| 摘要 |
An interferometer for rapidly measuring the phase profile and intensity distribution of a high powered continuous wave laser beam. The optical wave front to be measured is re-imaged on the surface of a rotating drum containing pairs of closely spaced apertures which rapidly scan the optical wave front and produce two radiation beams that interact to generate an interference fringe pattern in accordance with the principle of Young's two-slit interferometer. The interference pattern is focused on the surface of a high-speed optical chopper containing slits equal to half the width of each interference fringe pattern and the fringe radiation passing through the slits is detected by a transducer that generates an electrical sinusoidal output signal having a frequency corresponding to the chopper modulating frequency, but phase-shifted left or right by an amount corresponding to phase variations in the scanned wave front. These phase variations are measured by comparing them with a stable electrical signal having exactly the same period as the IR signal produced by chopping and detecting the output of an internally generated reference beam.
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