Image quality improvement using speckle method in in-line digital holography by means of multi-mode fiber

We present image quality improvement using speckle method in an in-line digital holography by means of a multi-mode fiber. In the proposed method, we use the speckle field emitted from the multi-mode fiber as both a reference wave and the wavefront illuminating an object. The interference pattern of a speckled reference wave and an object wave is recorded as digital holograms on a CCD camera. To capture multiple holograms in speckle method, speckle fields are changed by vibrating the multi-mode fiber using a vibrator. This method has the advantages in that an optical system becomes simpler due to the use of an optical fiber and speckle method can be readily performed by using speckle fields emitted from the multi-mode fiber with a vibrator.