3D mapping of the output laser beam from a PDLC sample

Self-transparency due to thermal non-linearities is presented as a basic sw itching effect in a thick polymer dispersed liquid crystal sample. For the first time a detailed 3D mapping of the output laser beam as a function of the x-y coordinates is presented: changes of the transmitted beam profile a re recorded vs, both incident power and time. It is discussed how light int ensity and temperature can be used as control parameters for the non-linear part of the refractive index. The experimental results confirm the existen ce of a threshold value of the incident light intensity at which the device switches from the scattering state to the transmissive state.