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Improving the surface quality of the ZnGeP2 crystal is an important way to expand its application range. Given the high difficulty of processing the ZnGeP2 crystal, the research proposed a method of increasing the processing temperature of the material to expand the range of the plastic region, then improving the surface quality, the feasibility of the method was verified by heating assisted nanoindentation experiment and molecular dynamics simulation. The use of diamond tools to scribe the surface revealed the microscopic morphology changes of the ZnGeP2 crystal under high temperatures. Finally, with the assistance of heating, the surface of ZnGeP2 crystal was processed comprehensively by ultra-precision diamond fly-cutting machine, the experimental results showed that as the processing temperature increased, the surface quality of the ZnGeP2 crystal gradually improved, and the surface roughness Sa could reach to 9.426 nm. The effectiveness of improving the surface quality through heating assisted cutting was verified, which had guiding significance for the processing of other hard and brittle materials.

To satisfy the high-stability requirement of a tiled grating, we have analyzed and optimized the stability of a newly designed precise tiled- grating device considering three aspects: structure design, transmission chain, and control algorithms. The main structure of the device is changed from a parallel-board structure to a new tetrahedral brace design, enhancing the overall vibration stability; during the analysis of the transmission chain, the adjustment accuracy and stability of the device were ensured by slowing the growth of the error transmission factor; and for the optimization analysis of the PID control algorithms, we adopted a latch compensation method to avoid the saturated loss and a four-point central difference method to avoid the disturbances, thus enhancing the stability control of the device. To test the stability of the device, an optical experiment with a reference spot was designed. The experimental results showed that over 380 s, the ambient excitation response was always within an acceptable range. The average deflections about the X axis and Y axis are 0.243 and 0.00146 microrad, respectively, which satisfy the stability requirement. Za izboljšanje stabilnosti deljenih mrežic, ki so se uveljavile pri gradnji metrskih večslojnih dielektričnih (MLD) uklonskih mrežic kot ključna komponenta kompresorja v laserskem sistemu CPA, smo razvili natančno deljeno mrežico in analizirali njeno stabilnost. Stabilnost deljene mrežice je namreč eden najpomembnejših dejavnikov uspeha laserskega eksperimenta. Za izboljšanje konstrukcijske stabilnosti smo zasnovali deljeno mrežico v obliki tetraedra, ki izboljšuje vibracijsko stabilnost naprave. Za zmanjšanje vpliva naraščajočega faktorja prenosa napak smo dodali navidezno stojalo v oporo mrežici. Deljena naprava se tako izogne območju s hitro naraščajočimi faktorji prenosa napak ter zagotavlja dobro natančnost nastavitve in stabilnost. Za povečanje stabilnosti krmiljenja smo izboljšali krmilne algoritme PID po dvotočkovni shemi: 1) metoda zaklenjene kompenzacije preprečuje nasičene izgube zaradi integriranega nasičenja, in 2) metoda štiritočkovne osrednje razlike omogoča pridobitev parametrov razlik pri odpravljanju motenj.

Displacement measurement is one of the most important parameters to be monitored.A Fiber Bragg Grating(FBG) displacement sensor based on double cantilever beams is developed,in which the displacement is changed to wavelength shifts of two FBGs.The influence resulted from temperature to displacement measurement is reduced by the differential of the two wavelengths,since they have the same wavelength shifts when they are in the same environment.The operation principle based on FBG theory is deduced,and the reasons of measurement error are analyzed.Experimental results show that the displacement sensitivity is 123 pm/mm in the range of 0~20 mm,and the temperature cross-sensitivity is 17 μm/℃ after temperature compensation.With the particular advantage,this FBG displacement sensor may find tremendous applications in engineering.