physics

Ultra Density Optical

Ultra Density Optical is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Ultra Density Optical rather than just read about it. In short: Ultra Density Optical (UDO) is an optical disc format designed for high-density storage of high-definition video and data. The format was introduced by Sony to replace the Magneto-optical disc format.

Key takeaways

Ultra Density Optical belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Ultra Density Optical to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Ultra Density Optical from memory before moving on to harder problems.

Reference excerpt

Ultra Density Optical (UDO) is an optical disc format designed for high-density storage of high-definition video and data. The format was introduced by Sony to replace the Magneto-optical disc format.

Overview An Ultra Density Optical disc, or UDO, is a 133.35 mm (5.25") ISO cartridge optical disc which can store up to 30 GB (gigabytes) of data. The second generation UDO2 media format was introduced in April 2007 and has a capacity of up to 80 GB. It utilizes a design based on the Magneto-optical disc, but uses Phase Change technology combined with a blue violet laser. A UDO/UDO2 disc that can store substantially more data than a magneto-optical (MO) disc. This is due to the shorter wavelength (405 nm) of the blue-violet laser employed. MOs use a 650 nm-wavelength red laser. Because its beam width is shorter when burning to a disc than a red-laser for MO, a blue-violet laser allows more information to be stored digitally in the same amount of space. Current generations of UDO2 media store up to 60 GB.

History UDO optical disc storage media was developed as a replacement for the 9.1 GB Magneto-optical digital storage medium. The Ultra Density Optical was first announced by Sony on November 1, 2000. It was later adopted with heavy investment by Plasmon, a UK technology company with extensive experience with computer archival backup systems and solutions. Currently, UDO/UDO2 is being championed by its development partners Plasmon, Asahi Pentax (responsible for the opto-mechanical assembly design), Mitsubishi Chemical, parent company of the Verbatim media storage brand, and various computer and IT solutions companies. Mitsubishi Chemical is the second major development partner of UDO media and the sole manufacturer of UDO media as of the 4th quarter of 2008. On November 10, 2008, Plasmon creditors (led by Silicon Valley Bank) closed down Plasmon LMS (company) as CEO Stephen 'FX' Murphy was unable to secure funding to keep the money-losing company afloat. The UDO media factory in the UK was shut down and dismantled. On January 13, 2009, Alliance Storage Technologies, a Colorado Springs Manufacturer of optical technology and Service Provider, acquired the assets of Plasmon (including UDO and UDO2 technology) in a liquidation sale. ASTI currently sells and supports UDO technologies sold under the Plasmon brand.

Specifications ECMA-380: Data Interchange on 130 mm Rewritable and Write Once Read Many Ultra Density Optical (UDO) Disk Cartridges –Capacity: 60 Gigabytes per Cartridge – Second Generation

Writing technology UDO uses a Phase Change recording process that permanently alters the molecular structure of the disc surface.

Disc format There are three versions of UDO/UDO media: a True WORM (Write Once Read Many), an R/W (Rewritable), and Compliant WORM (shreddable WORM).

Rewritable The UDO Rewritable format uses a specially formulated Phase Change recording surface that allows recorded data to be deleted and modified. In practice, UDO rewritable media operates like a standard magnetic disc. Files can be written, erased and rewritten, dynamically reallocating disc capacity. Rewritable media is typically used in archive applications where the stability and longevity of optical media are important, but archive records change on a relatively frequent or discretionary basis. Rewritable media is typically used in archive environments where data needs to be deleted or media capacity re-used. True write once The UDO True Write Once format uses a different phase change recording surface than the rewritable media. Unlike rewritable media, the write once recording surface cannot be erased or altered, making Write Once the most stable in terms of data integrity, because the physical record is kept authentic. This level of data integrity is not usually matched by other magnetic disc or tape technologies using normal write once emulation. Compliant write once media UDO Compliant Write Once media has the same operational properties as UDO True Write Once media but with one clear and important difference. Through the use of a specially designed "shred" operation, individual records written to Compliant Write Once media can be destroyed once their retention period expires. The shred function is controlled at an application level and operates only on Compliant Write Once media.

Magneto-optical comparison The table below summarizes the differences between conventional Magneto-Optical specifications and those of the enhanced Ultra Density Optical disc.

Note

Drive mechanism UDO Drives Specifications Summary

Media Load Time 5 s Media Unload Time 3 s Average Seek Time 35 ms Buffer Memory 32 MB Max Sustained Transfer Rate – Read 8 MB/s (this is on the outer diameter of the media only the inner diameter is a max of 4 MB/sec) Max Sustained Transfer Rate – Write 4 MB/s (with verification on outer diameter of media only) MSBF – Mean Swap Between Failure 750,000 load/unload cycles MTBF – Mean Time Between Failure 100,000 hours Interface Wide Ultra 2 LVD SCSI UDO comes in both internal and external drive guises. External drives are also available as part a robotic autoloader. All current drives are designed for heavy duty use.

Laser and optics UDO systems use a blue-violet laser operating at a wavelength of 405 nm, similar to the one used in Blu-ray Disc, to read and write data. Conventional MOs use red lasers at 660 nm. The blue-violet laser's shorter wavelength makes it possible to store more information on a 13 cm sized UDO disc. The minimum "spot size" on which a laser can be focused is limited by diffraction, and depends on the wavelength of the light and the numerical aperture of the lens used to focus it. By decreasing the wavelength, using a higher numerical aperture (0.85, compared with 0.575 for MO), the laser beam can be focused much more tightly. This produces a smaller spot on the disc than in existing MOs, and allows more information to be physically stored in the same area. [1] The opto-mechanism design of current Plasmon UDO drives was jointly developed with Asahi Pentax.

Applications

Archival storage Currently UDO has an expected data archival life of around 50 years. Apart from the storage size, the discs (like Magneto Optical discs) are designed for durability and long term reliability.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Ultra Density Optical

Start with the simplest possible case. Write down what Ultra Density Optical claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Ultra Density Optical before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Ultra Density Optical ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Ultra Density Optical

In research: Ultra Density Optical appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Ultra Density Optical in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Ultra Density Optical is common in secondary-school and first-year university syllabi. It links to neighbouring topics Audiovisual introductions in 2000, Japanese inventions, Optical computer storage media, so understanding it makes those chapters shorter.
In everyday life: Look for Ultra Density Optical outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Ultra Density Optical in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Ultra Density Optical means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Ultra Density Optical out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ultra Density Optical in simple terms?

Why does Ultra Density Optical matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Ultra Density Optical?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Ultra Density Optical.