For high energy, ultrafast laser applications, common polarizer technologies used for variable attenuation do not fulfill the complete set of requirements to extinction ratio, transmission level, bandwidth, transmitted wavefront distortion, GDD ripple and energy handling capability. For these applications, and initially developed solely for Ti:sapphire wavelengths, Ibsen offers a unique, grating-based polarizer. The polarizer is 100% fused silica, with the polarizing grating being a surface relief, etched grating structure with no thin-film coatings of any kind.
We offer pattening and etch of grating structures on fused silica or other materials, applying Ibsen’s unique know-how:
The grating polarizer transmits close to 100% of the incoming TM (p) polarized light, while the TE(s) polarized light is diverted into other diffraction orders (primarily -1T but also a few percent into reflected orders.)
In order to use the grating polarizer as a variable attenuator, either rotate the grating or the incoming, linearly polarized light so that the ratio of TM:TE provides the wanted attenuation.