Digital Data Etched into the Glass Disc

Archive and forget



There is wide concern about the non-reliability of Archiving Media typically available on the market today; whether physical or virtual, the performance of products seldom lives up to their marketing announcements

EONDisc4What are the choices proposed today?

  • We know the too-short History of IT is full of examples of lost formats and players that are difficult to find.
  • The right choice for an archiving system will be oriented through a solution providing a perennial read back.
  • This means the Format must correspond to a de facto norm.


MagnetbänderMagnetic Tapes

  • Analog or Digital, even though they are well known and familiar ..they are now from the Past!
  • Quite good Capacity, but physically rather fragile, and they get much worse over time.
  • The Players are more and more difficult to find on the market
  • Who’s not seen a scrambled tape?!


FestplatteHard disks

  • More and more convenient, and with high performance, able to store enormous capacity at a relatively low cost. Can be configured in a robust way by mounting in RAID or Mirror
  • Today’s configurations are using a Priority Format Basis (NTFS, HFS+ ) which doesn't’t guarantee a long life in the marketplace.
  • All Hard Disc platters spin at 10 000 to 15 000 rpm, with a microhead flying over it at less than 0.1mm from the surface, and so a piece of dust or a small defect and…
  • You have no warning of a Crash!!

Optical Discs

  • Optische DatenträgerVery convenient for a quick Back-Up, & easy to use, they are (because of their Format) the only guarantee of a safe Play Back in the future (CD is already 30 years old).
  • Current media is unfortunately becoming less and less reliable, because of competition (Quality-price war). Also, the most modern formats operate close to the optical limits, and so are more fragile, and require more careful manufacture. CD> DVD>… BD
  • Recordable Discs are much more susceptible to corrosion because of the materials used.
  • They are not damaged by laser re-reading and can be read an infinite number of times, but may be affected by Time..


Disc DamagesThe components of the optical disc

  • The Polycarbonate used in Disc Replication is Fragile
  • Sensitive to scratches, discs slowly increase in tilt, and become increasingly opaque over time. For the Blue Ray, the tilt is very important and the Cover-Layer is very Thin. The Hard Coat is only here to give confidence because the hard coat is kept to a minimum thickness to prevent it affecting disc deviation
  • Sensitivity to corrosion
  • Sensitivity to humidity, temperature
  • All these media need Controlled Atmospheres, Tests Control procedures, Writing Strategies and from time to time multiple copies to rewrite…- from which the cost is often forgotten! -


RecordableRecordable Discs

  • The Dye (Organic) has been chosen for its Sensitivity with the Light and Temperature: so Paradoxical for Archiving!
  • One can propose Noble metals as Gold for Reflection Layers, This will give Confidence, but will not change the LifeTime of the “Sandwich”!


Century Disc principlesThe Glass-Disc

  • Patented technology since 1988
  • Available in CD format, and DVD single (4.7Gb) or double-sided (9Gb)
    In the future it could be made with Blu-Ray (23Gb) and double-sided (46Gb)

CD Format for Audio and DVD for Archive

  • Audio on Glass Disc CD because:
    Very flat, scratch-resistant, gives excellent Jitter (13ns)
  • Archive on glass DVD because:
    Rigid support, scratch-resistant, Platinum as Reflector Layer, and Hard-baked (150 deg) Epoxy-Acrylate bond. Data surface is embedded.
  • Always possible to recover data if there are any problem
    .(HNO3 dipping then metallized again)



BDCenturyHD Glass Disc

  • Same technology as the CD and DVD, with RIE Etching of the Support Disc.
  • 1.0mm substrate for double-sided (1.1mm Single Side)
    The substrate may not be glass.




We need to Sort our Data to Archiving

  • Instead of choosing unstable and disposable products or archiving everything and in effect nothing…
  • Let’s Sort the Data we want to Archive
  • Let’s become Friendly to our Environment
  • Simply choose a Stable and Reliable Product: The genuine and only


Glass DVD auf dem MarsConclusion

  • The company is presently investing in automated CD and DVD Rom SDG-Masterglass Disc manufacture
    The BDRom SDG-Masterglass is still an ongoing Project , but will cost more and will need a lot of highly skilled people.
  • The “SDG-Masterglass Disc”TM is the only Product “Archive and Forget”

Reference Customers:Lockheed Martin, NASA, Thomson / Thalesgroup, Japan Aerospace Exploration Agency JAXA, Bibliothéque nationale de France, EDF, France Telecom, Musée Rodin, Avantis


The SDG-Masterglass Technology

The SDG-Masterglass-Disc

The Top Quality as only Requirement




  • Description of the SDG-Masterglass-Disc Technology
  • The multiple advantages of the SDG-Masterglass-Disc
  • The multiple applications of the SDG-Masterglass-Disc
  • Why to choose an Audio SDG-Masterglass Disc?

References: BNF (Library of France), THOMSON, NASA...EDF, French Telecom,Avantis,...

Description of the SDG-Masterglass-Disc Technology

  • The informations are Plasma RF etched (RIE) in a tempered glass disc
  • the SDG-Masterglass-Disc: a Technology developed, patented, and commercialised by our company since 1988
  • Worldwide Exclusivity of this SDG-Masterglass-DiscTM

The Multiple Advantages of the SDG-Masterglass-Disc

  • Universality of the format (compatible on all players)
  • evaluative Support (CD>DVD>BD)
  • Professional Recording within an Incredible Quality
  • Mechanical, chemical et physical Resistance exceptional (shocks, scratches, vibrations, oxidation, humidity, UV, temperature, etc..)
  • Life Time much more Higher than classical CD
  • Ecologic and Economic (recopy, transfer or storage in special conditions unusable)
Glassmastering SDG-Masterglass Disc Technologie

The Multiple Applications of the SDG-Masterglass-Disc

  • Conservation of the Datas in severe environments
  • Metrology (Calibration Discs)
  • Long Term Archiving (legal archives, intellectual, cultural, medical, professional..)
  • Prestige Editions (Special Events, Luxuries)
  • ‘Audiophiles’ Editions Masters replacing CDR, DLT or other sensitive supports..

Why to choose the SDG-Masterglass Disc?

  • Handling resistant (scratches, sweat, shocks..)
  • Time Resistant (remains transparent and flat)
  • Lower Jitter and cleaner Pit Shape, better defined : Fidelity to the original Recording
  • Recording Flexibility (speed, track-pitch, , anti-Copy, ..)
  • Electrical Test supplied with each disc
  • Choice of decorations and reflector metals

Mechanical and Chemical Resistance

Comparison: SDG-Masterglass Disc CD/DVD
2 nm
30 nm
33 g
18 g
600 vickers
70 rockwell
maximum speed
36 000 rpm
4 000 rpm
number of falls 1m
350 000
8 10-6/*C
70 10-6/*C
test abrasion (Taber)
low temperature
-250 *C
-150 *C
high temperature
350 *C
80 *C
transformation point
550 *C
140 *C

Transparency, Flatness, Rigidity of this tempered glass are very important parameters for Life Time of the Datas

Time resistance

  • Ageing Tests: Arrhénius Law
  • Ageing Tests: 2 Test points chosen for an Extrapolation giving a certain Life Time..
  • Ageing Tests: ECMA Norm (ex: for CDR Average 30 years, but within the first years, one loose already some Discs, so Datas)
Disc Alterung Ambient Conditions
ECMA Norm Lebenserwartungs-Prognosen

Multi-backups and copies useless

Recording Fidelity

Classical Audio CD Century Audio CD

Lower Jitter (time clock pit jitter 13-15ns instead of 28-30ns for a Classical CD, 30-40ns for a CDR)





Form of etched pits (micro cups)



Bartholomée Statement


Recording Fidelity: Extract of the Glass Disc“SDG-Masterglass Disc and its Psycho-Acoustical Improvements” by Nicolas Bartholomée (famous french sound engineer)

  • "... By listening the glass disc it offers an absolute extraordinary transparency, emphasizes details, which does not appears by listening the normal disc.
  • The glass disc offers a nobility stamps heat immediately close the vinyl yet its sampling rate and resolution have not changed from the normal disc. Since I have the chance to hear all our masters in frequencies much higher sample set with unmatched resolutions (192kHz / 24 bit), listening to the glass disk is similar to tapping with its resolutions, with enjoyment of his unparalleled warmth.
  • The glass disk is a dynamic progression of a lot more subtle than those seen a listening to a normal disc and we are often forced to change the level of listening to a disc.
  • Even in the passages "Forte", the sound stills not aggressive for the ear, it remains fluid and graceful ... "
Wavelength 1 Wavelength 2


Recording Flexibility; Possible Customizing in mastering for every SDG-Masterglass-Disc:

  • Etched Unique Number
  • Anti-Copy Protection for every disc
  • Optimisation of many parameters as: Linear Velocity of the disc, Track-pitch,…
  • The Weight of the SDG-Masterglass Disc which is higher than a classical CD, is giving another dimension with handling and a smoother inertia for the reading stability

Electrical Tests

  • Electrical Test made for each Disc while 1/1000 for classical CDs, only statistical test
  • Visual Inspection for each Disc
  • Conformity Certificate supplied for every Disc

Choice of Decorations and Reflectors

Customised Decoration:

  • Serigraphy, Painting, Holography on epoxy, etc…
  • Protection and Reflector Materials :
    Aluminium, Brass-aluminium, Gold, Titanium, Chromium, Aluminium, Oxides.., Diamonds..
Long-term Archiving with SDG-Masterglass

Latest: long-term archiving on the glass discs etched with rectangular pits with no reflective layer

SDG-Masterglass-Archivar-EWith the directly into the tempered glass discs etched pits, it is possible to produce grown in the pits for the optimal sampling rectangular shape. Thus the benefits of technology come with sharp edges and high slope even better coverage. The laser light reaches the photodiode steeper slopes in the output signal.

The pit structure achieved with this technology is so clean that the player can read them without a reflective layer. Only the intensity of the laser needs to be readjusted, what most players are able to do for themselves. This is especially important for long-term archiving, which can be dispensed by the reflective layer and the protective lacquer. So we can just use the glass discs. Of course, the gold-coated "traditional version is" still to choose from.

SDG-Masterglass-Disc1This product is the first and only media in the world, who holds up forever, "as carved into the stone."All magnetic data storage systems such as hard disks and magnetic tapes can be compared to our solution only for temporary use will be considered suitable. Most only as a backup but not as long-term archiving.

Therefore, globally, many libraries, computer centres, state and provincial archives, radio and television stations on our glass discs especially happy. The vast archives of film, video, tape or microfilm records and archives can be replaced with an unlimited durable medium, certainly saved.

Gone are the days when you had to just copy everything over again, where a fire, water or electricity damage could destroy valuable documents. Our glass discs must be done only once and accessibility, network or broadcast capability and forgery are secured forever.

A medium is the passive, requires no maintenance, no electricity, or cooling, heat, cold, acid resistant and completely without costs.

Our long-term archiving products and services we have listed here at Products > List of services Long-Term Archiving

In this video you can see how the solar sail will open and where the glass-DVD is at the IKAROS probe

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JAXA IKAROS team with glass-DVD, Installation of glass-DVD on the spacecraft IKAROS, glass-DVD mounted on the spacecraft IKAROS




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Plasma etched Glass DVD with NASA Mars Expedition Phoenix with 250,000 names (including all Planetary Society Members) on Mars


Projects: Messages from Earth

Etched glass DVD with Phoenix with 250,000 names (including all Planetary Society Members) on the Mars


Reference Customers: Lockheed Martin, Thomson / Thalesgroup, NASA, Bibliothéque nationale de France, EDF, France Telecom, Musée Rodin, Avantis

Glass discs in Space

The Royal Way of archiving

The Japan Aerospace Exploration Agency, JAXA, sent on the 21th May 2010 the spacecraft IKAROS into space. This probe will use solar-photon sail.

On board he has is an etched glass DVD, which Planetary Society once again with a "Messages from representing the Earth." Just as in 2007 with the NASA Phoenix Mars expedition (see below).

In this video you can see how the solar sail will open and where the glass-DVD is at the IKAROS probe

This time, however, the glass DVD out there in free space, that is, in minus 270 degrees Celsius and all cosmic and solar radiations exposed and vulnerable. The disc was produced by our technology director Pascal André. This serves as a new reference for our unlimited durable SDG-Master Glass archiving technologies.

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JAXA IKAROS team with glass-DVD, Installation of glass-DVD on the spacecraft IKAROS, glass-DVD mounted on the spacecraft IKAROS


On the planet Mars


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Plasma etched Glass DVD with NASA Mars Expedition Phoenix with 250,000 names (including all Planetary Society Members) on Mars

The glass discs were used first in 1996 by NASA for the Mars Pathfinder, to store information on our terrestrial civilization at each target foreigners. The next NASA Mars Expedition Phoenix in 2007 also had Glass Disc here. The same process in the next Japanese space mission "IKAROS" and 'Akatsuki" in 2010 where the glass disc is used.

White Papers - Scientific Backgrounds

"White Papers" are usually structured like this:
1. 1. Detailed explanation of theories as interpreted according to personal taste, as the author of the original can not defend,
2. 2. Prior art, which suffers from the symptoms of the common theories
3. 3. Presentation of his own theory, with indication, why are all the other stupid,
4. 4. Evidence of his own theory, which because of their ignorance of others, devoted exclusively to combating certain symptoms,
5. 5. Bibliography in order to build a semblance of broad gauge and objectivity.

This method does not, we pursue! It carries many risks, come to wrong conclusions, interpret miss someone, possibly insulting, what do we really want to avoid.

Let us honour the representations are already known to specialists, we close the contacts short to eliminate subjectivity and fill any knowledge gaps. Please read the listed documents, you can clear up by sound scientific knowledge. Then, visiting on the Internet known institutes, companies and studios.

Take you questions directly to the scientists, designers, sound engineers or mastering engineer. You will be fascinated by the equipment arsenal of studio overwhelm almost limitless post-production facilities. Your information will be up to date, raised at the latest. Then, (below), we shall meet again!

SHANNON, C. E.: A Mathematical Theory of Communication, The Bell System Technical Journal, 1948

Hicks, Christofer: An Investigtation Into Time A Mikroscopic View of the Digital Audio Conversion Process, MTSU

Ken Pohlmann, Applied Digital Audio, Introductory Binary Mathematics, McGraw Hill, 1995

Hicks, Christofer: What is Dither? MTSU

Ryohei Kusunoki: Non-oversampling Digital filter-less DAC Concept, MJ magazine from Nov. 1996 through Dec. 1997

Mike J. Story, Duncan McLeod and Martin Reynolds: Resolution, Bits, SNR and Linearity, dCS Ltd, Great Chesterford, 1998

Mike J. Story: Timing Errors and Jitter, dCS Ltd, Great Chesterford, 1998

M.N.Harris, R. Kelly, D.A.McLeod, M.J.Story: Effects in High sample Rate Audio Material, Tonmeistertagung, Karlsruhe, 1998

Mike J. Story: A Suggested Explanation For (Some Of) The Audible Differences Between High Sample Rate And Conventional Sample Rate Audio Material, dCS Ltd, Great Chesterford, 1997

Bob Katz: Jitteressay. Digital Domain, 2002

Nika Aldrich, Dither Explained, Cadenza, 2002

Brandon M. Schexnayder: Reshaping Digital Audio: DSD Encoding as a Viable Alternative to PCM, MTSU, 2004

Dominik Blech, Min-Chi Yang: Diplomarbeit: Untersuchung zur auditiven Differenzierbarkeit digitaler Aufzeichnungsverfahren, Hochschule für Musik Detmold, 2004

DCA (Doug Carson & Associates), Eclipse Data Technologies, Datarius, Singulus Mastering, M2 Engineering

Audio Research Group, Stanley Lipschitz, John vanderkooy, Audio Engineering Society, Verband Deutscher Tonmeister, Audio Precision, dCS Ltd., Digidesign, Fraunhofer IIS, Fraunhofer IDMT

Emil Berliner Studios, Master Digital Corporation, Mastering Studio München, Galaxy Studios, Bauer Studios, Super Audio Mastering, AbbeyRoad Studios

David F. Cox, Kenneth V. Noren and Anindya Bhattacharya: Asymmetrical Subranging R2R DAC in ULP, Albuquerque, 2002

Bert van der Wolf, dCS: DXD=Digital Extreme Definition, 352,8kS/s

Mark Levinson: Re-vitalizing Audio Industry: Music and Health, 2004

1-bir Forum in Japan, 2004: Super DVD vs. PCM and Your Health - Shunjiro Ohba and Mark Levinson Demonstrates the Surprising Difference

And then you ask about something that does not depend on the development of theories and many years: over glitches. From zero to one we had to switch from the outset. They will lead some very entertaining conversations! Perhaps also on the health of many professionals. And now about Long Term archiving:

Longévité de l’information numérique / Les données que nous voulons garder vont-elles s’effacer ? Academie de Sciences & Academie de Technologie, Erich Spitz, Franck Laloë, Jean-Charles Hourcade, Paris, 2010, Invitation pdf, Conclusion et Recommandations pdf, Résumé pdf, Présentation des auteurs du rapport.pdf

André Streicher am 12.01.201:1 Referat Digitale Archive: Universität zu Köln Institut für Historisch- Kulturwissenschaftliche Informationsverarbeitung WS 2010/ 11 Dozentin: Simone Görl M. A. AM1 Übung: "Strukturen der wissenschaftlicher Informationsverarbeitung"

Mikroverfilmung im Kulturgüterschutz

Long-Term Preservation Services, A description of LTP services in a Digital Library environment.

Digitale Agenda: Reflexionsgruppe zur Digitalisierung holt Meinungen über die Förderung des kulturellen Erbes online ein

A successful Kick-Off for the DCA Project: Digitising Contemporary Art for Europeana

Die neue Renaissance, Empfehlungen der Drei Weisen zum Ausbau des europäischen kulturellen Erbes im Netz, Zusammenfassung

Die neue Renaissance, Empfehlungen der Drei Weisen zum Ausbau des europäischen kulturellen Erbes im Netz, The Final Report

GIS-DON archivage numerique fonctionnement enregistrement optique

Jean-Marc Fontaine: Dégradations des disques optiques, Réponses pouvant étre apportées, Journée GIS-DON - 17 novembre 2009

nestor Handbuch 2.0

Ministererklärung zum eGovernment, einstimmig angenommen in Malmö, Schweden, am 18. November 2009

Javier Hernandez-Ros: European CommissionOnline consultation, "Europeana – Next Steps" Results, Member States' Expert Group on Digitisation and Digital Preservation 6th Meeting 19 May 2010

Wim van Dongen APEnet project, Europeana Hierarchical Metadata meeting, workshop on how to display hierarchical objects and their metadata in Europeana, Europeana office – The Hague – 16th of September 2010

William Kilbride: Risk Management in digital preservation. Digital Preservation Coalition, DPC, York, UK.