Optical label switching is a technique for more effective use of the processing speed of electronic IP routers. In this technique IP packets are accompanied by small optical labels, which the node uses for routing and forwarding decisions. In each node only the label is recovered, processed electronically and a new label is reinserted, while the payload remains in the optical domain. One method for labelling IP packets is orthogonal FSK/IM modulation, where the payload is ‘Intensity Modulated’ (IM) and the label is ‘Frequency Modulated’ (FSK). Transmission through optical filters, i.e. multiplexers and passive AWG routers can cause signal degradation. When a combined FSK/IM signal is not well filtered, the two FSK ones will induce intensity fluctuations, which can result in FSK to IM conversion. In this paper, we show simulation and experimental results of how the combined FSK/IM scheme performs with respect to signal degradation due to laser nominal wavelength detuning and optical filter misalignments. Further we show analytical results on the relation between required optical filter bandwidth and frequency deviation.
[1]
I. Roudas,et al.
Cascadability of passband-flattened arrayed waveguide-grating filters in WDM optical networks
,
1999,
IEEE Photonics Technology Letters.
[2]
S. L. Danielsen,et al.
All-optical wavelength conversion by semiconductor optical amplifiers
,
1996
.
[3]
C. Caspar,et al.
Cascadability of arrayed-waveguide grating (de)multiplexers in transparent optical networks
,
1997,
Proceedings of Optical Fiber Communication Conference (.
[4]
Chunming Qiao,et al.
Labeled optical burst switching for IP-over-WDM integration
,
2000,
IEEE Commun. Mag..
[5]
G. Morthier,et al.
Optical packet routing in IP-over-WDM networks deploying two-level optical labeling
,
2001,
Proceedings 27th European Conference on Optical Communication (Cat. No.01TH8551).
[6]
Yonglin Yu,et al.
High bit-rate combined FSK/IM modulated optical signal generation by using GCSR tunable laser sources.
,
2003,
Optics express.