Optical Single Sideband Signal Generation Research Articles

Experimental demonstration of optical single sideband signal generation based on multi-frequency phase modulation in optical fibers

We theoretically analyzed and experimentally demonstrated the feasibility of optical single sideband (OSSB) signal generation based on multi-frequency phase modulation. The numerically calculated results show that OSSB signal can be efficiently generated with the proposed method. Optical carrier suppression ratio (OCSR), optical sideband suppression ratio (OSSR) and energy efficiency (EF) of the modulated optical signal increase with the quantity of harmonic waves in the modulation signal. In a principle verifying experiment, 6 frequency phase modulation was carried out with a narrow line-width fiber laser and a LiNbO3 electro-optic phase modulator. The fundamental frequency of the modulation signal was controlled to 30 MHz. OCSR of 18.9 dB, OSSR of 14.1 dB and EF of 78% were obtained, respectively. The experimental results agree well with the numerically calculated results. The proposed scheme provides an effective way to generate an OSSB signal for optical communication or optical sensing systems.

Photonics-Based Microwave Switching Using Optical Single Sideband Wavelength Conversion in a Semiconductor Optical Amplifier

Photonics-based microwave switching using optical single sideband (OSSB) wavelength conversion in a semiconductor optical amplifier (SOA) is proposed and demonstrated. By using the joint four-wave mixing and self-phase modulation effects in the SOA, the scheme can simultaneously realize the OSSB signal generation and photonic microwave switching, which can minimize the switching crosstalk, since the OSSB signal occupies the least optical bandwidth. This method is also simple as only a single SOA is required. Photonic switching of a 200-Mb/s 16-QAM signal centered at 20 GHz is performed. The signal after switching is an OSSB signal, which has a 22.65- or 17.85-dB sideband suppression ratio for switching based on wavelength down- or up-conversion, respectively. An investigation with the switched signals to combat the dispersion-induced power fading effect for radio over fiber application is also taken. Performance dependence of the optical pump and probe powers, the optical probe-pump power ratio, the modulation depth of the probe signal, and the SOA bias current are also investigated and analyzed.

Optical single sideband signal generation relying on a single‐drive Mach–Zehnder modulator for radio over fibre communications

Optical single sideband (OSSB) signals are conventionally generated using a dual-drive Mach–Zehnder modulator (MZM) or by using a single-drive MZM in conjunction with a fibre Bragg grating filter. In this study, the authors propose and mathematically characterise a novel radio over fibre downlink in which an OSSB signal is generated using a single-drive, rather than dual-drive, MZM without any additional filter. Additionally, their proposed scheme can achieve optical upconversion of the electronic signal. Furthermore, in addition to cost advantages, the proposed scheme's bit error ratio (BER) performance is better than the classical OSSB signal generation scheme.

Performance Comparison with Various Methods for Optical Single Sideband Signal Generation

Performance Comparison with Various Methods for Optical Single Sideband Signal Generation