Optical anisotropy induced at five different wavelengths in azopolymer thin films: Kinetics and spectral dependence

Azopolymers are highly efficient materials, able to register the polarization state of light. They have broad range of applications from diffractive optical elements with unique polarization properties to biophysics. We present a study of birefringence kinetics, induced with five different pump lasers with wavelengths 355, 442, 491, 514 and 532 nm in thin films of widely used amorphous azopolymer PAZO - poly[1-[4-(3-carboxy-4hydroxyphenylazo)benzene sulfon amido]-1,2-ethanediyl, sodium salt]. During the real-time measurement, the value of the photoinduced birefringence (Delta n) is determined at 635 nm, using a DPSS laser. When saturation is reached, the spectrum of the birefringence is measured. Our results indicate that the investigated azopolymer can be used for applications in a wide wavelength range.