Novel Multiwavelength Erbium-Doped Fiber and Raman Fiber Ring Lasers With Continuous Wavelength Spacing Tunability at Room Temperature

• Published in: Journal of lightwave technology Vol. 25; no. 8; pp. 2219 - 2225
• Main Authors: Young-Geun Han, Ju Han Lee, Sang Bae Lee, Poti, L., Bogoni, A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Applied sciences; Bragg gratings; Circuit properties; Detection, estimation, filtering, equalization, prediction; Electric, optical and optoelectronic circuits; Electronics; Erbium-doped fiber lasers; Exact sciences and technology; Fiber gratings; Fibers; Fundamental areas of phenomenology (including applications); Information, signal and communications theory; Integrated optics. Optical fibers and wave guides; Laser optical systems: design and operation; Laser stability; Laser tuning; Lasing; Multiwavelength erbium-doped fiber (EDF) laser; multiwavelength fiber laser; multiwavelength Raman laser; Noise levels; Optical and optoelectronic circuits; Optical control; Optics; Physics; Pump lasers; Raman lasers; Resonators, cavities, amplifiers, arrays, and rings; Ring lasers; Signal and communications theory; Signal, noise; Stimulated emission; superimposed chirped fiber Bragg grating (CFBG); Telecommunications and information theory; Temperature; Tuning; wavelength spacing tunability; Wavelengths; Integrated optics; Tunable circuit; Fiber laser; Dispersion shifted fiber; Non linear optics; Bragg grating; Multiwavelength erbium-doped fiber (EDF) laser; Ring laser; Multichannel filter; multiwavelength Raman laser; Erbium addition; Cavity resonator; Optical fiber; superimposed chirped fiber Bragg grating (CFBG); Chirp; Doped materials; wavelength spacing tunability; Grating in fiber; Solid state laser; Stimulated Raman scattering; Ring resonator; Optical amplifier; Optical dispersion compensation; Gain; Room temperature; multiwavelength fiber laser; Signal to noise ratio
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2007.901341

In this paper, we investigate a flexibly tunable multiwavelength fiber ring laser with a continuous wavelength spacing tunability, incorporating a superimposed chirped fiber Bragg grating (CFBG) at room temperature. We exploit versatile gain media such as erbium-doped fiber (EDF) and Raman amplifiers in generating the multiwavelength fiber ring laser. The wavelength spacing of a superimposed CFBG can be continuously controlled by modifying the chirp ratio of the grating with the specially designed apparatus. After configuring a fiber ring cavity with the proposed multichannel filter, we realize stable multiwavelength fiber ring lasers at room temperature, which are based on an EDF amplifier incorporating a highly nonlinear dispersion-shifted fiber or a Raman amplifier using a dispersion-compensated fiber. Power fluctuation is less than ~0.6 dB. No lasing wavelength change is severally observed for the whole tuning range. For the multiwavelength EDF laser, stable 11-wavelength simultaneous operation spaced at 0.51 nm, with a signal-to-noise ratio (SNR) of more than ~45 dB at room temperature, is achieved. A high-quality multiwavelength Raman laser output with stable 30 lasing wavelengths spaced at 0.51 nm with a high SNR of more than ~45 dB is also realized. By applying the proposed tuning technique to both the multiwavelength EDF and Raman lasers, a wide and continuous tunability of lasing wavelength spacing is successfully achieved, which is measured to be ~ plusmn0.033 nm/mm. By controlling the pump power in the multiwavelength Raman fiber ring laser, we can control the number of lasing channels at a wavelength spacing of 0.51 nm.