Hello, I am coming from the fields of diffractive optics and I have the following questions: I would like to etch microstructures into a fused silica substrate with a wet chemical etch process. I have heard that HF/NH4F is appropriate to do that. The structures have lateral feature sizes of 1-10 microns. The elements should be etched approximately 1-2 micron deep. Has anyone made experience with similar processes and even fabricated diffractive optical elements in quarz glas? For an answer I would be grateful. Thanks in advance Daniel