The Future Direction of Optical Data Storage Technologies and Challenges in the 21st Century Media-Tech 2006 Long Beach Long Beach, California October 10-11, 2006 < by > Richard G. Zech, Ph.D. Consultant & Expert Witness -Computer Storage & Photonics President & Managing Principal The ADVanced ENTerprises (ADVENT) Group Colorado Springs, CO 80906 (719) 633-4377 v [email protected] AAbbststrractact The advent of blue-laser (405nm) optical storage in the form of BD, HD DVD, holographic memories, and UDO would seem to signal the end of optical storage's technology life. But, in fact, the future of optical storage is still very bright. Once theoretical methods of capacity growth, such as multi- layer, multi-level, near-field, and holographic are ready to enter the product mainstream. The engineering challenges of these advanced recording methods on lasers, media, optical pickups, servos, and read/write channels will be significant, but achievable. One can confidently predict the future of optical storage will be 120-130mm disc media with capacities in the 100 GB to 1 TB range. October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 2 CConontetentnt Ø Part 1 -Introduction Ø Part 2 -Near term Futures Ø Part 3 -Bleeding Edge Futures Ø Part 4 -Some Enabling Components Ø Part 5 -Replication and Disc Manufacturing Ø Part 6 -The Bottom line Ø Part 7 -Appendices October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 3 PPaarrtt 11 Introduction Common Sense Ø Optical data storage is subject to Shannon’s channel capacity law: C = Nxlog2(1+S/N), where N is a function of l and NA and S/N of media quality. Ø In English, you can’t put 10 lbs of polycarbonate in a 1 lb polyethylene sack. Ø I can’t, and neither can anyone else. October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 5 I started research in optical storage at an early age. October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 6 October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 7 The ODS Product Technology Cycle October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 8 Optical Storage's Moore's Law source: Unaxis October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 9 October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 10 ClClaassssiicacall OOppttiicacall SSttoorraaggee -- II IIss tthhee eendnd ooff tthhee ttecechnologhnologyy linlinee inin ssighight?t? Ø Laser diode (LD) wavelengths (l) have reached the end of the visible spectrum at 405nm. Ø Conventional objective lens have reached the limit of usable numerical apertures (NAs). Ø Spot size is a function of l/NA; shorter ls and bigger NAs yield smaller spot diameters and higher areal densities. Ø The technology life appears ended - but wait! This is only true for linear thinking and design. October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 11 ClClaassssiicacall OOppttiicacall SSttoorraaggee -- 22 IIss tthhee eendnd ooff tthhee ttecechnologhnologyy linlinee inin ssighight?t? Ø For l fixed at 405nm, classical optical storage can increase capacity in several ways, alone or in combination. Ø Architecture Examples: – Multilayer Discs (MLD); 2-N surfaces. – MultiLevel Recording (MLR); replicated, phase change. – Near-Field Recording (NFR); read-only and write/read. – Fluorescent Multilayer Disc (FMD); read and record. Ø Attractive Combinations: – MLD + MLR (25-50 GB/surface x 2.5 ML gain x N surfaces or 250-500 GB/120mm disc). – NFR + MLR + MLD (50-200 GB/surface x 2.5 ML gain x 1-2 surfaces or 125 GB -1 TB/120mm disc). October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 12 October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 13 PPaarrtt 22 Near Term Futures Today + 5 years Technologies Ø Multilayer Recording – Increases capacity without requiring a corresponding increase inareal density. – 8-layer discs with 200 GB capacity demonstrated by TDK and Philipsusing Blu-ray layers. – Increases optical media manufacturing and replication complexitysignificantly. Ø UDO – 30 GB cartridges shipping today; 60 GB cartridges expected in 2007. – A blue-laser concept, but not Blu-ray (computer application oriented). – Roadmap capacity to 120 GB/cartridge. Ø Near-field Recording (NFR) – Multiplies effective NA. – Maximizes areal density and surface capacity. – Trades MLD disc manufacturing complexity for optical head-disc interface complexity. Ø MultiLevel Recording (MLR) – Provides a practical 2.5x multiplier per layer (8 levels). – Can be implemented with a single DSP; not too expensive. – Works with any optical storage recording technology. Ø 3-D Holographic Memories (Holomems) -Disc Architectures – Deliverable products by end of 2006 after 43 years of R&D. – Mainly professional AV storage, archiving, some general applications. – Only two real players: InPhase Technologies & Optware (Japan). Ø Fluorescent Multilayer Disc (FMD) – Great concept (discrete layer 3-D storage), but some inherent problems. – Need some heavyweight funding for product development. – Excellent HDTV playback demonstrated for 6-layer disc (red laser). October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 15 a) Multilayer Disc October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 16 BluBlu--rraayy DiDiscsc SSttaannddaarrdd RReeffeerreenncece Source: Philips October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 17 BBlulu--rraayy DDiiscsc RRooaaddmmapap Source: TDK October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 18 October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 19 b) UDO October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 20 UDOUDO -- TThhee OOththeerr BlBlueue--llaasseerr DiDiscsc Ø UDO = Ultra Density Optical (a Plasmon plc product) Ø Original design by Sony as successor to 5.25" MO. Ø Designed for computer applications (-R and -RW). Ø 30 GB cartridge media (2-sided phase change disc). Ø ANSI-standard 5.25" MO disc cartridge; jukebox ready. October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 21 Source: Plasmon plc October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 22 MSFB = mean (cartridge) swaps between failures. Source: Plasmon plc October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 23 c) Near-field Recording October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 24 October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 25 October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 26 NNearear--FFiieelldd RReeccoorrddiingng wwiitthh VSVSAALsLs Near-Field image of 60 nm Near Field marks written by near-field compared with Far-Field d d / 2 NEAR FIELD l VSAL = Very Small Aperture Laser Aperture Size Determines Resolution --Independent of Laser Wavelength. Exceptionally Small Spot Sizes -- 60nm spots (134Gb/in2) demonstrated in MO material. Beam of any shape demonstrated --Improves performance & design flexibility. (source: Lucent Technologies) October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 27 d) MultiLevel Technology Ø MultiLevel (ML) is not a product, but a performance-enhancement technology. Ø Fixed-size data cells support 8 reflection levels (variable areas) on a dye-polymer (-R) or phase change (-RW) recording layer. Yields about 2.5 bits per cell in practice (not the theoretical 3). Ø The enabler is a proprietary DSP chip (core IC) Ø ML-enhanced drives and media work for CD/DVD and Blue-laser formats. Should work for all disc formats. Ø 60GB per 120mm Blue Disc lab demonstrated (Calimetrics, now part of LSI Logic, and Philips research project). October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 28 e) Holomems October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 29 HHoollooggrraapphhiicc MMeemmoorriieses ((HHoollomomeemms)s) October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 30 October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 31 HHoollooggrraapphhiicc MMeemmoorriieses -- HHiisstotoryry Ø Original concept by P.J. van Heerden (Polaroid) in 1963, based on D. Gabor’s “wavefront reconstruction”(holography). Ø Generally agreed to be impractical by 1975. Ø Over 50 companies worldwide have invested in and abandoned the technology (1965-2005). Ø The early 1990s saw a resurgence in interest; for example, DARPA’s HDSS/PRISM program helped to greatly advanced the art. Ø The “no moving parts”(random access) BORAM model has been abandoned in favor of the (direct access) optical disc model. Ø Advances in lasers, storage media, photodetector arrays (PDAs), spatial light modulators (SLMs), hologram stacking methods, data coding, and signal processing have made 300GB 130mm discs feasible today. Ø Today’s leading companies are InPhase Technologies and Optware (Japan). Ø After more than 40 years of R&D, holographic memories (holomems)appear on the threshold of commercial viability for a limited set of applications; for example, general archiving and digital video storage. Holomems are not suitable for consumer electronics applications today. However, they can effectively support the creation and delivery processes. October 10, 2006 The ADVanced ENTerprises (ADVENT) Group 32 PrProoss aanndd CCoonnss ooff HHoolloommeemsms Pros Ø Parallel write/read of large data pages (1024 x 1024 pixels common). Ø 3D stacking of holograms in a common volume (increases 2D areal storage density by a factor of 1,000x, or more). Ø Simple read mechanisms, which reconstruct each data page independently (ideally, with no crosstalk). Cons Ø Complex system designs. Ø Demanding storage media requirements. Ø Lack of infrastructure (photonic components challenging; optical communications applications have driven lower pricing, volume, and reliability). Ø Expensive hardware ($15,000 drives)