May 7, 2004 Glasgow, Scotland -- Intense Photonics Ltd. says it is fabricating chips that integrate up to a 100 or more multi-function optical components on a single die. Intense sites its quantum well intermixing (QWI) process as a key to its success.
According to the company, the QWI process achieves reliable yields when fabricating multiple optical functions onto a chip because -- unlike regrowth-based compound semiconductor processes -- it fabricates all the component elements in a single stage. This makes it possible for OEMs to conceive system architectures based on highly integrated optical components.
For example, the company has developed a chip that contains a GaAs laser array operating at 980 nm, the wavelength for EDFA pumping. Each device in the array is individually addressable, and delivers >220 mW of power at the output facet. Two further passive waveguide components are integrated on either side of each laser element - providing serial integration in each channel. This further improves the yield by raising the threshold for catastrophic optical damage (a common laser failure mode), and relaxing the mechanical cleaving and packaging alignment tolerances.
Such an array could be used to lower the costs of building EDFA pumps for metro optical networks. However, an adjustment to the bandgaps of each laser would make arrays for WDM applications. Alternatively, the different component functions required for a WDM transmission chain could be serially integrated.
"Highly integrated optical devices have the potential to reduce optical system costs by one or two orders of magnitude," says John Marsh, CTO of Intense.