In this series, we will explore the next generation storage media that are just around the corner and will bring enormous storage capacity to everyday user. A 1 TB HDD isn’t enough and is slow, the DVD can’t bring HD and flash drives provide meager storage capacity at large costs. So, what are the solutions? This week we bring you the latest is optical disc storage.
We’ve all seen it. The bitter fight around the Blu-ray and HD DVD and we all know who won the race. But, are we ready for the next generation? Laser based optical storage media has been around forever. If somebody told you that a laser based storage medium is revolutionary, then he is wrong. CDs, DVDs and Blu-Rays all utilize lasers of different wavelengths. The smaller the wavelength of the laser, the larger the storage capacity.
The next generation of devices will utilize mutliple layers to maximize storage capacity. But it isn’t this simple. Making multiple layers possible is a very very tough job.
TeraDisc
Developed by a company called Mempile, the TeraDisc as the name says, promises TeraBytes of storage capacity with a DVD size disc. It is implemented with high cost materials to create an optical media with unique light-sensitive properties. The science behind all the storage is something called a two photon absorption. Currently the disc can store up to 500GB in a transparent disc, the thickness of a DVD, but the company is aiming for 200 layers of data, with 5GB on each layer, thus giving a terabyte of storage.
Holographic Versatile Disc (HVD)
Developed by a consortium of companies called the HVD Alliance, it promises a mind boggling 3.9 TB of storage. The technique that makes it possible is called collinear holography, in which two lasers are used as a single laser (red and blue-green). The blue-green laser is used to read data from the top of the disc and the red laser is used to read servo information from a CD layer near the bottom. That is complicated stuff but let me make it simple.
The transfer rate it promises is 1 Gbit/s compared to a meagre 48 Mbit/s for Blu Ray discs. Current optical storage media save one bit per pulse while the HVD promises around 60,000 bits per pulse. The 3.9 TB is of course theoretical only, but current prototypes are utilizing 500GB of storage.
A standard SD ard looking like Holographic versatile Card (HVC) has also been prototyped.
Tapestry 300r
Developed by a company called Inphase Technologies, it also uses holographic storage. The tapestry 300r is the world’s first commercial holographic storage drive. It has a storage capacity of 200GB and a 20Mb/s read/write rate.
The future models promise further more storage capacity, with the tapestry 800r and tapestry 1600r promising 800GB and 1.6TB of storage. The data rate is expected to be 120MB/s. The company is unique as they are the only ones who have delivered what they promised, even though there were huge delays.
Fluorescent Multilayer Disc (FMD)
It was one of the very first prototype 3D optical storage media to surface. The idea behind the disc is that traditional reflective surfaces prevent multiple layers because of diffraction. This however, will allow layers and layers of storage with fluorescent material instead of reflecting material. It has been developed by a company called Constellation 3D (C3D). It is similar in size and appearance to regular CD-ROMs and DVDs. The promise of storage is around 140 GB of data, far greater than even a Blu Ray disc. The company also promises cheap production. They also claim that the current wavelength of 650 Am should be sufficient enough to store up to a Terabyte of data. Now that’s something.
The company was shut down after it was revealed that their prototype was a hoax and they faked everything. A new company called D Data Inc. bought the technology and aims to release its Digital Multi-player Disk (DMD) based on the same technology.
Protein Coated Disc (PCD)
Proposed and currently being developed by Professor Venkatesan Renugopalakrishnan, PCD would greatly increase storage over Holographic Versatile Disc(HVD) optical disc systems. It involves coating an ordinary DVD with a special light-sensitive protein produced from the genetic alteration of a microbe. In theory it promises storage up to 50TB. Research with NEC in 2006 prmoised production in 24 months, but since then the idea has been facing problems.
The technology uses the photosynthetic pigment bacteriorhodopsin which is created from bacteria. The light-activated proteins are called bacteriorhodopsin which are found in the membrane of a salt marsh microbe. When exposed to sunlight, they temporarily convert to a series of intermediate molecules. This property allows the proteins to act as individual bits in a binary system.
