کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5367591 1388368 2009 4 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Investigation of thermo-mechanical behaviour of diffractive optical elements for CO2 lasers
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
Investigation of thermo-mechanical behaviour of diffractive optical elements for CO2 lasers
چکیده انگلیسی

Phase diffractive optical elements are at present proposed for use with infrared high power lasers, for material surface treatment applications. However, the heating of the component exposed to several kilowatts per square centimetre can be a problem for practical implementation. The deformations due to thermal expansion of a gold binary diffraction grating under high power CO2 laser exposure at 10.6 μm are estimated by a Finite Element Method. They are compared to the geometrical tolerances obtained by a rigorous electromagnetic Fourier modal method which is used to calculate the optical performances. Several exposure parameters (duration, average laser power) and grating parameters (period, line space ratio) are investigated. The laser exposure should be limited to a few milliseconds with a power density on the grating of 104 W/cm2, so that the amplitude of the deformations does not exceed the 75 nm tolerance on the grating depth. One is thus assured that the diffraction efficiency in the first order remains superior to 38.5%.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 255, Issue 10, 1 March 2009, Pages 5507-5510
نویسندگان
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