Cavity Wavelength on Erbium-Doped Fiber Ring Laser Depending on Fabry–Pérot Etalon Steering Angle

• Published in: Applied Sciences
• Main Authors: Cheng-Kai Yao, Ting-Po Fan, Ming-Che Chan, Peng-Chun Peng
• Format: Article
• Language: English
• Published: MDPI AG 2025-01-01
• Subjects: erbium-doped fiber ring laser; Fabry–Pérot etalon; liquid crystal
• Online Access: https://www.mdpi.com/2076-3417/15/2/822

This study presents the liquid crystal Fabry–Pérot etalon (LC-FP) as the preferred laser wavelength tuning solution within a erbium-doped fiber ring laser architecture. The laser cavity wavelength can be adjusted by applying varying voltages to the LC-FP. Furthermore, tuning the laser wavelength can be facilitated by modifying the incident light through changes in the steering angle of the LC-FP, which is attributed to the angular dispersion characteristics of the device. The operational range for the steering angle of the LC-FP is ± 4 to 18 degrees. This architectural framework is adept at facilitating the generation of single-wavelength and dual-wavelength lasers within the C band. The tunable range for a single wavelength is approximately 13 nm, while the tunable range for dual wavelengths is around 14 nm, with a wavelength spacing of approximately 17.5 nm. These capabilities are primarily influenced by the operational wavelength of the erbium-doped fiber amplifier (EDFA), the operating wavelength of the collimator that directs the fiber optic beam into the LC-FP, and the fixed thickness of the LC-FP.