An integrated silicon-on-insulator continually tunable optical delay line for optical coherence tomography

We describe a new integrated rapidly tunable optical delay line optimized for optical coherence tomography (OCT) systems. The integrated system uses a planar waveguide and echelle gratings combined with a specially designed micro-electromechanical system (MEMS) mirror. These components are all fabricated on the same die, thus enabling a very compact and cost effective device. The delay line system has a simulated scanning speed of more than 10 kHz and can provide a continuously tunable variable delay difference of 6.7 ps. The whole system fits on a chip of 12 mm by 8 mm.