Simultaneous Multi-Bit Recording in Fused Silica for Permanent Storage

In recent years, optical discs and hard disc drives have been widely used as storage media. However, the lifetime of recorded data in these media is about 100 years. On the other hand, a permanent storage system that can store data for more than 1,000 years is strongly required, especially for historically valuable data. One candidate system for permanent storage is a system using fused silica, which is thermally and chemically stable. In this paper, we reported simultaneous multi-bit recording in fused silica with a femtosecond laser and a spatial light modulator. The recording quality was evaluated using signal-to-noise ratio with an optical microscope. We recorded a four-layer sample with a dot pitch of 2.8 µm and obtained a signal-to-noise ratio greater than 15 dB. Furthermore, we confirmed that the sample had good thermal resistance at 1,000 °C for 120 min, which indicates a lifetime of over 319 million years.

[1]  Andy Steinmann,et al.  Double waveguide couplers produced by simultaneous femtosecond writing. , 2009, Optics express.

[2]  Masaaki Sakakura,et al.  Parallel Drawing of Multiple Bent Optical Waveguides Using a Spatial Light Modulator , 2009 .

[3]  Masaaki Sakakura,et al.  Fabrication of three-dimensional 1 x 4 splitter waveguides inside a glass substrate with spatially phase modulated laser beam. , 2010, Optics express.

[4]  K. Miura,et al.  Writing waveguides in glass with a femtosecond laser. , 1996, Optics letters.

[5]  Saulius Juodkazis,et al.  Three-Dimensional Optical Data Storage in Vitreous Silica , 1998 .

[6]  J. P. Callan,et al.  Three-dimensional optical storage inside transparent materials. , 1996, Optics letters.

[7]  A. Streltsov,et al.  Fabrication and analysis of a directional coupler written in glass by nanojoule femtosecond laser pulses. , 2001, Optics letters.

[8]  Saulius Juodkazis,et al.  Crosstalk in Photoluminescence Readout of Three-Dimensional Memory in Vitreous Silica by One- and Two-Photon Excitation , 2000 .

[9]  S. Nolte,et al.  Femtosecond waveguide writing: a new avenue to three-dimensional integrated optics , 2003 .

[10]  J G Fujimoto,et al.  Photonic device fabrication in glass by use of nonlinear materials processing with a femtosecond laser oscillator. , 2001, Optics letters.

[11]  E Audouard,et al.  Dynamic ultrafast laser spatial tailoring for parallel micromachining of photonic devices in transparent materials. , 2009, Optics express.

[12]  Tsuneo Mitsuyu,et al.  Photowritten optical waveguides in various glasses with ultrashort pulse laser , 1997 .

[13]  Takao Watanabe,et al.  A digital-data-preservation system featuring LED-light computer tomography , 2009, IEICE Electron. Express.

[14]  Saulius Juodkazis,et al.  Two-photon readout of three-dimensional memory in silica , 2000 .

[15]  Masaaki Sakakura,et al.  Improved phase hologram design for generating symmetric light spots and its application for laser writing of waveguides. , 2011, Optics letters.

[16]  E. Mazur,et al.  Ultrafast-laser driven micro-explosions in transparent materials , 1997 .

[17]  Kazuyoshi Itoh,et al.  Motion of bubble in solid by femtosecond laser pulses. , 2002, Optics express.

[18]  J. Nishii,et al.  In situ observation of photoinduced refractive-index changes in filaments formed in glasses by femtosecond laser pulses. , 2001, Optics letters.

[19]  E. Mazur,et al.  Micromachining bulk glass by use of femtosecond laser pulses with nanojoule energy. , 2001, Optics letters.

[20]  Kazuyuki Hirao,et al.  Three-Dimensional Optical Memory Using Glasses as a Recording Medium through a Multi-Photon Absorption Process , 1998 .

[21]  Daniel Day,et al.  Formation of voids in a doped polymethylmethacrylate polymer , 2002 .

[22]  Y. Shimotsuma,et al.  Self-organized nanogratings in glass irradiated by ultrashort light pulses. , 2003, Physical review letters.

[23]  Peter R Herman,et al.  Broadband directional couplers fabricated in bulk glass with high repetition rate femtosecond laser pulses. , 2008, Optics express.

[24]  Saulius Juodkazis,et al.  Transmission and photoluminescence images of three-dimensional memory in vitreous silica , 1999 .

[25]  Masaaki Sakakura,et al.  Ultrafast Manipulation of Self‐Assembled Form Birefringence in Glass , 2010, Advanced materials.

[26]  E Audouard,et al.  Ultrafast laser photoinscription of polarization sensitive devices in bulk silica glass. , 2009, Optics express.