• No results found

All-optical multi-wavelength conversion with negative power penalty by a commercial SOA-MZI for WDM wavelength multicast

N/A
N/A
Protected

Academic year: 2021

Share "All-optical multi-wavelength conversion with negative power penalty by a commercial SOA-MZI for WDM wavelength multicast"

Copied!
4
0
0

Bezig met laden.... (Bekijk nu de volledige tekst)

Hele tekst

(1)

All-optical multi-wavelength conversion with negative power

penalty by a commercial SOA-MZI for WDM wavelength

multicast

Citation for published version (APA):

Yan, N., Jung, H. D., Tafur Monroy, I., Waardt, de, H., & Koonen, A. M. J. (2007). All-optical multi-wavelength conversion with negative power penalty by a commercial SOA-MZI for WDM wavelength multicast. In

Proceedings of the Conference on Optical Fiber Communication and the National Fiber Optic Engineers Conference, (OFC / NFOC 2007) 25-29 March 2007, Anaheim, California, USA [JWA36] Institute of Electrical and Electronics Engineers. https://doi.org/10.1109/OFC.2007.4348422

DOI:

10.1109/OFC.2007.4348422 Document status and date: Published: 01/01/2007

Document Version:

Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers)

Please check the document version of this publication:

• A submitted manuscript is the version of the article upon submission and before peer-review. There can be important differences between the submitted version and the official published version of record. People interested in the research are advised to contact the author for the final version of the publication, or visit the DOI to the publisher's website.

• The final author version and the galley proof are versions of the publication after peer review.

• The final published version features the final layout of the paper including the volume, issue and page numbers.

Link to publication

General rights

Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain

• You may freely distribute the URL identifying the publication in the public portal.

If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license above, please follow below link for the End User Agreement:

www.tue.nl/taverne Take down policy

If you believe that this document breaches copyright please contact us at: openaccess@tue.nl

providing details and we will investigate your claim.

(2)

All-Optical Multi-Wavelength Conversion with Negative

Power Penalty by a Commercial SOA-MZI for WDM

Wavelength Multicast

Ni Yan, Hyun-Do Jung, Idelfonso Tafur Monroy, Huug de Waardt, Ton Koonen

Potentiaal, Eindhoven University of Technology, Eindhoven, Netherlands n.yan@tue.nl

Abstract: WDM wavelength multicast is demonstrated by all-optical multi-wavelength

conversion at 10 Gb/s using a commercial SOA-MZI. We report for the first time simultaneous one-to-four conversion with negative power penalty of 1.84 dB.

2006 Optical Society of America

OCIS codes: (060.4510) Optical communications; (190.2620) Frequency conversion

1. Introduction

Wavelength division multiplexing (WDM) multicast is a function implemented today in the electronic layer by multiple optic-electronic-optic (OEO) transponders or by optical power splitters [1]. The former requires OEO conversion and electronics for each wavelength multicast channel, adding the operational cost and reducing the transparency. The latter necessitates a large amount of power consuming optical amplifiers to compensate the power loss in the splitting process. Therefore, all-optical multicast by multi-wavelength conversion (MWC) is attractive for making multiple copies directly in the optical domain, an innovative step towards the next-generation intelligent all-optical wavelength-routed or packet/burst switched network.

Various MWC technologies have been demonstrated during recent years. To name a few, four-wave mixing (FWM) [2-4], cross-phase modulation (XPM) [5-7], cross absorption modulation (XAM) [8-10] and cross-gain modulation (XGM) [11] have proven promising results for WDM wavelength-routed multicast. However, FWM is limited by its low conversion efficiency and wavelength inflexibility [2-4]. XAM suffers from the large insertion loss of the electroabsorption modulator utilized and only MWC of RZ signals has been demonstrated [8-10]. XGM by double-stage semiconductor optical amplifiers (SOAs) requires high input signal optical power because of the splitting process to both SOAs [11].

Compared to the other approaches, a multi-wavelength converter by XPM in a SOA-based Mach-Zehnder interferometer (SOA-MZI) stands distinguished advantages [5-7]: it supports both RZ and NRZ data format; it is compact and even several SOA-MZIs can be integrated on a single motherboard; it is power economical and provides satisfactory conversion efficiency; it is a switching element that is widely used and commercially available that allows massive production; its principle and schematic are also simple and straightforward, requiring no more complexity than any of the other methods; it supports high data rates such as 40 Gb/s as the SOAs allow and even higher bit rates in a push-pull operation [5]. MWC can be easily achieved providing a data signal and continuous waves (CWs) on the desired multicast channels to the device.

In this paper, we demonstrate for the first time to our knowledge, simultaneous MWC by a SOA-MZI of 10 Gb/s NRZ signals with negative power penalty of 1.84 dB and channel variation of 0.12 dB at bit-error rate (BER) of 10-9, without any additional assist light. Our results proved the promising performance of a SOA-MZI for optical wavelength multicast applications and improved receiver sensitivity. The number of channels in our setup was only limited by our available laser sources. The maximum channel number is decided by the SOA gain spectrum. With a SOA-MZI of higher operation speed our apparatus can easily accommodate higher bit-rate operation of 40 Gb/s or more.

2. Experimental setup and operation principle

Fig. 1 shows the experimental setup for simultaneous MWC from a single channel to four different multicast channels. The commercially available SOA-MZI wavelength converter is manufactured by HHI for 10 Gb/s operation. We used ITU 100 GHz grid wavelengths. The data signal on 1541.35 nm was modulated by a 10 Gb/s NRZ pseudorandom bit sequence with the pattern length of 231-1 as the input to SOA-MZI arm P1. Four CWs at wavelengths 1544.53 nm, 1545.32 nm, 1546.12 nm and 1546.92 nm were combined by a four-to-one coupler and injected in the co-propagating direction into port P2. The average input power to P1 is kept at about -1.13 dBm and the total input power at P2 is 0 dBm with each CW channel attenuated to - 6 dBm. One erbium-doped fiber amplifier (EDFA) was used to compensate the insertion loss of the intensity modulator (IM) but no amplifiers for the CW channels were required. Optical multicast signals could be obtained from both arms P4 and P5, but only

a1662_1.pdf

JWA36.pdf

©OSA 1-55752-830-6

(3)

wavelength converted channels at P4 were selected for the BER test. A second EDFA was deployed as a preamplifier. Both EDFAs were configured to the automatic power control (APC) mode with a fixed output power specified. The SOA-MZI was kept at 20°C while SOA1 and SOA2 were biased at 242.96 mA and 310.95 mA.

Fig. 1. Experimental setup of 10 Gb/s one-to-four multi-wavelength conversion by a SOA-MZI

The SOA-MZI was operated in the standard configuration where the data signal was sent to only one of the two arms to induce a phase shift on the CWs via XPM. The MZI translated the phase modulation into an amplitude modulation. Because the phase change is only weakly dependent on wavelength, single data signals can be simultaneously transferred onto multiple CW channels.

3. Results and discussion

Fig. 2 (a) presents the output spectrum of the MWC at P4. Data were converted onto all the four channels. The output optical signal-to-noise ratio (OSNR) for the four channels lay inside the range of 38~43 dB. The 100 GHz spacing resulted several FWM satellite signals from the SOA nonlinear effect that were about 20 dB weaker or more than the desired converted channels. However, these satellite signals did not affect the BER performance of all the simultaneously converted channels as shown in Fig. 2 (b), with respect to the back-to-back signals where the SOA-MZI was bypassed. We used a 0.3 nm narrow band tunable optical filter (OF) for individual channel selection. All the channels were converted with an improved receiver sensitivity of 1.84 dB or more, where the sensitivity variation among the converted channels was measured to be only 0.12 dB. Both back-to-back signal and one converted channel eye diagrams are shown as insets.

(a) (b)

Fig. 2. (a) Output spectrum at SOA-MZI port P4, (b) BER results for all converted channels compared to back-to-back signal

In Fig. 3 we plotted the output eye signal-to-noise ratio (S/N) and extinction ratio (ER) of the four converted channels with their eye diagram snapshots inserted as insets. All the channels exhibited clear and widely open eyes with an average eye S/N of 8.36 and an average ER of 10.63 dB. The converted eyes indicate a slightly lowered eye crossing point which according to the BER measurements did not have any negative influence on the system

a1662_1.pdf

JWA36.pdf

©OSA 1-55752-830-6

(4)

performance, as all the channels including the back-to-back signal were measured with the same default threshold level.

Fig. 3. Output eye signal to noise ratio (S/N)-left axis and extinction ratio (ER)-right axis of the four converted channels with eye diagram snapshots shown as insets

4. Conclusions

We have experimentally demonstrated all-optical simultaneous multicast by MWC of 10 Gb/s NRZ data to four different 100 GHz spacing wavelength channels, deploying a single SOA-MZI without any additional assist light apart from the signal and probe CWs. The BER performance of our multi-wavelength converter exhibited error-free operation and an improved receiver sensitivity of at least 1.84 dB with a channel sensitivity variation of merely 0.12 dB. Our results confirmed the promising application of MWC by XPM in a SOA-MZI for transparent all-optical WDM wavelength multicast.

The number of MWC copies we demonstrated was only restricted by the available laser sources. Our apparatus can accommodate many more channels as long as they are located inside the SOA gain bandwidth. The setup can also be applied to MWC of RZ signals [5,6]. With a faster SOA dynamics or a push-pull scheme [5] the application can be used for MWC at higher bit rate such as 40 Gb/s.

5. References

[1] G.N. Rouskas, “Optical layer multicast: rationale, building blocks, and challenges,” IEEE Network 17, 60-65 (2003). [2] S.J.B. Yoo, “Wavelength conversion technologies for WDM network applications,” JLT 14, 955-966 (1996).

[3] G. Contestabile et al, “Multiple wavelength conversion for WDM multicasting by FWM in an SOA”, PTL 16, no. 7, 1775-1777 (2004). [4] N. Yan et al, “Optical multicasting performance evaluation using multi-wavelength conversion by four-wave mixing in DSF at 10/20/40

Gb/s,” in Proc. IEEE Photonics in Switching, (to be published, Heraklion, Greece, 16-18 Oct. 2006).

[5] D. Reading-Picopoulos et al, “10Gb/s and 40Gb/s WDM multi-casting using a hybrid integrated Mach-Zehnder interferometer”, OFC 2006, OFP2 (2006).

[6] H.S. Chung et al, “All-optical multi-wavelength conversion of 10 Gbit/s NRZ/RZ signals based on SOA-MZI for WDM multicasting”, Elect. Lett. 41, no. 7, 432-433 (2005).

[7] J.L. Pleumeekers et al, “All-optical wavelength conversion and broadcasting to eight separate channels by a single semiconductor optical amplifier delay interferometer,” OFC 2002, 596-597 (2002).

[8] L. Xu et al, “7 × 40 Gb/s base-rate RZ all-optical broadcasting utilizing an electroabsorption modulator,” OSA Opt. Express 12, no. 3, 416-420 (2004).

[9] L. Xu et al, “8 × 40 Gb/s RZ all-optical broadcasting utilizing an electroabsorption modulator,” OFC 2004, MF71 (2004).

[10] K.K. Chow et al, “All-optical signal regeneration with wavelength multicasting at 6×10 Gb/s using a single electroabsorption modulator,” Opt. Express 12, no. 13, 3050-3054 (2004).

[11] G. Contestabile et al, “Double-stage cross-gain modulation in SOAs: an effective technique for WDM multicasting,” PTL 18, no. 1, 181-183 (2006). a1662_1.pdf

JWA36.pdf

©OSA 1-55752-830-6

Referenties

GERELATEERDE DOCUMENTEN

Publisher’s PDF, also known as Version of Record (includes final page, issue and volume numbers) Please check the document version of this publication:.. • A submitted manuscript is

4. Machinefabrikanten als adviseurs en leveranciers van materiaal Op het moment dat de vennootschappen-in-oprichting uitzicht hadden op voldoende startkapitaal, kwamen de

Een sproeicycloon biedt perspectief voor gas-vloeistofprocessen waarbij hoge parti~le overdrachtscoëfficiënten aan de gaszijde van het contactopper- vlak, korte ~ contacttijden,

These additional data emphasize that –in addition to a general biological variation among tissues in ribosomal protein mRNA expression- evolutionary conserved more profound

Background: We investigated the prevalence of and factors associated with post-traumatic stress disorder (PTSD) and common mental disorders (CMDs), which include depression and

The clinical dilemma was as follows: was this (i) a systemic NHL with extranodal involvement of the left breast; (ii) an overlooked primary breast lymphoma (PBL); or (iii)

The major primary obstetric events leading to perinatal deaths in the western Cape are antepartum haemo_rrhage, spontaneous preterm labour, unexplained intra-uterine death,