| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a distance measuring device capable of accurately measuring the distance to a measuring object, regardless of the distance to the measurement object. Ž<P>SOLUTION: Each optical pulse LDs is emitted at a fixed interval from a light source, and a reflected optical pulse Sin is received, after a response time T required for the distance to the measuring object. Intensity Sin of the reflected optical pulse is attenuated, corresponding to the distance and is amplified by an anti-fiber amplifier. The light output of pumping light LDp from an excitation light source increases linearly, following the lapse of time after starting at a rising time of the optical pulse LDs, becomes zero, immediately after the lapse of a light-receiving period, and maintains zero during the period of a quiescent time Tr. An optical amplification factor Gain of an optical fiber amplifier is increased, corresponding to elapse of time from emission of the optical pulse LDs, by exciting the optical fiber amplifier by the sawtooth-shaped pumping light LDp. Thus, the intensity Sout of the amplified reflected optical pulse becomes a constant value which dies not depend on the distance to the measuring object, and thereby the distance can be measured with higher accuracy. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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