates for high-speed optical processing,” IEEE J. Sel. Top. Quantum Electron. 6(6), 1428–1435 (2000). [CrossRef]

]. Besides, time gates are also widely used in the optical code based technologies for signal extraction and multiple-access interference (MAI) suppression [18

18. V. J. Hernandez, W. Cong, J. Hu, C. Yang, N. K. Fontaine, R. P. Scott, Z. Ding, B. H. Kolner, J. P. Heritage, and S. J. B. Yoo, “A 320-Gb/s capacity (32-user×10 Gb/s) SPECTS O-CDMA network testbed with enhanced spectral efficiency through forward error correction,” J. Lightwave Technol. 25(1), 79–86 (2007). [CrossRef]

]. However, in a time gate, a synchronous clock signal is needed to extract a target signal from a data stream, which increases the complexity of systems and obliges systems to abandon the advantage of asynchronous transmission. To avoid using additional clock signal, self-clocked time gates have been proposed, where a clock signal can be obtained and used to extract a target signal from an original data stream [19

19. K. L. Deng, I. Glesk, K. I. Kang, and P. R. Prucnal, “Unbalanced TOAD for optical data and clock separation in self-clocked transparent OTDM networks,” IEEE Photon. Technol. Lett. 9(6), 830–832 (1997). [CrossRef]

, 20

20. N. Wada, H. Sotobayashi, and K. Kitayama, “Error-free 100km transmission at 10Gbit/s in optical code division multiplexing system using BPSK picosecond-pulse code sequence with novel time-gating detection,” Electron. Lett. 35(10), 833–834 (1999). [CrossRef]

].

In the first stage, an input signal is separated into two branches. In the upper branch, a supercontinuum (SC) based thresholder, which consists of a dispersion flattened fiber (DFF) and a bandpass filter (BPF), is used to generate a clock signal. In the DFF, only high-intensity pulses can generate SC, while low-intensity noises cannot generate SC. The following filter centered at another wavelength only allows the generated SC pass through. As a result, a train of high-intensity pulses with the same repetition rate of the data, i.e. a clock signal, is obtained. The SC based thresholder is widely used for MAI suppression in the OOK-OCDMA system [21

21. X. Wang, T. Hamanaka, N. Wada, and K. Kitayama, “Dispersion-flattened-fiber based optical thresholder for multiple-access-interference suppression in OCDMA system,” Opt. Express 13(14), 5499–5505 (2005). [CrossRef] [PubMed]

], but it is not suitable for DPSK systems, because the phase information cannot be preserved during the SC generation [22

22. R. Elschner, C.-A. Bunge, and K. Petermann, “System impact of cascaded all-optical wavelength conversion of D(Q)PSK signals in transparent optical networks,” J. Netw. 5, 219–224 (2010).

]. Thus, this technique is used for the extraction of clock signal instead of the reshaping of DPSK signals. The signal in the lower branch is adjusted by a tunable optical delay line (TODL) to ensure that the pulses are temporally overlapped with the pulses in the clock signal after a 3-dB coupler.

In the second stage, the coupled signals are injected into a nonlinear element (NLE) for four-wave mixing (FWM), which is a time gating process. In the FWM process, a phase-conjugate replica of the target signal is generated. A following filter is to filter out the generated replica.

The characteristics of the self-clocked time gate are experimentally investigated. In the experiment, a 10 GHz 1.5 ps (FWHM) Gaussian shaped pulse train is used as an input, whose center wavelength is at 1550 nm. The input operating power (at point α) is 14 mW, which means that the required peak power is 0.86 W. A span of 2 km DFF is used for supercontinuum generation and a 2 nm BPF centered at 1545 nm is to filter out the clock signal. In the two branches, two attenuators (ATT) and two polarization controllers (PC) are placed before coupling to optimize the FWM condition. In the second stage, a semiconductor optical amplifier (SOA) or a span of 100 m highly nonlinear fiber (HNLF) is used as an NLE.

The transfer function is illustrated in Fig. 3
Fig. 3 Operation principle of the self-clocked time gate.
. The input average power (Pα) and output average power (Pβ) are measured at the points α and β in Fig. 2. When input power is low, there is no output if the HNLF is used, while there are some very low outputs if the SOA is used, resulted from amplified spontaneous emission (ASE). When high power is input, high outputs can be obtained for both cases and the output power in the case of SOA is three times as that in the case of HNLF. Thus, the time gate can be applied to remove low-intensity noises, such as MAI. Insertion loss (10log(Pβ/Pα)) of the time gate using the SOA and the HNLF are about –16 dB and –21 dB at the operating points. Besides, the time gate using the HNLF is more polarization-sensitive. Therefore, the time gate using the SOA is used in the further experiments.

4. Experimental demonstration and results

The experimental demonstration is only to show the feasibility of the proposed OCDMA-PON. It has potential to further improve the system performance by applying a thresholder or a time gate to remove MAIs in the uplink. Besides that, like some hybrid systems for next-generation PON stage 2 (NG-PON2) such as time/wavelength-division multiplexing (TWDM) systems [5

5. P. J. Urban, B. Huiszoon, R. Roy, M. M. de Laat, F. M. Huijskens, E. J. Klein, G. D. Khoe, A. M. J. Koonen, and H. de Waardt, “High-bit-rate dynamically reconfigurable WDM-TDM access network,” J. Opt. Commun. Netw. 1(2), A143–A159 (2009). [CrossRef]

, 23

23. Y. Ma, Y. Qian, G. Peng, X. Zhou, X. Wang, J. Yu, Y. Luo, X. Yan, and F. Effenberger, “Demonstration of a 40Gb/s time and wavelength division multiplexed passive optical network prototype system,” in Optical Fiber Communication Conference (OFC), Los Angeles, California, paper PDP5D (2012).

], large scalability of the network can be achieved by introducing WDM techniques into the OCDMA-PON [1

1. K. Kitayama, X. Wang, and N. Wada, “OCDMA over WDM PON—solution path to gigabit-symmetric FTTH,” J. Lightwave Technol. 24(4), 1654–1662 (2006). [CrossRef]

].

5. Discussions

5.1 Performance improvement by employing all-optical self-clocked time gate

The all-optical self-clocked time gate is proposed and used in the OCDMA system for the first time. To acquire the potential properties of the time gate, the influence over the system improvement resulted from the time gate is experimentally investigated.

The performance analysis is carried out experimentally in the worst and the best situations which are defined as the most and the least MAIs overlapping with the target signal in the detection window. Figure 9
Fig. 9 Experimental setup of multi-user DPSKOCDMA system.
illustrates the measurement setup. A train of phase-modulated pulses are split into two branches and encoded by two encoders. In the measurement, not only 31-chip SSFBG en/decoders but also 63-chip 640 Gchip/s SSFBG en/decoders are tested. In the lower branch, the encoded pulse train is input into an MAI generator, which is to generate up to four MAIs by temporal pattern misalignment and power balance. Then, all encoded signals are multiplexed and transmitted to the receiving side. In the receiving side, the encoded signals are decoded and fed into the time gate. After the time gate, the signals are detected by a DPSK receiver, which consists of a one-bit delay interferometer and a balanced photodetector. In the experiment, the worst and the best situations are realized by adjusting the temporal alignment of each MAI user. Figure 10
Fig. 10 Experimental measurement of system improvement by using the time gate.
shows the power penalties between the situations with and without the use of the time gate. This comparison is conducted under the conditions when BER is 10−5 while the number of MAIs varies. The negative power penalty means the improvement of the performance while the positive values stands for the degradation. The worst and the best situations give upper and lower boundaries of the performance. The time gate cannot help the system to improve the performance when few MAIs overlap with the target signal, because in these situations the ASE noise from the SOA in the time gate dominates the degradation rather than the MAIs. When the number of MAIs increases, the time gate has more contributions to performance improvement, due to the efficient elimination of MAIs, which benefits multi-user systems.

5.2 Consideration of the power budget of the duplex transmission

7. Conclusion

Acknowledgment

The authors would like to thank Dr. J. M. Delgado Mendinueta for a fruitful discussion and Mr. H. Sumimoto of NICT for his technical support. Bo appreciates the Internship Research Fellowship awarded by NICT.

References and links

1.

K. Kitayama, X. Wang, and N. Wada, “OCDMA over WDM PON—solution path to gigabit-symmetric FTTH,” J. Lightwave Technol. 24(4), 1654–1662 (2006). [CrossRef]

2.

Z. A. El-Sahn, B. J. Shastri, Z. Ming, N. Kheder, D. V. Plant, and L. A. Rusch, “Experimental demonstration of a SAC-OCDMA PON with burst-mode reception: local versus centralized sources,” J. Lightwave Technol. 26(10), 1192–1203 (2008). [CrossRef]

3.

N. Kataoka, N. Wada, X. Wang, G. Cincotti, A. Sakamoto, Y. Terada, T. Miyazaki, and K. Kitayama, “Field trial of duplex, 10 Gbps x 8-user DPSK-OCDMA system using a single 16x16 multi-port encoder/decoder and 16-level phase-shifted SSFBG encoder/decoders,” J. Lightwave Technol. 27(3), 299–305 (2009). [CrossRef]

4.

J. Liu, D. Zeng, C. Guo, L. Xu, and S. He, “OCDMA PON supporting ONU inter-networking based on gain-switched Fabry-Pérot lasers with external dual-wavelength injection,” Opt. Express 18(22), 22982–22987 (2010). [CrossRef] [PubMed]

5.

P. J. Urban, B. Huiszoon, R. Roy, M. M. de Laat, F. M. Huijskens, E. J. Klein, G. D. Khoe, A. M. J. Koonen, and H. de Waardt, “High-bit-rate dynamically reconfigurable WDM-TDM access network,” J. Opt. Commun. Netw. 1(2), A143–A159 (2009). [CrossRef]

6.

G. Cincotti, N. Kataoka, N. Wada, X. Wang, T. Miyazaki, and K. Kitayama, “Demonstration of asynchronous, 10Gbps OCDMA PON system with colorless and sourceless ONUs,” in 35th European Conference and Exhibition on Optical Communication (ECOC 2009), Vienna, Austria, paper 6.5.7 (2009).

7.

W. Hung, C. K. Chan, L. K. Chen, and F. Tong, “An optical network unit for WDM access networks with downstream DPSK and upstream remodulated OOK data using injection-locked FP laser,” IEEE Photon. Technol. Lett. 15(10), 1476–1478 (2003). [CrossRef]

8.

C. W. Chow, “Wavelength remodulation using DPSK down-and-upstream with high extinction ratio for 10-Gb/s DWDM-passive optical networks,” IEEE Photon. Technol. Lett. 20(1), 12–14 (2008). [CrossRef]

9.

J. Yu, M. F. Huang, D. Qian, L. Chen, and G. K. Chang, “Centralized lightwave WDM-PON employing 16-QAM intensity modulated OFDM downstream and OOK modulated upstream signals,” IEEE Photon. Technol. Lett. 20(18), 1545–1547 (2008). [CrossRef]

10.

B. Dai, S. Shimizu, X. Wang, and N. Wada, “Full-asynchronous gigabit-symmetric OCDMA-PON with source-free ONUs based on DPSK downstream and remodulated OOK upstream links,” in 38th European Conference and Exhibition on Optical Communication (ECOC 2012), Amsterdam, the Netherlands, paper Mo.1.B.5 (2012).

11.

P. C. Teh, P. Petropoulos, M. Ibsen, and D. J. Richardson, “A comparative study of the performance of seven and 63-Chip optical code-division multiple-access encoders and decoders based on superstructured fiber Bragg gratings,” J. Lightwave Technol. 19(9), 1352–1365 (2001). [CrossRef]

12.

B. Dai, Z. Gao, X. Wang, N. Kataoka, and N. Wada, “Performance comparison of 0/π- and ± π/2-phase-shifted superstructured Fiber Bragg grating en/decoder,” Opt. Express 19(13), 12248–12260 (2011). [CrossRef] [PubMed]

13.

G. Cincotti, N. Wada, and K. Kitayama, “Characterization of a full encoder/decoder in the AWG configuration for code-based photonic routers — part I: modeling and design,” J. Lightwave Technol. 24(1), 103–112 (2006). [CrossRef]

14.

A. Agarwal, P. Toliver, R. Menendez, S. Etemad, J. Jackel, J. Young, T. Banwell, B. E. Little, S. T. Chu, W. Chen, W. Chen, J. Hryniewicz, F. Johnson, D. Gill, O. King, R. Davidson, K. Donovan, and P. J. Delfyett, “Fully programmable ring-resonator-based integrated photonic circuit for phase coherent applications,” J. Lightwave Technol. 24(1), 77–87 (2006). [CrossRef]

15.

X. Wang and Z. Gao, “Novel reconfigurable 2-dimensional coherent optical en/decoder based on coupled micro-ring reflector,” IEEE Photon. Technol. Lett. 23(9), 591–593 (2011). [CrossRef]

16.

I. Widjaja, “Performance analysis of burst admission-control protocols,” IEE Proc. Commun. 142(1), 7–14 (1995). [CrossRef]

17.

K. E. Stubkjaer, “Semiconductor optical amplifier-based all-optical gates for high-speed optical processing,” IEEE J. Sel. Top. Quantum Electron. 6(6), 1428–1435 (2000). [CrossRef]

18.

V. J. Hernandez, W. Cong, J. Hu, C. Yang, N. K. Fontaine, R. P. Scott, Z. Ding, B. H. Kolner, J. P. Heritage, and S. J. B. Yoo, “A 320-Gb/s capacity (32-user×10 Gb/s) SPECTS O-CDMA network testbed with enhanced spectral efficiency through forward error correction,” J. Lightwave Technol. 25(1), 79–86 (2007). [CrossRef]

19.

K. L. Deng, I. Glesk, K. I. Kang, and P. R. Prucnal, “Unbalanced TOAD for optical data and clock separation in self-clocked transparent OTDM networks,” IEEE Photon. Technol. Lett. 9(6), 830–832 (1997). [CrossRef]

20.

N. Wada, H. Sotobayashi, and K. Kitayama, “Error-free 100km transmission at 10Gbit/s in optical code division multiplexing system using BPSK picosecond-pulse code sequence with novel time-gating detection,” Electron. Lett. 35(10), 833–834 (1999). [CrossRef]

21.

X. Wang, T. Hamanaka, N. Wada, and K. Kitayama, “Dispersion-flattened-fiber based optical thresholder for multiple-access-interference suppression in OCDMA system,” Opt. Express 13(14), 5499–5505 (2005). [CrossRef] [PubMed]

22.

R. Elschner, C.-A. Bunge, and K. Petermann, “System impact of cascaded all-optical wavelength conversion of D(Q)PSK signals in transparent optical networks,” J. Netw. 5, 219–224 (2010).

23.

Y. Ma, Y. Qian, G. Peng, X. Zhou, X. Wang, J. Yu, Y. Luo, X. Yan, and F. Effenberger, “Demonstration of a 40Gb/s time and wavelength division multiplexed passive optical network prototype system,” in Optical Fiber Communication Conference (OFC), Los Angeles, California, paper PDP5D (2012).

24.

X. Wang, K. Matsushima, A. Nishiki, N. Wada, and K. Kitayama, “High reflectivity superstructured FBG for coherent optical code generation and recognition,” Opt. Express 12(22), 5457–5468 (2004). [CrossRef] [PubMed]

OCIS Codes
(060.0060) Fiber optics and optical communications : Fiber optics and optical communications
(060.4080) Fiber optics and optical communications : Modulation
(060.4250) Fiber optics and optical communications : Networks
(070.4340) Fourier optics and signal processing : Nonlinear optical signal processing

ToC Category:
Access Networks and LAN

History
Original Manuscript: October 1, 2012
Revised Manuscript: November 2, 2012
Manuscript Accepted: November 7, 2012
Published: November 28, 2012

Virtual Issues
European Conference on Optical Communication 2012 (2012) Optics Express

Citation
Bo Dai, Satoshi Shimizu, Xu Wang, and Naoya Wada, "Full-asynchronous gigabit-symmetric DPSK downstream and OOK upstream OCDMA-PON with source-free ONUs employing all-optical self-clocked time gate," Opt. Express 20, B21-B31 (2012)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-20-26-B21


Sort:  Author  |  Year  |  Journal  |  Reset  

References

  1. K. Kitayama, X. Wang, and N. Wada, “OCDMA over WDM PON—solution path to gigabit-symmetric FTTH,” J. Lightwave Technol.24(4), 1654–1662 (2006). [CrossRef]
  2. Z. A. El-Sahn, B. J. Shastri, Z. Ming, N. Kheder, D. V. Plant, and L. A. Rusch, “Experimental demonstration of a SAC-OCDMA PON with burst-mode reception: local versus centralized sources,” J. Lightwave Technol.26(10), 1192–1203 (2008). [CrossRef]
  3. N. Kataoka, N. Wada, X. Wang, G. Cincotti, A. Sakamoto, Y. Terada, T. Miyazaki, and K. Kitayama, “Field trial of duplex, 10 Gbps x 8-user DPSK-OCDMA system using a single 16x16 multi-port encoder/decoder and 16-level phase-shifted SSFBG encoder/decoders,” J. Lightwave Technol.27(3), 299–305 (2009). [CrossRef]
  4. J. Liu, D. Zeng, C. Guo, L. Xu, and S. He, “OCDMA PON supporting ONU inter-networking based on gain-switched Fabry-Pérot lasers with external dual-wavelength injection,” Opt. Express18(22), 22982–22987 (2010). [CrossRef] [PubMed]
  5. P. J. Urban, B. Huiszoon, R. Roy, M. M. de Laat, F. M. Huijskens, E. J. Klein, G. D. Khoe, A. M. J. Koonen, and H. de Waardt, “High-bit-rate dynamically reconfigurable WDM-TDM access network,” J. Opt. Commun. Netw.1(2), A143–A159 (2009). [CrossRef]
  6. G. Cincotti, N. Kataoka, N. Wada, X. Wang, T. Miyazaki, and K. Kitayama, “Demonstration of asynchronous, 10Gbps OCDMA PON system with colorless and sourceless ONUs,” in 35th European Conference and Exhibition on Optical Communication (ECOC 2009), Vienna, Austria, paper 6.5.7 (2009).
  7. W. Hung, C. K. Chan, L. K. Chen, and F. Tong, “An optical network unit for WDM access networks with downstream DPSK and upstream remodulated OOK data using injection-locked FP laser,” IEEE Photon. Technol. Lett.15(10), 1476–1478 (2003). [CrossRef]
  8. C. W. Chow, “Wavelength remodulation using DPSK down-and-upstream with high extinction ratio for 10-Gb/s DWDM-passive optical networks,” IEEE Photon. Technol. Lett.20(1), 12–14 (2008). [CrossRef]
  9. J. Yu, M. F. Huang, D. Qian, L. Chen, and G. K. Chang, “Centralized lightwave WDM-PON employing 16-QAM intensity modulated OFDM downstream and OOK modulated upstream signals,” IEEE Photon. Technol. Lett.20(18), 1545–1547 (2008). [CrossRef]
  10. B. Dai, S. Shimizu, X. Wang, and N. Wada, “Full-asynchronous gigabit-symmetric OCDMA-PON with source-free ONUs based on DPSK downstream and remodulated OOK upstream links,” in 38th European Conference and Exhibition on Optical Communication (ECOC 2012), Amsterdam, the Netherlands, paper Mo.1.B.5 (2012).
  11. P. C. Teh, P. Petropoulos, M. Ibsen, and D. J. Richardson, “A comparative study of the performance of seven and 63-Chip optical code-division multiple-access encoders and decoders based on superstructured fiber Bragg gratings,” J. Lightwave Technol.19(9), 1352–1365 (2001). [CrossRef]
  12. B. Dai, Z. Gao, X. Wang, N. Kataoka, and N. Wada, “Performance comparison of 0/π- and ± π/2-phase-shifted superstructured Fiber Bragg grating en/decoder,” Opt. Express19(13), 12248–12260 (2011). [CrossRef] [PubMed]
  13. G. Cincotti, N. Wada, and K. Kitayama, “Characterization of a full encoder/decoder in the AWG configuration for code-based photonic routers — part I: modeling and design,” J. Lightwave Technol.24(1), 103–112 (2006). [CrossRef]
  14. A. Agarwal, P. Toliver, R. Menendez, S. Etemad, J. Jackel, J. Young, T. Banwell, B. E. Little, S. T. Chu, W. Chen, W. Chen, J. Hryniewicz, F. Johnson, D. Gill, O. King, R. Davidson, K. Donovan, and P. J. Delfyett, “Fully programmable ring-resonator-based integrated photonic circuit for phase coherent applications,” J. Lightwave Technol.24(1), 77–87 (2006). [CrossRef]
  15. X. Wang and Z. Gao, “Novel reconfigurable 2-dimensional coherent optical en/decoder based on coupled micro-ring reflector,” IEEE Photon. Technol. Lett.23(9), 591–593 (2011). [CrossRef]
  16. I. Widjaja, “Performance analysis of burst admission-control protocols,” IEE Proc. Commun.142(1), 7–14 (1995). [CrossRef]
  17. K. E. Stubkjaer, “Semiconductor optical amplifier-based all-optical gates for high-speed optical processing,” IEEE J. Sel. Top. Quantum Electron.6(6), 1428–1435 (2000). [CrossRef]
  18. V. J. Hernandez, W. Cong, J. Hu, C. Yang, N. K. Fontaine, R. P. Scott, Z. Ding, B. H. Kolner, J. P. Heritage, and S. J. B. Yoo, “A 320-Gb/s capacity (32-user×10 Gb/s) SPECTS O-CDMA network testbed with enhanced spectral efficiency through forward error correction,” J. Lightwave Technol.25(1), 79–86 (2007). [CrossRef]
  19. K. L. Deng, I. Glesk, K. I. Kang, and P. R. Prucnal, “Unbalanced TOAD for optical data and clock separation in self-clocked transparent OTDM networks,” IEEE Photon. Technol. Lett.9(6), 830–832 (1997). [CrossRef]
  20. N. Wada, H. Sotobayashi, and K. Kitayama, “Error-free 100km transmission at 10Gbit/s in optical code division multiplexing system using BPSK picosecond-pulse code sequence with novel time-gating detection,” Electron. Lett.35(10), 833–834 (1999). [CrossRef]
  21. X. Wang, T. Hamanaka, N. Wada, and K. Kitayama, “Dispersion-flattened-fiber based optical thresholder for multiple-access-interference suppression in OCDMA system,” Opt. Express13(14), 5499–5505 (2005). [CrossRef] [PubMed]
  22. R. Elschner, C.-A. Bunge, and K. Petermann, “System impact of cascaded all-optical wavelength conversion of D(Q)PSK signals in transparent optical networks,” J. Netw.5, 219–224 (2010).
  23. Y. Ma, Y. Qian, G. Peng, X. Zhou, X. Wang, J. Yu, Y. Luo, X. Yan, and F. Effenberger, “Demonstration of a 40Gb/s time and wavelength division multiplexed passive optical network prototype system,” in Optical Fiber Communication Conference (OFC), Los Angeles, California, paper PDP5D (2012).
  24. X. Wang, K. Matsushima, A. Nishiki, N. Wada, and K. Kitayama, “High reflectivity superstructured FBG for coherent optical code generation and recognition,” Opt. Express12(22), 5457–5468 (2004). [CrossRef] [PubMed]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.


« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited