The purpose of this part of IEC 61282, which is a Technical Report, is to provide a definition for in-band optical signal-to-noise ratio (OSNR) that is applicable to situations where the spectral noise power density is not independent of the optical frequency, as assumed in the OSNR definition of IEC 61280-2-9, but is significantly shaped across the optical bandwidth of the signal. Considering the development of multiple measurement methods for different use cases, as detailed below, it is desirable to establish a definition of in-band OSNR that is independent of the method used and, furthermore, is consistent with the OSNR definition of IEC 61280-2-9 in the case of frequency-independent noise power density.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 4<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 8<\/td>\n | 1 Scope 2 Normative references 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | 4 Background 4.1 General <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | 4.2 Higher spectral density of signals Figures Figure 1 \u2013 Optical power spectrum composed of a modulated signal and ASE noise <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 4.3 Spectral filtering in wavelength-routing elements Figure 2 \u2013 Optical power spectrum of 50-GHz spaced 40\u00a0Gbit\/s RZ-DQPSK signals with significant spectral overlap <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 4.4 Transmission of signals with multiple subcarriers Figure 3 \u2013 Optical power spectrum of 50-GHz spaced 10\u00a0Gbit\/s NRZ-OOK signals after spectral filtering in ROADMs Figure 4 \u2013 Optical power spectrum of a 400\u00a0Gbit\/s optical “superchannel” comprised of four very densely spaced 100\u00a0Gbit\/s PM-QPSK signals <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 5 In-band OSNR measurement with spectrally shaped noise 5.1 Measurement of in-band ASE noise <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 5.2 In-band OSNR definitions 5.2.1 Background 5.2.2 Spectrally integrated in-band OSNR <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 5.2.3 In-band OSNR from averaged noise power spectral density 5.2.4 In-band OSNR from maximal noise power spectral density <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 5.2.5 In-band OSNR for individual optical subcarriers 5.3 Spectral shaping of ASE noise 5.3.1 General 5.3.2 Case (a): ASE noise shaped outside of the signal spectrum <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 5.3.3 Case (b): ASE noise shaped within the signal spectrum Figure 5 \u2013 Power spectral density of a 10\u00a0Gbit\/s signal with ASE noise that has been shaped by a relatively broad optical filter <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 5.3.4 Case (c): ASE noise shaping in a ROADM network Figure 6 \u2013 Power spectral densities of a broadband 40 Gbit\/s signal and ASE noise which have been shaped by the same filter Figure 7 \u2013 Variation of the in-band OSNR values Rint, Ravg and Rmax versus filter bandwidth for the signal shown in Figure 6 <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | Figure\u00a08 \u2013 Optical power density spectra of signal and ASE noise after filtering in a ROADM network with intermediate amplification <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 6 Guidelines for using the definitions 6.1 General Figure 9 \u2013 Variation of the in-band OSNR values Rint, Ravg and Rmax versus number of filters for the signal shown in Figure\u00a08 <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 6.2 Wavelength integration range <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | Figure\u00a010 \u2013 Impact of integration range on Rint for 43 Gbit\/s RZ-DPSK signals in a ROADM network Figure 11 \u2013 Impact of instrument noise on s(\u03bd)\/\u03c1(\u03bd) for strongly filtered 10 Gbit\/s NRZ-OOK signals <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 6.3 Spectral resolution <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | Figure 12 \u2013 Dependence of in-band OSNR on spectral resolution for 43\u00a0Gbit\/s RZ-DQPSK signals <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | Figure 13 \u2013 Dependence of in-band OSNR on spectral resolution for 10 Gbit\/s NRZ-OOK signals <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 7 In-band OSNR penalties of filtered signals 7.1 Scope of simulations <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 7.2 Results for 43 Gbit\/s RZ-DQPSK Figure 14 \u2013 ROADM filter arrangements for OSNR penalty simulations <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | Figure 15 \u2013 In-band OSNR penalties for filtered 43\u00a0Gbit\/s RZ-DQPSK signals <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | Figure 16 \u2013 In-band OSNR penalties for filtered 128\u00a0Gbit\/s PM NRZ-QPSK signals <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | Figure 17 \u2013 In-band OSNR penalties for filtered 10\u00a0Gbit\/s NRZ-OOK signals <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 7.3 Results for 128 Gbit\/s PM NRZ-QPSK 7.4 Results for 10 Gbit\/s NRZ-OOK 7.5 Observations <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Fibre optic communication system design guides – In-band optical signal-to-noise ratio (OSNR)<\/b><\/p>\n |