Speckle reduction in near-field image of multimode fiber with a piezoelectric transducer

Woosung Ha, Sejin Lee, Kyunghwan Oh, Yongmin Jung, Jun Ki Kim

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


We propose and experimentally demonstrate an effective method to reduce near-field speckle noise at the output of a 50 μm graded index multimode fiber using a short cylindrical piezoelectric transducer (PZT) vibrating in the radial direction. The fiber was coiled as tightly as possible around the mandrel of the PZT and a periodic stretching effect was caused by the radial oscillations of the actuator. The output of the optical fiber using the He-Ne laser source was intensively observed by a CCD camera. By counting all the pixels corresponding to relative intensity graded into 256 levels in the selected area and by calculating standard deviation and mean value of the intensity, we could measure the speckle contrast and vibration effect quantitatively with reduction ratio of pixels and line profile of the illuminated region. It was clearly observed that the characteristics of the speckle pattern in the vibration-on state were significantly improved over that of the vibration-off state due to time-averaged smoothing.

Original languageEnglish
Pages (from-to)126-130
Number of pages5
JournalJournal of the Optical Society of Korea
Issue number3
Publication statusPublished - 2008

All Science Journal Classification (ASJC) codes

  • Atomic and Molecular Physics, and Optics


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