PROBLEM TO BE SOLVED: To provide an optical interference measurement device that is capable of accurately obtaining internal information of an object and is suitable for application or the like for accurately measuring a relative position between a specific object and the object, and to provide a drill control method utilizing an optical interference measurement.SOLUTION: An optical interference measurement device includes: a low coherence light source 18 for outputting an irradiation light ε an optical fiber coupler 26 for dividing the irradiation light ε into a reference light α and a measurement light β1 and outputting both of them and a reference mirror part 20 for receiving the reference light α and reflecting it. The optical fiber coupler 26 multiplexes an object light β2 which is a reflection light from a specific part having received the measurement light β1 and the reference light α reflected by the reference mirror part 20, and includes an interference optical analysis part for detecting and analyzing an interference light γ between the reference light α multiplexed by the optical fiber coupler 26 and the object light β2. The reference mirror 20 includes a plurality of staircase mirrors 34 formed with a plurality of reflection surfaces 32(1) to 32(4) in parallel with each other and having a level difference and a shutter 36 for allowing the reference light α to reflect by selecting any one of the reflection surfaces 32(1) to 32(4).COPYRIGHT: (C)2015,JPO&INPIT【課題】対象物の内部情報を高精度に取得することができ、特定物と対象物との相対位置を高精度に計測する用途等に好適な光干渉計測装置及び光干渉計測を利用したドリル制御方法を提供する。【解決手段】照射光εを出力する低コヒーレンスの光源18を備える。照射光εを分割して参照光α及び測定光β1を出力する光ファイバカプラ26と、参照光αを受けて反射させる参照ミラー部20を備える。光ファイバカプラ26は、測定光β1を受けた特定部分からの反射光である物体光β2と、参照ミラー部20が反射した参照光αとを合波する。光ファイバカプラ26で合波された参照光αと物体光β2との干渉光γを検出し解析する干渉光解析部を備える。参照ミラー部20は、互いに平行で段差を有する複数の反射面32(1)~32(4)が形成された複数段ミラー34と、反射面32(1)~32(4)の中の何れか1つを選択して参照光αの反射を可能にするシャッタ36とを有する。【選択図】図1
