摘要 |
An apparatus for providing a pulsed radiation beam has a radiation source providing a pulsed radiation beam at a constant pulse repetition frequency. A beam deflector in the path of the pulsed radiation beam is actuable to redirect the pulsed radiation beam cyclically towards each of a plurality of beam intensity modulators in turn. A beam recombiner combines modulated light from each of the plurality of beam intensity modulators in order to form the modulated pulsed radiation beam at the constant pulse repetition frequency.
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