Glan Taylor Polarizer is made of two same birefringence material prisms which are separated by an air space. The polarizer with on side escape window is suitable for low to medium power application. Glan Taylor Polarizer will divide an entering unpolarized beam into beam rays, one is the extraordinary that is transmitted through the other side, and another is the ordinary ray that is totally internally reflected absorbed.  
Glan-Taylor polarizers are designed as polarizer elements that remove the reflected ordinary polarization component of a beam.  A significant amount of reflected light escapes the polarizers through the side port, including all of the ordinary ray and some of the extraordinary ray. As such, the escape beam is not fully polarized, and only the transmitted extraordinary ray should be used for applications that require a high-quality, polarized beam.
They are only designed to work with well collimated light beams; converging and diverging input beams will not exhibit proper polarization and incidence angle at the internal interface.