Generation of triangular waveform radiofrequency signals based on photonic filtering using a broad-spectrum source
Keywords:Optical waveforms, photonic filtering, low coherence source, microwave photonics
This work proposes a photonic method to generate optical pulses with a triangular wave shape using a low coherence source. We modulate this source using a sinusoidal radio frequency signal as a local oscillator. We eliminate the second harmonic of the spectral components generated by the modulation process tuning a reject filter to get a triangular wave. We implement the filter using an interferometer with a delay line in one of their branches. To tune the filter, the only adjustment required is over the optical delay line. We developed our scheme in a simulation environment but based on the use of optical and optoelectronic elements with parameters of commercial devices, some of them available in our laboratory. We generate triangular waveform signals with pulse frequencies of 100, 150, 250, and 300 MHz as proof of concept. The proposed scheme has the advantage of being low cost and easy to use because it does not require bias control nor adjustment to Vpi voltage. Usually, other authors must vary these parameters to get the desired electrical signal. Still, we generate the triangular waveform by adjusting only the local oscillator frequency and the optical delay line. Therefore, because we use a broad-spectrum optical source and do not require a strictly controlled variable voltage, our system will be cheaper.
J. Yao, “Microwave photonics,” J. Light. Technol., vol. 27, no. 3, pp. 314–335, (2009), doi: 10.1109/MWSYM.2006.249900.
M. Du et al., “Photonic generation of frequency-doubled microwave waveforms based on cascaded Mach-Zehnder modulator,” Optik (Stuttg)., vol. 240, no. March, p. 166933, 2021, doi: 10.1016/j.ijleo.(2021).166933.
J. Ke et al., “Self-oscillating Triangular Pulses Generator Based on Dual-Parallel Mach-Zehnder Modulator,” Wirel. Opt. Commun. Conf., pp. 1–3, (2016).
J. Yuan, “An improved frequency-quadrupling triangular waveform generation based on external modulation and polarization control,” Results Phys., vol. 22, (2021), doi: 10.1016/j.rinp.2021.103885.
Y. Li, A. Wen, Y. Zhang, and M. Liang, “Photonic generation of frequency-doubled microwave waveform based on a PDM-MZM modulator,” Opt. Commun., vol. 458, no. 2, p. 124756, (2020), doi: 10.1016/j.optcom.2019.124756.
C. Wang et al., “Photonic generation of frequency-quadrupled triangular waveform based on a DP-QPSK modulator with tunable modulation index,” Opt. Laser Technol., vol. 137, no. April 2020, p. 106818, (2021), doi: 10.1016/j.optlastec.2020.106818.
H. Yutong et al., “Photonic microwave waveforms generation based on two cascaded single-drive Mach- Zehnder modulators,” Opt. Express, vol. 26, no. 6, pp. 3637–3644, (2018).
Y. Jiang et al., “Photonic microwave waveforms generation based on time-domain processing,” Opt. Express, vol. 23, no. 15, p. 19442, (2015), doi: 10.1364/OE.23.019442.
J. Li et al., “Photonic generation of triangular waveform signals by using a dual-parallel Mach–Zehnder modulator,” Opt. Lett., vol. 36, no. 19, p. 3828, (2011), doi: 10.1364/OL.36.003828.
Y. Gao, A. Wen, W. Liu, H. Zhang, and S. Xiang, “Photonic generation of triangular pulses based on phase modulation and spectrum manipulation,” IEEE Photonics J., vol. 8, no. 1, (2016), doi: 10.1109/JPHOT.2016.2522089.
W. Li, W. T. Wang, W. H. Sun, W. Y. Wang, and N. H. Zhu, “Generation of triangular waveforms based on a microwave photonic filter with negative coefficient,” Opt. Express, vol. 22, no. 12, p. 14993, (2014), doi: 10.1364/OE.22.014993.
J. Capmany, B. Ortega, and D. Pastor, “A Tutorial on Microwave Photonic Filters,” J. Light. Technol., vol. 24, no. 1, pp. 201–229, (2006).
W. Liu and J. Yao, “Photonic generation of microwave waveforms based on a polarization modulator in a sagnac loop,” J. Light. Technol., vol. 32, no. 20, pp. 3637–3644, (2014), doi: 10.1109/JLT.2014.2312819.
G.-F. Bai et al., “Versatile photonic microwave waveforms generation using a dual-parallel Mach–Zehnder modulator without other dispersive elements,” Opt. Commun., vol. 396, pp. 134–140, (2017), doi: 10.1016/j.optcom.2017.03.050.
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Copyright (c) 2022 Ramón Muraoka Espíritu, Arturo Arvizu, Juan de Dios Sánchez López, Francisco Javier Mendieta Jiménez, Joel Santos Aguilar
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