Mikio Sugiki

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

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.

Line Segment Hologram Writer Using Single-Mode Blue Laser and One-Dimensional Spatial Light Modulator

We have developed a holographic writer using a one-dimensional spatial light modulator and a single-mode blue laser. This writer has the potential of achieving a 5 µm pitch phase correlation multiplexing.

Line segment hologram writer utilizing 1D spatial light modulator

We developed one dimensional data pattern hologram writer using GLV device as a spatial light modulator. The following advantages were expected: easier pixel matching, simpler signal processing, low height drive and high transfer rate. 171 angular multiplex recording holograms on a 1mm thickness polymer media, corresponding to 6.22 pixels/μm2 in density were demonstrated. With a Bit Error Rate (BER) of less than 2 x 10-4, 101 multiplexing holograms were successfully stored. Then, considerable error factors were discussed and solutions were given for higher multiplex recording.

Optical System Designed for Coaxial Holographic Recording on Continuously Rotating Disc

This study introduces the specified objective lens and the new image position servo system to the coaxial holographic recording system. The validity of these technologies is verified analytically and experimentally

Development of a Coaxial type Holographic Disc Data Storage Evaluation System, Capable of 500-fps-Consecutive Writing and Reading

A coaxial type holographic data storage evaluation system, capable of 500-fps-consecutive writing and reading, has been developed, whose light source is a semiconductor blue laser diode. This is realized by an image-stabilizing technique.

A write-once video disc recording system using time-division multiplexing

A write-once optical video disc system for recording pictures with digital audio is developed. Signals are processed by time-division multiplexing with an analog component, which produces a high-quality picture. Alloy phase-change is used as the recording mechanism. This yields a record whose storage life more than 100 years. >

Optical pickup for high-speed writer using multibeam laser diode

We have developed an optical pick up with multi beam laser diode (LD). Multi beam LD has three emitters and individual emitter can control independently. Primary experiment for parallel recording has done and acceptable results for Power Margin, Tilt Margin, Defocus smargin and Detrack margin have measured. After than, possibility of double speed recording has confirmed by dual beam recording method.