SOUTHAMPTON, U.K. -- Southampton Photonics, a leading supplier of next-generation fibre-based components and subsystems for the worldwide optical networking marketplace, has shipped what are believed to be the first commercially available 25GHz channel separation fibre Bragg gratings (FBGs). The BragNet™ FBGs were shipped to a major fibre-optic systems vendor and involve a patented technology breakthrough which enables the number of wavelengths of light that can be sent down a single fibre-optic cable to be increased, thereby expanding network capacity and lowering operator costs.

FBGs are components vital for filtering, routing, and conditioning the individual wavelengths of light that carry data down a single fibre cable in a process known as Dense Wave Division Multiplexing (DWDM). More accurate FBGs, that is with lower channel separations, allow a greater number of wavelengths, and therefore more data to be transported over the network. Current FBGs achieve channel separations of 100GHz and 50GHz.

The patented design and fabrication technique developed by Southampton Photonics not only produces the most accurate FBGs available, but automates the time-intensive design and production processes. This enables the company to speed up grating production dramatically and produce standard and customized FBGs in high volume and record time: a few days versus 6 - 8 weeks.

"We are pleased to announce the first shipments of 25GHz new-technology high precision fibre Bragg gratings," said Don Spalinger, President and co-founder of Southampton Photonics. "Our new automated process allows us to design very precise, low distortion gratings quickly while letting us customize to high volume. We believe it will prove an invaluable benefit to our customers and a key differentiator for our company."

The new Southampton Photonics process has tremendous implications for the optical components market, which is experiencing intense demand and short supply. Telecom market researchers Ryan Hankin & Kent (RHK) predict that the North American market for DWDM components, which reached $3.5 billion in 1999, will continue to grow at 50% a year and become a $24 billion market by 2004. By establishing itself as a leader in this growing market, Southampton Photonics is aiming to become the standard ingredient in any high performance DWDM system.

A New Design and Manufacturing Process

Today, fibre Bragg gratings are made by writing a pattern onto a fibre using a UV laser and a custom "phase mask" similar in concept to those used to fabricate semiconductor chips. Grating characteristics and quality under this method are determined by the characteristics of the mask itself. This "hand crafted" approach is time consuming and inefficient, with customization of a grating typically running 6 - 8 weeks, and cannot achieve the necessary filter required for the closely-packed DWDM systems being developed for today’s high performance networks.

Instead of writing every grating with a custom phase mask, Southampton Photonics designed several generic masks that can be used to make any type of grating. By carefully scanning the fibre with a laser, Southampton Photonics is able to more accurately control the writing of the grating - significantly improving performance.

In addition, the company has developed an automated process for setting up a manufacturing run, allowing it to feed customers’ design specifications directly into a computer driven manufacturing model. As a result the company has removed around 75% of the manual labour involved and can manufacture gratings from product definition to customer testable prototype in a matter of days, rather than the 6-8 weeks typical of traditional fibre grating design and fabrication.

A Revolution in Critical Component Design

Fibre Bragg gratings are a critical technology with applications in almost every component in a DWDM (dense wave division multiplexing) optical network. DWDM networks function by combining multiple wavelengths of light (each containing a single ‘channel’ of information) onto a single glass fibre, and fibre Bragg gratings function like a series of microscopic mirrors with different refractive properties that can manipulate an individual wavelength of light by routing it, or combining it with other wavelengths, while allowing the other wavelengths to pass through.

With its breakthrough fibre Bragg grating design and manufacturing process, Southampton Photonics has the ability to design fibre Bragg gratings that will allow DWDM networks to carry many more channels – and thus more data – over a single fibre than ever before possible, by significantly enhancing the control over each channel. The more precise the grating, the greater the signal integrity of each wavelength, and the more wavelengths that can be packed into a fibre. This in turn allows Southampton Photonics customers to dramatically increase the capacity – and therefore revenue – of their fibre optics networks.

Current standard DWDM systems can multiplex (combine) as many as 40 wavelengths onto a single fibre, but with Southampton Photonics' new fibre Bragg gratings, the company is already working on gratings capable of 320 channel per fibres and beyond, delivering at many times the current capacity.

Taking Fibre Bragg Gratings to Market: A Variety of ApplicationsFibre Bragg gratings comprise one of Southampton Photonics’ three pillars of expertise along with specialty fibres and amplifiers and are among the first products it has shipped. Its precision FBGs will be sold as stand-alone filters (for use in OADMs, multiplexers and other components), and integrated into the company’s Interleavers, and DFB Fibre Laser Arrays. Southampton Photonics is currently running field trials of each product with major North American optical network systems manufacturers.

http://www.southamptonphotonics.com