A Graduation Control Method In Ruling Engine For The Fabrication Of Varied Line-space Gratings With Sub-nanometer Space Increment

With the focal property and the aberration correcting ability, the varied line-space (VLS) grating has been successfully used in the areas of astronomical physics, synchrotron radiation, fiber communications and so on. Therefore, the ruling of the VLS grating is one of the greatest significant tasks of the grating fabrication. It is .a big problem to fabricate the VLS grating, considering its space increment varies within sub-nanometer. Hence, the grating ruling engines, in U. S. A, Japan or Russia, for VLS gratings have very complicated graduation control system. Although they have fabricated practical VLS grating, their costly devices don't adapt to the fabricating practice in our country.Since the space increment within nanometer or sub-nanometer is required, it is difficult to make it only by improving the precision of the graduation system. A phase scanning method for fabricating the VLS grating is suggested initially in this dissertation. The VLS grating can be ruled by scanning the interference fringes of the graduation system with a photoelectric sensor. The experiments show that the phase scanning method is right and innovative and the ability of the sub-nanometer space increment is reached. Since it only require an extra phase scanning device, the whole system has higher reliability and practicability.The main research work is shown as below:1. Summarize the focal property and aberration correcting ability of VLS plane grating.2. Accomplish the whole work of the photoelectric control system of the No. 2 ruling engine in CIOMP, including designing, making, fixing and debugging. Rebuild the control system of No. 4 ruling engine successfully.3. Put forward the phase scanning method for VLS grating and design the scanningdevice correspondingly.4. Make the ruling experiments for VLS grating using the phase scanning method. Analyze the ruling error primarily.5. Examine the factual space of the experimental VLS grating sample.