Most thin sheets of polyester actually function as retarders (not necessarily quarter wave plates) due to the way their molecules are aligned during manufacturi

Most thin sheets of polyester actually function as retarders (not necessarily quarter wave plates) due to the way their molecules are aligned during manufacturing. Here's one of the better cites on the topic, it includes some math to design any desired retarder: http://arxiv.org/pdf/physics/0702225.pdf http://arxiv.org/pdf/physics/0702225.pdf