Study on thermal-lens induced mode coupling in step-index large mode area fiber lasers

Near-diffraction-limited operation of step-index large-mode-area fiber lasers via gain filtering.

We present, for the first time to our knowledge, an explicit experimental comparison of beam quality in conventional and confined-gain multimode fiber lasers. In the conventional fiber laser, beam quality degrades with increasing output power. In the confined-gain fiber laser, the beam quality is good and does not degrade with output power. Gain filtering of higher-order modes in 28microm diame...

Filamentation analysis in large-mode-area fiber lasers

Starting from the paraxial wave equation, an analytic expression for filament threshold in fiber lasers is derived. The occurrence of filamentation is determined by the larger of two thresholds, one of perturbative gain and one of spatial confinement. The threshold value is approximately a few megawatts, depending on the parameters of the fiber. © 2007 Optical Society of America OCIS codes: 060...

Large mode area Yb - doped photonic bandgap fiber lasers

Large mode area Yb-doped photonic bandgap fiber lasers Report Title Fiber lasers are in the process of revolutionizing modern manufacturing. Further power scaling is still much desired to increase throughput and to break new frontiers in science and defense. It has become very clear now that highly single-mode fibers with large effective mode areas are required to overcome both nonlinear effect...

Single mode PT symmetric large area lasers

We experimentally demonstrate single longitudinal mode operation in microring laser using the concept of PT symmetry. A PT-symmetric coupled resonator arrangement can considerably enhance the maximum achievable gain of single mode microring cavity. The method is broadband thus work well for inhomogenously broadened gain mediums. It doesn’t rely on any additional component to ensure its mode sel...

Mode Locked Fiber Lasers