[21a-C205-1~6] CS.2 3.2 情報フォトニクス・画像工学（旧3.3）、4.4 Information Photonicsのコードシェア

▲ [21a-C205-3] Reduction of Periodic Noise Superimposed on the Surface Profile Obtained by Two-Wavelength FMCW-Digital Holography

〇Hikaru Hamada¹、Masayuki Yokota¹ (1.Shimane Univ.)

キーワード：FMCW-Digital Holography, Two-wavelength method, Parasitic interference

To conduct two-wavelength method, digital holography based on FMCW technique has been applied for wavelength-multiplexing in the time-frequency domain. The surface profile of the metallic plates having a known step-height was measured by using the proposed method. However, a periodic noise was superimposed on the measured profile, which degraded the accuracy of the measurements so far. In this study, to reduce the periodic noise, numerical calculations have been performed to investigate both the noise source and the noise-reduction method. As a result, the calculated results show that the origin of the noise is parasitic interference between the reference beam and the stray light from the optics of the experimental system. To avoid the interference noise, a method has been proposed to separate the beat frequency of the object wave from the noise frequency by adjusting the components of the system.