A fiber laser with a comb-like spectrum

Mechanism of intrinsic wavelength tuning and sideband asymmetry in a passively mode-locked soliton fiber ring laser

“…The combination of a polarizer and the cavity birefringence forms a linear periodic-wavelength filter. In contrast to the cw and the actively mode-locked fiber lasers, 8,9 in order to achieve mode locking and to form a soliton in the laser cavity, the minima of the filter has to be inside the gain bandwidth of the gain medium. A mode-locked pulse is formed in the vicinity of the minima of the birefringent filter.…”

The use of the principal states of polarization to describe tunability in a fiber laser

“…where is the complex amplitude of the light field and are complex coefficients which are given by (4) The output field state of polarization, after a round trip in the fiber, is given by (5) where are the output PSP's at is the loss per unit length (polarization-independent), is the fiber length, is the optical phase gained by the " " PSP, and is the phase difference between the PSP's at the output. The formulation of the PSP's [8] claims that to firstorder in and 6where is the group delay difference between the PSP's (also called the polarization mode dispersion).…”

“…These phenomena lead to polarization mode dispersion in fiber-optics communication systems, which may limit system performance [2]. In fiber lasers, they can influence the spectrum of the laser, as has been demonstrated by devices such as a tunable fiber laser with an intracavity polarizer [3] and a fiber laser with discrete lasing modes (a "comb-like" spectrum) [4]. The properties of these special fiber lasers can be described with the usual Jones calculus, as in [5].…”