Persistent Hole Burning and Holography in Anthraquinone Derivatives

We have reported persistent spectral hole burning (PHB) in anthraquinone derivatives. 1-3) Hole burning spectroscopy desires high resolution to detect narrow and shallow holes. Laser induced grating (Holography) technique is very effective for the investigation of a shallow hole, because it enables to detect a small signal without a large background. 4-6) In addition, we can achieve many holographic applications: 3D image storage and reconstruction, holographic memory, holographic computing, etc. However, we should note that hole signal represents a diffraction efficiency in holographic detection, not the absorption spectrum. Consequently, material characteristics, hole width, depth, area, Debye-Waller factor, etc., are not directly obtainable using holographic detection.