[Show abstract][Hide abstract] ABSTRACT: In this paper we propose a new type of fibre laser configuration
which consists of closing an erbium-doped fibre laser cavity by two
Bragg gratings (similarly to DBR laser). One of the grating has a Π/2
phase shift at the centre. In the case of passive fibre long Bragg
grating with a Π/2 phase shift has narrow transmission peak in the
centre of the reflection spectrum. In an active fibre, the spontaneous
emission spectrum below threshold exhibits a maximum at the place of the
peak in the centre of the reflection spectrum. That would give
possibilities to obtain single-frequency oscillation with high output
power provided by the long length of the laser cavity
[Show abstract][Hide abstract] ABSTRACT: A double-clad single-mode neodymium fibre laser was constructed. The cw output power of the laser was 3 W at the wavelength of 1.06 μm. The fibre laser was pumped by a fibre-coupled diode laser array. The efficiency of the fibre laser was 43%.
No preview · Article · Jan 1997 · Quantum Electronics
[Show abstract][Hide abstract] ABSTRACT: For the first time "viscous fingers" along the core-cladding boundary were detected in the fiber preforms with high concentration of Ge and Al in the core. The "viscous fingers" deform the waveguide structure and can cause the additional loss. The proposed theoretical model and observation of viscous fingers allow one to explain the origin of additional optical losses in fibers based on glasses with different viscosities. Also we can make several proposals to decrease these additional losses. The most obvious recommendation consists in matching of the viscosities of core and cladding.