DETECTION DEVICE AND DETECTION METHOD

To provide a detection device and a detection method capable of detecting a deviation amount of an actual frequency difference with respect to a requested value of a frequency difference even in a case where the frequency difference which is a difference between a frequency of continuous light of a first laser and a frequency of continuous light of a second laser, is equal to or greater than a predetermined value.SOLUTION: A detection device comprises: a sideband generator which generates a first optical sideband having a plurality of optical carriers in a different frequency for which a frequency based on a third frequency is multiplied, using a first continuous light, in a case where a requested value of a difference between a first frequency of the first continuous light and a second frequency of second continuous light is a natural number multiple of a third frequency; a wave detector which executes wave detection processing using an optical carrier which is selected from the first optical sideband as an optical carrier in a frequency close to the second frequency, and the second continuous light; and a deviation derivation unit which derives a positive/negative deviation amount of the difference with respect to the requested value on the basis of a result of the wave detection processing.SELECTED DRAWING: Figure 1 【課題】第１レーザの連続光の周波数と第２レーザの連続光の周波数との差である周波数差が所定値以上に大きい場合でも、周波数差の要求値に対する実際の周波数差のずれ量を検出することが可能である検出装置及び検出方法を提供する。【解決手段】検出装置は、第１連続光の第１周波数と第２連続光の第２周波数との差の要求値が第３周波数の自然数倍である場合に、第３周波数に基づく周波数が逓倍された異なる周波数の複数の光キャリアを有する第１光サイドバンドを、第１連続光を用いて生成するサイドバンド発生器と、第２周波数に近い周波数の光キャリアとして第１光サイドバンドから選択された光キャリアと第２連続光とを用いて、検波処理を実行する検波器と、検波処理の結果に基づいて、要求値に対する差の正負のずれ量を導出するずれ導出部とを備える。【選択図】図１