Market report: Optical MEMS: the future of all-optical networks

17 Jun 2002

The emerging field of optical micro-electromechanical systems promises to take a key role in telecoms networks. Phillip Hill looks at Europe's strengths in this field.

From Opto & Laser Europe April 2001

Lucent's micromirrors

A recent report from market-research firm Yole Développement of Lyon, France, stresses that, although Europe has a rich and high-quality R&D environment in optical micro-electromechanical systems, little of the research into these devices has filtered down to the manufacturing floor.

Eric Mounier from Yole Développement commented: "Many research institutes cover the same field of development, but often with insufficient resources."

The optical telecommunications market is growing at a dramatic rate. According to market-research firm RHK, the fibre-optic-component market will increase from USD 5.5 billion in 1999 to USD 21.3 billion in 2003 (an annual growth rate of 40%). The development of dense wavelength division multiplexing (DWDM) has led to an unprecedented increase in the demand for optical components. DWDM systems currently use the expensive optics-to-electronics-to-optics (OEO) conversion to route and switch optical signals.

Deploying DWDM in optical rings in a cost-effective way requires optical add-drop multiplexers and optical cross-connects to overcome the need for OEO conversion.

Currently there are five competing technologies that are used to produce optical components: integrated optics, fibre optics, thin films, micro-optics and micro-electromechanical systems (MEMS)/optical MEMS.

As far as the MEMS technologies are concerned, there are two kinds of microsystems. MEMS are passive components - V-grooves and alignment parts, for example. Optical MEMS are microsystems for wavelength handling, either with a wavelength shift (this type of component uses materials other than silicon, such as InP) or without a wavelength shift, such as micromachined micromirror arrays or optomechanical switches.

In Europe there are about 10 companies that make optical MEMS products - mainly optical switches. For example, Ilotron - a spin-off from the Photonic Networks Research Centre at the University of Essex in the UK - develops all-optical network routers based on optical MEMS. Ilotron also integrates micromirror technology from several firms, including OMM in the US.

Compared with the US, few European businesses make optical MEMS products. "The development cost of these technologies is high and can scarcely be afforded by small firms. Ilotron is an exception, because it does not make components but integrates them into systems," said Mounier.

The other principal companies involved in MEMS are: Amic of Sweden, Optical Micro Devices of the UK, Optospeed of Switzerland, Piezosystem Jena, Germany, and Sercalo Microtechnology, Lichtenstein. New players are emerging, including CSEM in Switzerland, TMP in the Netherlands (now Kymata Netherlands) and Tronic's Microsystems in France.

Micromirror switch

The most commonly marketed active component is the optical switch. Sales in optical-switching systems are forecast to grow from USD 247 million in 2000 to USD 4 billion in 2004, according to market-research firm Pioneer Consulting.

IMM Mainz in Germany makes an optical switch based on polymer technology, while the start-up company Sercalo Microtechnology is developing a device that is based on silicon micromirror technology. Piezosystem Jena has optical switches that are based on piezoceramic actuation technology. The company is still developing its range of optical-fibre switches, with new developments ongoing (for example, a 4 ¥ 4 matrix and a 1 ¥ 16 fibre optical switch). LEOM (France) is currently developing a tunable filter based on InP material. The most complex components that can be manufactured using optical MEMS technology - optical cross-connects for network management, for example - are currently being developed by large companies that can afford the development costs. Demand is not uniform in the network, so there is a growing need for reconfiguration of parts of it (to create regions of higher capacity). Optical MEMS, such as WDM add/drop, optical cross-connects and optical switches, are suitable for reconfiguration.

According to market-research firm ElectroniCast, the global consumption of optical add-drop multiplexers will grow from USD 23 million to USD 1.64 billion in 2003 and to USD 7.2 billion in 2008.

MEMS technology is ideal for large (more than 1000 ¥ 1000 inputs/outputs) optical cross-connects that can reconfigure the network in a short time (less than 50 ms) in response to traffic flow. Moreover, MEMS are free-space devices and each wavelength channel is physically separate from its neighbour. They could be the answer to the debate on all-optical versus OEO conversion.

Access to manufacturing is a vital issue for companies that are looking for optical MEMS products. There are two kinds of player: manufacturers with low intellectual property rights (IPR), such as Tronic's Microsystems, and IPR players without production units, such as Xros in the US.

In Europe, industrial transfer and creation of start-ups are strongly encouraged, even in state-owned laboratories.

Mounier said: "A European belief is that the creation of employment will emerge from the setting up of new start-ups by research institutes and laboratories. Europe is aware that optical MEMS added value is in the system and subsystem and not in the component itself. That is why the marketing position of Ilotron is so interesting."

Established microsystem foundries are now moving into optical MEMS activities. This is true for Twente Microproducts in the Netherlands, Gefran Spa in Italy and Tronic's Microsystems (which now makes micromirrors). Some firms prefer to be component integrators - such as Alcatel, which buys optical MEMS from OMM in the US.

There are few organizations that develop and manufacture components; this is a crucial point for the telecoms players that need access to production facilities.

"Companies are being acquired earlier and earlier in their development cycle," said Mounier. "Large businesses are gambling on not-yet-proven technologies."

US firms have more mature products that use optical MEMS technology than European companies, says Mounier. "US businesses have made major breakthroughs in optical MEMS. Industrial products that integrate optical MEMS were presented for the first time at OFC 2000.

"One strength of the US MEMS industry is the presence of 'open' MEMS foundries that offer custom optical-MEMS devices. Europe lacks such facilities, but there is a trend towards offering customized devices." Optical-MEMS activity in the US is a few years ahead of that in Europe. Large companies, for example Lucent Technologies and Texas Instruments, have developed large-matrix cross-connects using micromirrors as the base element. Moreover, says Mounier, amazing technological achievements have been realized by start-ups. Such performances force European firms to use US companies as providers.

In the field of optical MEMS, Europe has an excellent research base, a well qualified workforce and a strong knowledge base. It also enjoys a top-ranking position in complementary microsystem technologies, such as micro-optics and replication techniques as well as in packaging and interconnect techniques. In theory, Europe should be well placed to exploit a booming market. For the full report "Components for wavelength handling in all-optical telecommunications networks in Europe", contact Eric Mounier, Yole Développement, fax +33 4 7283 0183.