Abstract: In a position control device having a disturbance suppression function, loop gain is calibrated without stopping disturbance suppression control. The position control device has, for disturbance suppression control, a feedback controller for changing the loop characteristic, a table for storing a target gain according to a disturbance frequency, and a gain calibration section for calibrating open loop gain. The gain is calibrated using a target gain in the table according to the change of the loop characteristic of the feedback controller. Open loop gain can be calibrated without interrupting the disturbance suppression control, so the open loop gain can be accurately calibrated without being affected by disturbance, and accurate position control is possible.

Abstract: An optical coherence tomography apparatus constructs a tomographic image of a measurement object on the basis of a spectral characteristic obtained by spectrally dividing interference light, which combines signal light composed of the measurement light reflected by the measurement object and reference light, using an optical demultiplexer.