학술논문

Optical Vernier Effect Enabled Narrow Linewidth All-Fiber SBS-FWM-Based Tunable Optical Frequency Comb Generation
Document Type
Periodical
Source
IEEE Photonics Journal IEEE Photonics J. Photonics Journal, IEEE. 15(5):1-7 Oct, 2023
Subject
Engineered Materials, Dielectrics and Plasmas
Photonics and Electrooptics
Scattering
Optical pumping
Fiber nonlinear optics
Optical polarization
Optical scattering
Optical variables measurement
Couplers
Optical frequency comb (OFC)
stimulated brillouin scattering (SBS)
four-wave mixing (FWM)
optical vernier effect (OVE)
Language
ISSN
1943-0655
1943-0647
Abstract
In this paper, we experimentally demonstrate a low-power, broadband, and narrow linewidth SBS-FWM OFC with tunable line spacing of 50 to 600 GHz. The SBS-FWM OFC spans a bandwidth of $\approx$100 nm over the C$+$L-band region using $\approx$15 dBm pump power. The OFC is obtained by cascaded FWM process in highly nonlinear fiber (HNLF), seeded by SBS pumps in an all-fiber ring cavity setup. The linewidth of the SBS-FWM comb lines is measured to be $\approx$20 MHz which is largely determined by the SBS pump properties. By using the optical Vernier effect, the linewidth of comb lines is reduced by a factor of more than 2000 to below 20 kHz. We utilize the SBS-FWM OFC to study the performance of binary and 4-PAM transmission at 1 and 10 Gbps in a back-to-back (B2B) setup. The side-modes caused by the FP-cavity, formed by the HNLF modules in the ring cavity in our setup, affects the performance of the B2B transmission of PAM system.