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Date: 20-1-2021
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Sum- and Difference-Frequency Generation
Two waves of comparable intensity and frequency ω1 and ω2 are initially present, and a wave at the third frequency ω3 is created through the nonlinear interaction
P(ω3) = ∈0 χ(2)E(ω1)E(ω2), .........(1)
where ω3 = ω1+ω2. Similarly, a wave at the difference frequency ω3−ω2 = ω1 may be generated (ω3 > ω2 > ω1). A very common technique to produce the third harmonic of a neodymium laser is, first, the generation of the second harmonic and then sum frequency generation by mixing the second harmonic (ω2) with the unconverted portion of the fundamental beam (ω1).
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علامات بسيطة في جسدك قد تنذر بمرض "قاتل"
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أول صور ثلاثية الأبعاد للغدة الزعترية البشرية
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مدرسة دار العلم.. صرح علميّ متميز في كربلاء لنشر علوم أهل البيت (عليهم السلام)
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