Fabrication of varied-line-spacing grating by elastic medium

We demonstrate a method of fabricating varied-line-spacing grating by employing elastic medium with variable vertical section. The advantages of this technique include continuous variation of line spacing, high fabrication efficiency, low cost, etc. It is very difficult or impractical to produce this variation of line spacing by traditional interference lithography. This kind of grating can be used in an optical position sensor to improve the precision of the sensor.