Abstract
An optical single sideband modulator without generating both the -2nd and +2nd order sidebands is presented. It is based on parallel operation of two dual-drive Mach-Zehnder modulators (DDMZMs) where one is operated as a conventional single sideband (SSB) modulator and the other is operated as a single-drive Mach-Zehnder modulator (MZM) biased at the maximum transmission point. The 2nd order sidebands generated by the SSB modulator and the maximum-biased MZM can be cancelled by controlling the sideband amplitude and phase. Cancelling the 2nd order sidebands eliminates the second order harmonic component presented at the output of a long-reach fibre optic link. The new SSB modulator can be implemented using standard off-the-shelf components and has a wide bandwidth. Experimental results show > 20 dB 2nd order sidebands suppression for different modulation indexes and 22.6 dB reduction in the fibre optic link output second order harmonic component, compared to using a conventional SSB modulator formed by a DDMZM and a 90° hybrid coupler. Results also demonstrate the performance of the new SSB modulator is insensitive to the optical carrier frequency and the input RF signal frequency.
Original language | English |
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Article number | 17799888 |
Pages (from-to) | 1-10 |
Number of pages | 10 |
Journal | IEEE Photonics Journal |
Volume | 10 |
Issue number | 3 |
DOIs | |
Publication status | Published - Jun 2018 |