| Autor: |
Haas, Roger A., Summers, Mark A., Linford, Gary J. |
| Zdroj: |
Optics Letters; October 1986, Vol. 11 Issue: 10 p620-622, 3p |
| Abstrakt: |
Experiments and analysis indicate that graded random phase modulation can be used to apodize a laser beam. In the case of an obscuration or a hard edge it can prevent the formation of Fresnel-diffraction ripples. For example, here the interaction of a 1-μm-wavelength laser beam with a central obscuration of half-width a = 100 μm is studied theoretically. It is found that if the exit surface of a window, placed immediately downstream of the obstacle, is randomly modulated with a Gaussian amplitude transverse correlation length l = 50 μm and a mean-square amplitude that decreases exponentially from a peak height of ~1 μm^2 away from the center of the obscuration with transverse scale length L = 500 μm, then the Fresnel-diffraction ripples normally produced by the obscuration are eliminated. The scaling of these results is also discussed. The calculations are in general agreement with experimental results. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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