Friday, July 21, 2006

Holographic Data Storage—the Next Generation in Storage

The concept for holographic data storage was first proposed by Pieter van Heerde at Polaroid but key researchers and companies are bringing this emerging technology closer to commercial application. The concept behind holographic data storage is based on a signal beam that goes through a spatial light modulator (capturing an image of binary zeros and ones) that then intersects a reference beam and stores the resulting image on a recording medium. Using a charged-couple device and the same reference beam (at the same angle and wavelength), one recovers the signal beam image. By varying the wavelength and the angle one can store additional images on the same medium thus increasing the density of the storage system. Since one need only change the angle or wavelength of the reference beam, data storage and access is fast as well.

This technology brings two benefits to the storage problem. First, a “page” of data is captured and stored at a time rather than a bit of data. This speeds up the process of data storage and retrieval. Second, since data is retrieved using unique wavelengths, more data can be stored by “stacking” one image on top of another in a three dimensional fashion.

Some sites predict desktop systems to have storage capacities of 1 terabyte and transfer rates of 1 gigabyte.

Key companies to watch start with the leader in this field called InPhase Technologies. Based in Colorado they were spun out of Lucent in 2000. They offer boxes that can store up to 35 hours worth of broadcast video at 19 mbps. Challenges in bringing holographic storage to the market include finding a suitable material that can hold stackable images. Bayer Materials Sciences helped solve this problem with a unique photopolymer material. Also, the cost of lasers had to come down. The commoditization of lasers in CD and DVD players helped here. This whitepaper provides more background detail. They offer a cool technology demo of their product here.

Virtual Instrumentation applications include Daewoo who uses LabVIEW and Compact Reconfigurable I/O devices to drive the electro-optical motion control system including a linear motor, a stepper motor, a galvo mirror, and a CMOS camera.

JPL used LabVIEW to develop a custom phase-array profile driver which controls a unique beam steering mechanism for reading and storing data in a holographic memory system.

What is beyond holographic-based storage? Protein-based storage. Scientists in India have found a protein that reacts to light turning data into information which can hold information for several years.

Best regards,
Hall T.