A monolithically integrated displacement sensor has been fabricated in the GaAs/AlGaAs material system. The device is configured as a Michelson interferometer and consists of a DBR laser, a directional coupler, transparent waveguides and a photodetector. Interference fringes could be seen at a measurement distance of up to 45cm, requiring only the alignment of an external GRIN lens for beam collimation.
Tobias Kippenberg, Dalziel Joseph Wilson, Miles Henry Anderson
Nicolas Grandjean, Jean-François Carlin, Denis Martin