Distributed feedback fiber laser based on a fiber Bragg grating inscribed using the femtosecond point-by-point technique

Abstract

A distributed feedback (DFB) fiber laser based on a 32-mm long pi-phase-shifted fiber Bragg grating inscribed using the femtosecond point-by-point technique in a single-mode erbium-doped optical fiber (CorActive EDF-L 1500) is demonstrated. The lasing power of the DFB laser reaches 0.7 mW at a wavelength of 1550 nm when pumped with a laser diode at a wavelength of 976 nm and power of 525 mW. The width of the lasing spectrum is 17 kHz. It is shown that the pi-phase-shifted fiber Bragg grating fs-inscribed in a non-PM fiber provides the selection of the single polarization mode of the DFB laser. DFB laser formation in a highly doped non-photosensitive optical fiber (CoreActive SCF-ER60-8/125-12) is also demonstrated.

Advanced distributed feedback lasers based on composite fiber heavily doped with erbium ions

“…3a. This behavior is typical for resonators inscribed by femtosecond laser radiation and point-by-point writing technique 27 , where FBG's coupling coefficient is different for different polarization axes. More precise self-heterodyne measurements give the value of beat-signal spectral width of about 70 kHz at a level of − 20 dB, which corresponds to the laser linewidth of 3.5 kHz (Fig.…”

“…2 shows the transmission spectra of the inscribed phase-shifted FBG, which were measured for different polarization axes using an Apex AP2050 optical spectrum analyzer with a resolution of 1 pm, as well as the spectra obtained by numerical simulation. From their comparison one can see that the fast axis of the FBG has a higher coupling coefficient than the slow one, which is associated with the peculiarity of the method of femtosecond point-by-point inscription 26,27 . Numerical simulation with coupling coefficients κ fast = 1,357 m −1 and κ slow = 1,115 m −1 for the fast and slow axes respectively agrees well with the corresponding experimental spectra, despite the limited dynamic range at measuring the transmission spectra of the phase-shifted FBG.…”

Symmetric Step-Apodized Distributed Feedback Fiber Laser With Improved Efficiency

“…Over the past decades, distributed feedback (DFB) fiber lasers have a number of applications in coherent optical communications [1], fiber-optic sensors [2]- [4], and microwave signal generation [5] due to the advantages of single-mode operation, narrow linewidth, low noise, and high stability [6]- [9]. DFB fiber lasers are typically fabricated by optically pumping an active cavity consisting of a phase-shifted fiber Bragg grating (PS-FBG) inscribed directly in a section of rare-earth-doped fiber.…”

5-мм лазер с распределенной обратной связью на основе композитного Er3+ волоконного световода

“…В спектре генерации наблюдалась одна поляризационная мода, что является особенностью резонаторов, изготовленных с применением фемтосекундной технологии [9]. Порог генерации достигался при относительно высокой мощности накачки ≈ 75 мВт, в данном случае это связанно с малым временем жизни атома на метастабильном уровне (3,5 мс).…”