papers & manuals

hardware
drives

software
drivers

Description

Introduced by Constellation 3D Inc. (C3D), Fluorescent Multi-Layer Disc holds up to 140 GB of data. This is currently (2001) 215 times greater than a CD-ROM (.65 GB) and 23 times greater than a DVD-ROM (6 GB).

FMD-ROM discs contain fluorescent materials embedded in the pits and grooves of all 10+ layers. When in contact with a laser, the fluorescent materials are stimulated to produce coherent and incoherent light; data is stored in the incoherent light.

Specifications

Because the technology isn't based on reflection, multiple layers are read at the same time.

With minor re-tooling, FMD-ROM discs are compatible with existing CD-ROM and DVD-ROM drives. Likewise, FMD-ROM drives are backward compatible, accepting CDs and DVDs.

The layers on a Reveo CLC disc reflect only a specific color.

The concept of multi-layer reflective optical discs has been proposed by Philips and IBM, and has been demonstrated up to several layers. In fact, DVD is an implementation of this concept with two layers.

However for many layers, the coherent nature of the probing laser beam causes interference, scatter and intra-layer cross talk - the combination of which results in a signal that is degraded to unacceptable levels. In addition, reflective multi-layer discs encountered considerable technological difficulties in manufacturing of media commensurate with the formidable requirements for optical quality. For these reasons research efforts into multi-layer reflective technologies have been abandoned.

The concept of multi-layer, fluorescent cards/discs (FMD/C) is a unique breakthrough, solving the problems of signal degradation associated with current reflective optical disc technologies of CD and DVD.

As with a CD or DVD, data on the FMD layers is encoded on a substrate in a series of geometrical features or volumetric marks. Each layer will have a capacity of 4.7 Gigabytes (as in the case of DVD).

With FMD/C technology, each storage layer is coated with a transparent fluorescent material rather than the reflective metallic layer of a CD or DVD. When the laser beam hits a mark on a layer, fluorescent light is emitted. This emitted light has a different wavelength from the incident laser light - slightly shifted towards the red end of the light spectrum - and is incoherent in nature, in contrast to the reflected coherent light in current optical devices. The emitted light is not affected by data marks, and therefore transverses adjacent layers undisturbed.

In the read out system of the drive, the laser light is filtered out, so that only the information-bearing fluorescent light is detected. This reduces the effect of stray light and interference. Theoretical studies, confirmed by experimental results, have shown that in conventional reflection systems the signal quality degrades rapidly with the number of layers. In fluorescent read-out systems, on the other hand, the signal quality degrades much more slowly with each additional layer. Research has shown that media containing up to a hundred layers are currently feasible, thereby increasing the potential capacity of a single card or disk to hundreds of Gigabytes. Use of blue lasers would increase the capacities to over 1 Terabyte.

Chronology

1999 first published in september

2001 first license given to Sony

2002 august C3D disappeared