Details

Autor(en) / Beteiligte

• Wang, Cheng
• Sun, Yiwei
• Wu, Guiling
• Chen, Jianping

Titel

Effects of the Nonlinearity Caused by the 'MZM-WDM' Structure in Time-Wavelength Interleaved Photonic Analog-to-Digital Converters

Ist Teil von

• Journal of lightwave technology, 2021-12, Vol.39 (23), p.7447-7454

Ort / Verlag

New York: IEEE

Erscheinungsjahr

2021

Link zum Volltext

• IEEE_Xplore

Quelle

IEEE Xplore

Beschreibungen/Notizen

• The effects of the nonlinearity caused by the structure of 'Mach-Zehnder modulator (MZM) - wavelength division demultiplexer (WDM)' in Time-Wavelength Interleaved Photonic Analog-to-Digital Converters is studied for the first time. Even if the MZM is biased at quadrature, the narrow passband width of the WDM after modulation may result in the presentation of even harmonics in the spectrum of the sampling results. As the radio frequency (RF) of the signal being sampled increases and the passband width of the WDM decreases, the magnitudes of the even harmonics increase. As a result, the spur-free dynamic range (SFDR) would be determined by the magnitudes of the signal and the 2<inline-formula><tex-math notation="LaTeX">{^{\rm {nd}}}</tex-math></inline-formula> harmonic instead of the 3<inline-formula><tex-math notation="LaTeX">{^{\rm {rd}}}</tex-math></inline-formula> harmonic. When the passband width of the WDM is less than 100 GHz, the variation of the SFDR can be as much as 6 dB over 0<inline-formula><tex-math notation="LaTeX">\sim</tex-math></inline-formula>25 GHz-frequency range of the signal being sampled. Theoretical analysis is verified by the simulation and experimental results. When the passband width of the WDM is greater than 150 GHz, the SFDR over 0<inline-formula><tex-math notation="LaTeX">\sim</tex-math></inline-formula>25 GHz-RF range is always dominated by the 3<inline-formula><tex-math notation="LaTeX">{^{\rm {rd}}}</tex-math></inline-formula> harmonic. When the passband width is 50 GHz, the SFDR is dominated by the 2<inline-formula><tex-math notation="LaTeX">{^{\rm {nd}}}</tex-math></inline-formula> harmonic for RF frequencies above 10 GHz, and can be as much as 20 dB higher than the 3<inline-formula><tex-math notation="LaTeX">{^{\rm {rd}}}</tex-math></inline-formula> harmonic term at 25 GHz-RF frequency. The requirement for the passband width of the WDM can be specified according to the frequency range of the signal being sampled to avoid the presentation of even harmonics and optimize the design of TWIPADCs.