Adjustable Bistability and Hysteresis Loop in a Nd:GdVO 4 Laser with an Intracavity Liquid Crystal Cell

Adjustable optical bistability and spatial hysteresis appearing in a Nd:GdVO 4 laser with an intracavity liquid crystal (LC) cell were achieved. On the basis of optically induced LC reorientations and the varying magnitude of the order parameter, two types of LC were used to easily control the characteristics of hysteresis with a single control variable. Using an electrically driven twisted-nematic LC, an adjustable hysteresis area as well as a switching-on pump power was demonstrated and periodic spatiotemporal patterns were observed. By contrast, amplified hysteresis loops were obtained by increasing the rotation angle of homogeneous LC cells with a nearly invariable switching-on pump power.