Investigation of nonlinear and thermal effects of high power pulsed laser isolators

The influences on the isolation of the optical isolators in pulsed laser situation are theoretically analyzed, including magneto-optical crystals photoelastic effect caused by temperature gradient on cross section, extinction ratio and Kerr effect, and compared with those in continuous laser situation. The result shows that, in the situation of the same average power, pulsed laser has a lower isolation than continuous laser. When the average power is low, extinction ratio has a larger effect on isolation;when the average power is high, the effect of extinction ratio is limited, and the photoelastic effect is the main effect on isolation. When the peak power density is high, Kerr effect reduces the isolation a lot. And Kerr effect could reduce the isolation more with increasing the peak power density.