An optical modulator or switch is disclosed. An apparatus includes an
optical splitter disposed in a semiconductor material that splits an
optical beam having a first wavelength into first and second portions.
The first and second portions of the optical beam are to be directed
through first and second optical waveguides, respectively. The first
optical waveguide is also optically coupled to receive a pump optical
beam to amplify and phase shift the first portion of the optical beam. A
diode structure is disposed in the first optical waveguide and is
selectively biased to sweep out free carriers from the first optical
waveguide generated in response to two photon absorption in the optical
waveguide. An optical coupler is disposed in the semiconductor material
and is optically coupled to the first and second optical waveguides to
combine the first and second portions of the optical beam.