| 摘要 |
The present invention is directed at a coherence test reticle or lightographic plate, and a corresponding method for testing the coherence of a laser beam using by illuminating the test reticle and the recording and/or analyzing the optical patterns generated by the illumination. The technique was designed for, but not limited to, the characterization of laser-based systems via the detection of optical radiation modulated by transmissive, reflective and diffractive patterns printed on a reticle or lithographic plate designed specifically for this purpose. Spatial coherence and longitudinal or temporal coherence may be measured independently. Vertical and horizontal coherence may be measured independently. The technique is focus error insensitive. That is to say, the focus errors will be recorded by the technique in a deterministic fashion and can be removed from the data. The robustness and convenience of the technique is driven by the single plate with no optical alignment, making the technique easily implemented in the field.
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