World's first holographic disc drive unveiled

By Steve Malone

Posted on 5 Jan 2005 at 12:50

Colorado-based start up InPhase Technologies has announced a prototype of what it says is the world's first holographic disc drive. The company says that it intends to develop a family of WORM drives under the name 'Tapestry' with capacities ranging from 200Gb up to a whopping 1.6Tbytes.

Holographic storage has been something of a holy grail amongst storage manufacturers for some years. Instead of storing data on the surface of a disc, a holographic drive will store data through the thickness of the drive itself. It is created by an interference pattern created by two light beams being fixed within the storage medium itself. Afterwards, one beam shining through the medium can recreate the pattern and read data back.

The key to creating holographic storage lies within the light source and the medium itself. The storage material used to construct the disc is based a 1.5mm thick photopolymer material. The 1.5 mm thick recording material is sandwiched between a pair of 130 mm diameter transmissive plastic disk substrates. The whole unit is held inside a new cartridge developed with Hitachi Maxell to protect the light-sensitive recording material from corruption. Maxell is also said to be developing the commercial media manufacturing processes.

The other key component is a 407nm blue laser to provide the necessary wavelength required for high capacity holographic storage, which has only recently become commercially affordable. Finally, collection of the data is via a CMOS active pixel sensor arrays.

Inphase says that the prototype drive includes all drive subsystems such as the auto load/unload mechanics, servo system, holographic read/write head, data channel and electronics.

The company claims that the prototype can fit more than one million bits of data into a single page, which is recorded with a single flash of the 407 nm laser beam. Multiple pages of data, referred to as a book, are recorded in one spot on the disk providing approximately 12MB of data in a single book location.