Research/Three-Dimensional Image Display using Laser Breakdown Plasma in Water

Optics for Three-dimensional Bitmap Image Projection†

We used a high-power YAG laser to ignite a spatial sequence of plasma dots in water and use it to construct a three dimensional bitmap image. Electromagnetic galvanometric mirrors (X and Y) are used to spatially scan the YAG laser beam, and a translating lens driven by a longitudinal shutter is used to control the depth position of focal point in liquid. City tap water was found to be a good material for igniting laser breakdown plasma.

Maximum pulse speed of the YAG laser was 5 kHz and the frame rate of the scanner is limited by the bulky galvanometric scanners, and hence the maximum number of bitmap dots is limited to be a few tens to a hundred per frame. This could be improved by using a lighter optical scanner (by MEMS) and using faster pulse YAG laser. Further study should be made on material that could be ignited with lower threshold YAG power.

By seeing the plasma in water through a color-changing LCD (liquid crystal display), the plasma bit array can be colored in red, green, and blue. We are also working on a flexible version of such color-changing filter by using the plastic MEMS technology.

final4.wmv

final4 - Mac.mov

本プロジェクトは、２００５年４月から２００８年３月にかけて、財団法人神奈川科学技術アカデミーの３年間プロジェクトとして運営致しました。

This work has been performed within the framework of the Optomechatronics Project of Kanagawa Academy of Science and Technology (KAST) from April 2005 to March 2008.