Improvement in Temperature Tolerance of Holographic Data Storage Using Wavelength Tunable Laser

Abstract

In this paper, we report a new method of increasing the temperature tolerance of holographic recording media using a wavelength tunable laser. Of all holographic media, photopolymer media are particularly sensitive to temperature, thus some methods are required to maintain a low bit-error ratio (BER) as temperature changes. We demonstrate here how to maintain a high signal-to-noise ratio (SNR) as temperature changes using a wavelength tunable blue external cavity laser diode (ECLD) currently under development. For comparison, we analyze the temperature tolerance by a angle-tuning method and a wavelength-tuning method. We have focused that a hybrid of wavelength-tuning and angle-tuning method, we can read out the full of the image at 60°C, which is +30°C above the recording temperature. Moreover, we propose a recording method that allows the wavelength to be adjusted to the temperature changes. By adjusting the wavelength linearly to the temperature changes during recording, we can read out the holograms recorded at different temperatures using the wavelength corresponding to the readout temperature.