Optical modulator
AssigneeEmcore Corporation
InventorsHenry A. Blauvelt, Xiaoguang He, Kerry Vahala
Life of this patent
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Abstract
An optical modulator including an information-containing radio frequency signal input; a semiconductor device having an optical input optically for receiving the coherent light beam, and a electrode connected to said radio frequency signal input and having a modulated bias potential so that current is generated in the second semiconductor device and extracted therefrom, while the coherent light beam is optically modulated by the signal changing the carrier density in the semiconductor device.
Claims15
A method for operating an optical modulator that includes a modulator optical waveguide formed on a substrate, the method comprising:
- (a) launching an continuous-wave input optical signal to propagate along the modulator optical waveguide, the input optical signal being characterized by an input optical power level;
- and
- (b) applying an electrical modulation signal to a modulator electrode positioned over a semiconductor modulator active region of the modulator optical waveguide so as to modulate an optical transmission level of the input optical signal through the modulator resulting in a modulated output optical signal emitted from the modulator,
- wherein:
- (c) the optical modulator is characterized by a zero-current modulator optical transmission level that is less than 100% and occurs at a positive modulator bias voltage level that results in charge carriers being neither injected into nor extracted from the modulator active region;
- (d) an electrical modulation signal level that causes charge carriers to be injected into the modulator active region results in a modulator optical transmission level higher than the zero-current modulator transmission level;
- and
- (e) an electrical modulation signal level that causes charge carriers to be extracted from the modulator active region results in a modulator optical transmission level lower than the zero-current modulator transmission level.
Dependencies are inferred from the claim text.