May 11 2010
All optics research requires precise alignment of optical components to ensure that light passes efficiently from one element to the next. At the micro-scale, however, the process is much more delicate and complicated. Now, an alignment mechanism integrated onto a silicon chip to allow quick and cheap optical optimization has been demonstrated by Qingxin Zhang and co-workers from the A*STAR Institute of Microelectronics in Singapore.
Zhang and his team used a micro-electromechanical system (MEMS) to precisely align a laser diode made from a semiconductor, either InGaAsP or InGaAIAs, with a silicon photonic circuit. While silicon has had unrivalled success in the electronics industry, the same is not true for photonics applications owing to its poor light-emitting capacity. This means that lasers made from another type of semiconductor must be mounted onto the chip. Ensuring that such emitters line up with the silicon components often requires expensive, high-precision mechanical translation stages. "An integrated approach offers lower processing cost and higher device performance than traditional silicon-photonics packaging," notes Zhang.
MEMS are micrometer-scale mechanical actuators that move in response to thermal expansion induced by an applied voltage. "A MEMS platform can be applied to hybrid integrated silicon photonics for applications that combine both optical transmitters and transceivers," explains Zhang.
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