Modulator for analog applications
AssigneeAgere Systems Optoelectronics Guardian Corp.
InventorsRichard Bendicks Bylsma, Leonard Jan-Peter Ketelsen, Sharon Kay Sputz
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Abstract
The invention in one aspect is an optical modulator which includes a waveguide region of semiconductor material. In order to achieve a gradual, essentially linear transfer function, the bandgap of the waveguide region is graded along the direction of light propogation or perpendicular thereto. In accordance with another aspect, the invention is an electroabsorption modulated laser where the portion of the waveguide region defining the modulator has a graded bandgap. In accordance with a method aspect, the waveguide region of the modulator is grown using a mask having a varying width to achieve the graded bandgap.
Claims15
An optical modulator comprising a waveguide region of semiconductor material wherein the waveguide region has a bandgap wavelength which varies along a path perpendicular to the path of light propagation.
An electroabsorption modulated laser comprising a laser and a modulator formed on a substrate and including a waveguide region of semiconductor material wherein the portion of waveguide region defining the modulator has a bandgap wavelength which varies along a path perpendicular to the path of light propagation.
A method of operating an optical modulator with a waveguide region of semiconductor material wherein the waveguide region has a bandgap wavelength which varies along a certain direction, comprising the steps of:
- propogating light through the modulator in the said direction;
- and
- applying an analog signal to said modulator to produce an analog output optical signal from the modulator.
A method of operating an optical modulator with a waveguide region of semiconductor material wherein the waveguide region has a bandgap wavelength which varies along a certain direction, comprising steps of:
- propogating light through the modulator in a direction which is perpendicular to said certain direction;
- and
- applying an analog signal to said modulator to produce an analog output optical signal from the modulator.
Dependencies are inferred from the claim text.