Digital holographic data storage in a high-performance photorefractive polymer composite

Area of Science:

• Materials Science
• Optics
• Information Storage

Background:

• Holographic data storage offers high-density information retrieval.
• Polymeric photorefractive composites are key materials for holographic applications.
• Efficient and rapid recording of digital holograms is crucial for practical use.

Purpose of the Study:

• To investigate the holographic storage capabilities of a novel polymeric photorefractive composite.
• To evaluate the effect of 2,4,7-trinitro-9-fluorenone (TNF) concentration on recording speed and optical quality.
• To determine the figure of merit for holographic storage in the developed material.

Main Methods:

• Fabrication of a 130-mum thick composite using poly(N-vinyl carbazole) matrix, an organic chromophore, and varying concentrations of 2,4,7-trinitro-9-fluorenone (TNF).
• Holographic recording of a 256 x 256 pixel binary data array using a degenerate four-wave mixing arrangement.
• Measurement of refractive-index modulation, recording speed, and figure of merit (M#).

Main Results:

• High TNF concentration (up to 11.2 wt. %) enabled rapid digital hologram recording times of 2 seconds.
• The refractive-index modulation achieved was 10⁻³, with a recording speed of 200 ms.
• A figure of merit (M#) of 0.017 was measured, with an estimated potential of 0.18 in an optimized geometry.

Conclusions:

• The developed polymeric photorefractive composite demonstrates efficient and fast holographic data storage.
• Increased TNF concentration significantly reduces hologram recording time without compromising optical quality.
• The material shows potential for future high-performance holographic storage systems.