20 W splice-free erbium-doped all-fiber laser operating at 1610 nm

Abstract

We report on a splice-free erbium-doped all-fiber laser emitting over 20 W at a wavelength of 1610 nm, with a slope efficiency of 19.6 % and an overall efficiency of 18.3% with respect to the launched pump power at 976 nm. The simple cavity design takes advantage of fiber Bragg gratings written directly in the gain fiber through the polymer coating and clad-pumping from a single commercial pump diode to largely simplify the assembling process, making this cavity ideal for large-scale commercial deployment. Two single-mode and singly erbium-doped silica fibers were fabricated in-house: the first to assess the effects of a high erbium concentration (0.36 mol.% ErO), yielding a low efficiency of 2.5 % with respect to launched pump power, and the second to achieve the improved result mentioned above (0.03 mol.% ErO). Numerical simulations show the link between the performance of each cavity and ion pair-induced quenching.

Erbium-doped aluminophosphosilicate all-fiber laser operating at 1584 nm

“…At 1584 nm, the input coupler (HR-FBG) reflects 99.9% of signal, while the output coupler (LR-FBG) reflects 1% of it. It should be noted tat the Er 3+ -APS fiber was found to be significantly more photosensitive than the similar designed fiber solely codoped with Al 2 O 3 [17]. This allows for the inscription of high performance FBGs, as shown in Fig.…”

“…It can be observed in table 1 that clustering is significantly reduced in the aluminophosphosilicate fiber -the amount of paired ions remaining around 4% -even for a relatively high erbium ion concentration of 0.06 mol.%. In comparison with our previous work [17], erbium concentration is doubled while clustering is halved and the numerical aperture is kept low, which is enabled by the aluminum-phosphorous codoping. ions in the APS fiber were measured using the fiber preform and are presented alongside the lifetime measurement of the 4 I 13/2 level in Fig.…”

“…The preform was polished on two sides into a "double D" shape to favor pump absorption by inhibiting the propagation of poorly interactive circular modes [17]. The cladding to core aspect ratio was optimized to improve pump absorption while retaining a single-mode operation at the wavelength of emission (i.e.…”

“…The characterisation of the chemical and optical properties of the fiber drawn enabled us to perform numerical simulations following the ones described in ref. [17] in order to predict the optimal length of the active fiber and the optimal reflectivity of the output coupler. The signal output power at 1584 nm as a function of the fiber length and the output coupler's reflectivity is presented in Fig.3(a).…”

100-W-level single-mode ytterbium-free erbium fiber laser

“…A numerical model was developed in house in order to estimate the amount of paired ions in the fiber. This numerical model is the same as presented in [13], based on [22], and modified according to [23]. Multiple laser experiments using various fiber lengths as well as a thorough spectroscopic analysis of the core glass were performed to confirm the model's validity.…”