On the optical frame, the use of light division system and polarized optical components improve the head-to-scale tolerance substantially and produce four interference quadrature signals.

• 光学架构上，本光学尺利用分光系统以及偏极光学元件，能大幅提高光栅与光学头间之对位公差，并获得四正交之光学干涉讯号。