Researchers have solved the problem of low modulation depth of saturable absorber by preparing Graphene micro fiber composite structure through optical deposition

Passive Mode locking uses the nonlinear absorption effect of saturable absorber to adjust the loss and phase of the cavity, thus generating mode-locked pulses. Graphene has unique band gap structure, low absorption coefficient, considerable modulation depth and ultra wide operating spectrum range (300-2500 nm).

Graphene has become an ideal saturable absorber for ultrashort pulse output of fiber lasers. Researchers have successfully carried out many experiments on Graphene Mode locking and realized mode locking pulse. Various bright pulses have been reported, and laser pulses can also be divided into bright and dark pulses based on energy distribution patterns.

Researchers led by Professor Li Mingyu of Changchun University of Science and Technology are interested in Graphene mode locked fiber lasers. Their idea is to prepare Graphene micro fiber composite structure by optical deposition method to achieve full fiber structure and solve the problem of low modulation depth of saturable absorber.

The paper "Mode locking generation of conventional solitons and bright dark solitons in Graphene mode-locked fiber lasers" has been published in Frontiers of Optoelectronics.

In this way, a Graphene mode-locked fiber laser is constructed in the negative dispersion region, and the output characteristics of two switchable mode-locked pulses in the Graphene mode-locked fiber laser, the influence of pump power and polarization state on brightness and darkness are studied. Studied soliton pairs and dual wavelength tunable characteristics. This research will further expand the application of Graphene in fiber lasers.

Source: Laser Network