Full-positive-dispersion er-doped optical-fiber laser device based on optical-grating filtering and adjustment method thereof

Abstract

The invention discloses a full-positive-dispersion er-doped optical-fiber laser device based on optical-grating filtering and an adjustment method thereof. The full-positive-dispersion er-doped optical-fiber laser device includes a polarization beam-splitting prism, an isolator, a first 1 / 4 wave plate, an optical grating, a first collimator, a gain fiber, a second collimator, a second 1 / 4 wave plate and a 1 / 2 wave plate so that an annular resonance cavity is formed. A pumping source is coupled to the gain optical fiber through a wavelength division multiplexer. A coupler is connected to the second collimator through the optical fiber. An optical grating is inserted into the annular resonance cavity and the optical grating is used as a filter in the resonance cavity. Through adjustment of the transverse position and the angle of the first collimator, the direction of the first collimator is adjusted so that diffraction light of a specific center wavelength enters the collimator and thus a self-locking mode of the laser device is realized through filtering; and the distances between the first collimator and diffraction points of the optical grating are adjusted so that adjustment of the spectral width of output pulses is realized.

Description

technical field [0001] The invention relates to a fiber laser, in particular to a control method for a total positive dispersion erbium-doped fiber laser for mode locking by using a grating as a laser cavity filter. Background technique [0002] Single-mode fiber lasers were born in the mid-1980s, and truly stable ultrashort-pulse fiber lasers (20ps) appeared in 1989. In recent years, with the development of solid-state femtosecond lasers, femtosecond-level fiber lasers have also appeared, and become a strong competitor of femtosecond solid-state lasers. Its biggest advantages are miniaturization, high efficiency, energy saving, and good stability. [0003] The pulse formation mechanism in fiber lasers has gone through several stages from soliton type, stretching-squeezing type, self-similar type to total positive dispersion or amplified self-similarity. People's understanding of the mode-locking and pulse formation mechanism of fiber lasers is also improving . Fiber lase...

AI Technical Summary

Problems solved by technology

However, single-mode fiber produces negative dispersion in the 1.5μm band, so it is difficult to realize a fully positive dispersion fiber laser

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