EUV only uses reflective mirrors not lens due to lens made of fused silica which absorbs EUV light.
The mirror is about 40 layers of alternate Mo/Si and each layer is 6.8nm thick.
The surface of the mirror has to be very smooth , no more than 0.2nm RMS.. meaning the unevenness of the mirror is a few atoms thick.
0.2nm RMS means only allow 2 atoms difference.
Have to use ion beam to "sand" the layer to remove extra atoms.
That's why its super difficult to make mirror for EUV optics. All optics vendors in China i talked to have not even heard such things ,