FIELD: physics.
SUBSTANCE: apparatus has two switching units, the first switching unit 17 of which switches between a first state in which a detecting unit 16 is configured to detect a combined beam 15, and a second state in which the detecting unit is configured to detect a reference beam 14. The second switching unit switches between the first state and a third state in which the detecting unit is configured to detect a returning beam 12. A interferometric information acquiring unit 19 acquires interferometric information on the returning beam 12 and the reference beam 14 using the combined beam 15 detected by the detecting unit 16 in the first state, the reference beam 14 detected in the second state, and the returning beam 12 detected by the detecting unit in the third state.
EFFECT: invention enables to remove noise caused by the autocorrelation component of returning light to obtain a high-resolution tomographic image.
12 cl, 8 dwg
