Hello,

We noticed you're browsing in private or incognito mode.

To continue reading this article, please exit incognito mode or log in.

Not an Insider? Subscribe now for unlimited access to online articles.

A Better Optical Switch

Fiber Optics: Holography takes optical switching to nanosecond speeds.

The dream of a speedy all-optical Internet has so far been thwarted by a vexing bottleneck: optical switches must convert data to an electrical signal to switch data from one optical fiber to the next, then convert the data back to optical to speed it on its way. This conversion requires costly and bulky equipment, and when you scale up to the high-bandwidth data streams demanded by the latest optical networks, these switches are no longer cost-effective. A better solution is an all-optical device that can affordably switch gigabytes of data without skipping a beat.

Researchers have tried optical switching devices such as arrays of tiny mirrors, liquid crystals and ink-jet bubbles, but an Israeli startup called Trellis Photonics may have a better idea: holograms. The company claims its new “electroholographic” device is as scalable as mirrors while offering faster switching and better reliability. Developed by Aharon J. Agranat at the California Institute of Technology and the Hebrew University of Jerusalem, Trellis’s technology creates ribbonlike holograms within crystals that are arranged in rows and columns like a trellis. When electrically charged, the holograms can selectively deflect specific colors onto new paths, while the rest of the light wavelengths pass through unaffected.

The device can switch data in as little as 10 nanoseconds (billionths of a second), which is comparable to the speed of optical-electrical switches, and future versions will switch even faster. Yet in today’s market, an optical switch is judged by the number of wavelengths it can process, not the speed of its switching. “At this point, nanosecond switching doesn’t really matter,” says Jay Patel, an analyst at the Yankee Group. But Sterling Perrin, an analyst at IDC, suggests the switch’s quickness may eventually bear fruit when intelligent optical routers are developed that can analyze and optimize the path of individual data packets. Says Perrin, “That’s when you’ll need a switch with nanosecond speeds.”

This story is part of our March 2001 Issue
See the rest of the issue
Subscribe

Trellis Photonics recently received a secondary $25 million round of venture funding. Carriers will beta-test the Trellis device this spring, with general availability planned for the fall. If it lives up to its billing, the dream of an all-optical network could be closer than expected.

Tech Obsessive?
Become an Insider to get the story behind the story — and before anyone else.

Subscribe today
Want more award-winning journalism? Subscribe and become an Insider.
  • Insider Plus {! insider.prices.plus !}* Best Value

    {! insider.display.menuOptionsLabel !}

    Everything included in Insider Basic, plus the digital magazine, extensive archive, ad-free web experience, and discounts to partner offerings and MIT Technology Review events.

    See details+

    Print + Digital Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

    Technology Review PDF magazine archive, including articles, images, and covers dating back to 1899

    10% Discount to MIT Technology Review events and MIT Press

    Ad-free website experience

  • Insider Basic {! insider.prices.basic !}*

    {! insider.display.menuOptionsLabel !}

    Six issues of our award winning print magazine, unlimited online access plus The Download with the top tech stories delivered daily to your inbox.

    See details+

    Print Magazine (6 bi-monthly issues)

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

  • Insider Online Only {! insider.prices.online !}*

    {! insider.display.menuOptionsLabel !}

    Unlimited online access including articles and video, plus The Download with the top tech stories delivered daily to your inbox.

    See details+

    Unlimited online access including all articles, multimedia, and more

    The Download newsletter with top tech stories delivered daily to your inbox

/3
You've read of three free articles this month. for unlimited online access. You've read of three free articles this month. for unlimited online access. This is your last free article this month. for unlimited online access. You've read all your free articles this month. for unlimited online access. You've read of three free articles this month. for more, or for unlimited online access. for two more free articles, or for unlimited online access.