Influence of end reflectivity on the excess-noise factor indistributed feedback lasers

The influence of end reflectivity on the excess noise factor in distributed feedback lasers is analyzed. It is shown that the end reflectivity affects the excess-noise factor markedly in the weak and moderate coupling region. In particular, in this coupling region the noise level in the laser structure strongly depends on the end reflectivity phase. Moreover, in the weak and moderate coupling region, the excess-noise factor decreases with an increasing end reflectivity amplitude; in the strong coupling region the opposite behavior is observed     

Excess noise factor in laser with extra cavity devices

The effect of the nonorthogonality of the longitudinal eigenmodes in laser with an extra cavity device described by the extra cavity distributed losses, is analyzed. An expression for the excess noise factor is derived. It is shown that the extra cavity devices changes remarkably the behaviour of the noise characteristics in comparison with conventional two-mirror laser