Picosecond AlxGa1−xAs modulation-doped optical field-effect transistor sampling gate

New modulation-doped Alx Ga1−xAs/GaAs metal-semiconductor field-effect photodetectors have been fabricated and tested in a novel picosecond optical sampling gate configuration. The rise time was measured to be 12 ps, with a full width at half-maximum of 27 ps. The optical electronic picosecond cross-correlation measurement has shown the importance of the two-dimensional electron gas for high-speed operation.