• Chinese Journal of Lasers
  • Vol. 52, Issue 10, 1006005 (2025)
Jian Tang, Mingliang Peng, Xiaoyang Lei, Jiyuan Huang..., Huankai Zhang, Aiai Jia, Jixun Liu, Lingxiao Zhu, Shuhua Yan, Guochao Wang* and Jun Yang**|Show fewer author(s)
Author Affiliations
  • College of Intelligence Science and Technology, National University of Defense Technology, Changsha 410073, Hunan , China
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    DOI: 10.3788/CJL241263 Cite this Article Set citation alerts
    Jian Tang, Mingliang Peng, Xiaoyang Lei, Jiyuan Huang, Huankai Zhang, Aiai Jia, Jixun Liu, Lingxiao Zhu, Shuhua Yan, Guochao Wang, Jun Yang. Theory, Progress, and Application of Optical Single Sideband Modulation Technology[J]. Chinese Journal of Lasers, 2025, 52(10): 1006005 Copy Citation Text show less

    Abstract

    Significance

    As an important electro-optical modulation technique, the optical single sideband (OSSB) modulation technique has been widely used in the fields of laser communication, LIDAR, quantum optics, and quantum sensing owing to its advantages of easy electro-optical detection, low signal noise, and high spectral efficiency. For example, in optical communication, the OSSB modulation technique not only overcomes the power-fading problem caused by the mutual interference of phases of two sidebands in optical double sideband (ODSB) modulation but also improves the system receiving sensitivity and antidispersion ability, thus providing effective technical support for broadband communication. For cold atomic interferometry, OSSB modulation technology eliminates the adverse effects of redundant sidebands introduced by phase modulation, thus resulting in low phase noise and pure spectral Raman light. It is conducive to more accurate control of the atomic phase, reduces the effect on the accuracy of cold atomic interference, and improves the contrast of interference stripes. Consequently, the accuracy of cold atom interferometry has been significantly improved. OSSB modulation technology has been realized through various schemes, including optical filtering, phase-shift interference, and other methods. However, this technology has not been summarized systematically; therefore, its theory, progress, and application must be reviewed.

    Progress

    The optical-filtering method achieves OSSB modulation by filtering out the sideband of the ODSB signal. This method primarily utilizes fiber Bragg gratings (FBGs) and micro-ring resonators (MRRs) for optical-frequency screening to generate OSSB signals. Both techniques suppress specific sidebands through precise spectral selection to obtain the desired single-sideband signal. The fiber gratings typically used in optical filtering are uniform fiber Bragg gratings (UFBGs), phase-shift fiber gratings (PS FBGs), and Fabry?Perot fiber gratings (F-P FBGs). The refractive-index change amplitude and change period of the UFBG fiber core remain constant, and the bandwidth of the reflection spectrum is between 0.1 nm and 0.2 nm. Both PS FBGs and F-P FBGs are fabricated based on UFBGs. Extremely narrow filtering is achieved by introducing a phase-shift point or Fabry?Perot interferometer. The filtering bandwidths of the PS FBG and F-P FBG can reach less than 1 pm, which are three orders of magnitude higher than that of the UFBG, thus resulting in better filtering performance. The small footprint of the MRR allows it to be easily integrated into a single chip or photonic integrated circuits, thus enabling highly integrated optical systems. Additionally, the filtering characteristics of the MRR can be adjusted by fine-tuning the size of the ring or the environmental conditions, which provides a certain degree of flexibility. However, when the input power is extremely high, the MRR may exhibit nonlinear effects, such as four-wave mixing, which deteriorates its filtering performance. Moreover, the filtering bandwidth of the MRR is limited by its quality factor, which renders it difficult to achieve a wider bandwidth. Both the FBG and the MRR are sensitive to the ambient-temperature change, which results in transmission spectral drifts and affects the modulation. Thus, temperature control is required to stabilize the filtering characteristics. This paper summarizes the research status of OSSB modulation techniques based on the optical-filtering method (Table 1).

    The phase-shift interferometry method allows different beams to coincide and interfere in space by setting the driving conditions of the electro-optic modulator [dual-drive Mach-Zehnder modulator (DDMZM) or in-phase and quadrature (IQ) modulator] and precisely controlling the phases of different branched light waves; subsequently, the OSSB signal is generated by precisely controlling the phase difference. The DDMZM-based OSSB modulation can operate in a wide operating bandwidth for applications in different frequency ranges, thus allowing a large modulation depth to be realized. The DDMZM offers high filtering flexibility. However, it is easily affected by the external environment, thus resulting in subpar filtering stability. Therefore, the modulator filtering performance must be stabilized via temperature control; however, this increases the system complexity. Moreover, the OCSR of the OSSB signal generated by this method depends only on the modulation index, which renders further performance optimization challenging. The IQ modulator-based OSSB modulation technique allows the OCSR to be tuned within a wide range by controlling the bias voltage and the power of the radio frequency drive signal. However, the IQ modulator has a complex structure and requires multiple drive circuits. Moreover, its optical transmission loss can exceed 20 dB. Meanwhile, the electro-optic modulator is easily affected by the external environment, thus causing the optimal operating point to drift; however, this can be overcome via automatic bias control. We summarize the main technical indicators of the OSSB modulation technique based on phase-shift interferometry in Table 2.

    In addition to the methods above, OSSB modulation can be realized using Serrrodyne modulation, Sagnac interferometry, stimulated Brillouin scattering, and electro-absorptive modulation methods, which have been demonstrated experimentally.

    Conclusions and Prospects

    This paper reviews the research progress of OSSB modulation techniques. We first introduced the OSSB signal characteristics and modulation methods; subsequently, we described the principles and research progress of each modulation method. By systematically reviewing the related literature, we focused on analyzing and comparing the principles of the optical-filtering and phase-shift interferometry methods as well as their main technical indicators. Combined with other OSSB modulation methods, we elaborated the current status of their applications as well as their development trends and technical bottlenecks. Additionally, we highlighted the key development direction of on-chip integrated OSSB modulators. Owing to the rapid development of thin-film lithium niobate platforms, the prospect of fabricating large-bandwidth high-performance electro-optical modulators based on thin-film lithium niobate materials is promising.

    Jian Tang, Mingliang Peng, Xiaoyang Lei, Jiyuan Huang, Huankai Zhang, Aiai Jia, Jixun Liu, Lingxiao Zhu, Shuhua Yan, Guochao Wang, Jun Yang. Theory, Progress, and Application of Optical Single Sideband Modulation Technology[J]. Chinese Journal of Lasers, 2025, 52(10): 1006005
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