Word-record resolution has been achieved in a distance measurement using a femtosecond laser. Number of precise frequency modes of a femtosecond laser (optical comb) gives a series of radio wave frequencies as a result of intermode beat. Distance information is obtained by the phase measurement of the radio wave. Because of the broadband frequency of the femtosecond laser, highly stable beats up to GHz to THz are generated. High frequency is essential for ultrahigh-resolution in distance measurement. By comparison between two-color measurements, automatic compensation of environmental fluctuation in distance measurements is realized. Simple setup is attractive for industrial applications as well as length standard.
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Femtosecond-Comb Distance Meter in the optical testing tunnel at AIST.
The arrow in the photograph indicates the laser bea |
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| Relational Information |
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AIST Today Vol. 3, No. 4 (2003) 19
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No.9 Summer 2003
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