Patent ID: 8488917

Claim:
An electro-optic modulator having successive regions comprising: a semiconductor substrate; a first P doped region formed on the semiconductor substrate; a first intrinsic region formed on the semiconductor substrate and in contact with the first P doped region to form a first P-i interface, the first intrinsic region including a first ridge extending along the first P-i interface to effectuate a waveguide that is parallel to the first P-i interface to guide light inside the waveguide along the first P-i interface; an N doped region formed on the semiconductor substrate and in contact with the first intrinsic region to form a first i-N interface that is parallel to the first P-i interface; a second intrinsic region formed on the semiconductor substrate and in contact with the N-doped region to form a second i-N interface parallel to the first i-N interface, the second intrinsic region including a second ridge extending along and being parallel to the second i-N interface; and a second P doped region formed on the semiconductor substrate and in contact with the second intrinsic region to form a second P-i interface that is parallel to the second i-N interface to render the second ridge as a charge reciprocating structure operable to, rapidly, inject charged carriers into, or extract charged carriers from, the waveguide to cause a modulation to a charged carrier density in the waveguide and thus a corresponding optical modulation of guided light in the waveguide when a modulation control signal is applied across a P-i-N-i-P structure that is perpendicular to the waveguide and is collectively formed by successive regions of the first P doped region, the first intrinsic region, the N doped region, the second intrinsic region and the second P doped region.