超精密平面研削による無機非線形光学結晶KDPの光学面創成

抄録

Potassium dihydrogen phosphate (KH₂PO₄) called KDP was ground by an ultraprecision surface grinder having a glass-ceramic spindle. of extremely-low thermal expansion with various cup-type resinoid-bonded diamond wheels under various grinding fluids. Grinding fluid is a key factor of performing ultraprecision grinding of KDP crystal, because the crystal is extremely deliquescent. The grinding modes such as ductile, ductile & fracture, and fracture modes are affected by the grinding speed, depth of cut, feed per wheel revolution, average grain size of diamond wheels. The surface roughness depends upon the grinding direction, grain size, feed per wheel revolution, viscosity of silicone oil and kind of alcohol as an additive. The optical surface of 0.553nm rms, 3.40nm Ry in surface roughness, measured with TOPO-2D, 40×has been obtained by using SD5000-75-B diamond wheel after grinding of LHG-8 laser glass with a mixture of 10cSt silicone oil and 5wt% heptanol as grinding fluid.