利用全息-离子束刻蚀工艺制作了工作波长为13.9nm的Laminar分束光栅。光栅的线密度为1000lp/mm,槽深13nm,占宽比0.43,Au膜厚度为40nm左右;当工作波长为13.9nm,入射角为81.2°时,其0级与-1级衍射光衍射效率乘积的最大值为8.1%,同时0级与1级衍射效率亦接近,约为27%和30%。实验结果表明,研制的Laminar光栅可用于13.9nm激光的分束,能够获得〉7%的分束效率。
A Laminar grating with a 1 000 lp/mm rectangular Laminar groove profile, 13 nm groove depth and a 0.43 duty cycle is fabricated by holographic ion beam etching. The grating is coated by Au in thickness of 40 nm. When the work wavelength is 13.9 nm, the product of the zero order and the first order light diffractions is close to 8.1% at an incident angle of 81.2°, and the diffraction efficiendes of the zero order and the first order are approximately equal. Experimental results illustrate the potential of Laminar grating as a beam splitter at 13.9 nm and also show its efficiency can be higher than 7 %.