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US 6,608,945 B2Granted
Self-aligning modulator method and associated apparatus
AssigneeOptronx, Inc.
InventorShrenik Deliwala
Life of this patent
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AssigneeOptronx, Inc.
InventorShrenik Deliwala
Estimating the term…
A self-aligned optical modulator that modulates an input optical signal in order to generate a modulated output optical signal includes an optical modulator device including a waveguide, a first modulating electrode, a second modulating electrode, and a two-dimensional electron (hole) gas (2DEG) proximate the first modulating electrode, the waveguide includes an input port wherein the input optical signal is introduced into the waveguide, an output port wherein the modulated output optical signal exits the waveguide, and a region of modulating propagation constant disposed along a first length of the waveguide and between the input port and the output port, wherein the input optical signal is guided by total internal reflection in the waveguide, and the waveguide is formed at least in part from an active semiconductor. The first modulating electrode is positioned proximate a first surface of the region of modulating propagation constant and electrically separated from an active semiconductor.
A self-aligned optical modulator that modulates an input optical signal in order to generate a modulated output optical signal, comprising:
A self-aligned optical modulator for modulating the propagation constant level of an optical modulating region of a waveguide, comprising:
A method for self-aligned optical modulation comprising:
A computer readable medium containing software that controls a planar electrode having a prescribed shape positioned proximate a waveguide, said software when executed by a processor causes the processor to perform the steps of:
A self-aligned optical modulator for modulating light flowing through a waveguide by modulation of a propagation constant level of the waveguide, the self-aligned optical modulator comprising:
An apparatus for modulating an input optical signal in order to generate a modulated output optical signal, comprising:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
From the US filing history. Foreign family members aren’t listed.
Comprising arrayed waveguide grating [AWG] devices, i.e. with a phased array of waveguides: characterised by the arrayed waveguides, e.g.…
Nanooptics
Prisms: prism arrays
Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings: of the optical waveguide type
Term ended 22 Dec 2021 (estimated)
This invention relates to optical devices, and more particularly to optical waveguide devices.
In the integrated circuit industry, there is a continuing effort to increase device speed and increase device densities. Optical systems are a technology that promise to increase the speed and current density of the circuits. Optical devices, such as optical modulators are used in these optical systems. Such optical modulators can be used to perform a variety of functions in integrated circuits such as signal transmission and attenuation. Optical modulators typically require different devices to phase modulate or amplitude modulate light.
Optical devices that perform different functions are typically formed and shaped differently in order to perform the different functions. As such, each type of optical device, and each size of the same optical device type, has to be manufactured distinctly. Therefore, the production of precision optical devices is expensive. Additionally, optical devices are susceptible to changes in temperature, contact, pressure, humidity, etc. As such, the optical devices are typically contained in packaging that maintains the conditions under which the optical devices are operating. Providing such packaging is extremely expensive. Even if such packaging is provided, passive optical devices may be exposed to slight condition changes. As such, the passive optical devices perform differently under the different conditions. The modulators will modulate the light a different amount. If the characteristics of a passive optical device is altered outside of very close tolerances, then the optical device will not adequately perform its function. In other words, there is no adjustability for passive optical devices such as modulators.
The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate the presently preferred embodiment of the invention, and, together with the general description given above and the detailed description given below, serve to explain features of the invention.
FIG. 1 shows a front cross sectional view of one embodiment of an optical waveguide device including a field effect transistor (FET);
FIG. 2 shows a top view of the optical waveguide device shown in FIG. 1;
The present disclosure provides multiple embodiments of optical waveguide devices in which light travels within a waveguide. Different embodiments of optical waveguide devices are described that perform different functions to the light contained in the waveguide. Altering the shape or structure of an electrode(s) can modify the function of the optical waveguide device 100.
There are a variety of optical waveguide devices 100 that are described in this disclosure. Embodiments of optical waveguide devices include a waveguide located in a Field Effect Transistor (FET) structure as shown in FIGS. 1 to 3; a waveguide associated with metal oxide semiconductor capacitor (MOSCAP) structure is shown in FIG. 4; and a waveguide located in the High Electron Mobility Transistor (HEMT) as shown in FIG. 5. In MOSCAPs, one or more body contact(s) is/are separated from the gate electrode by a semiconductor waveguide and an electrical insulator. In the embodiment of FETs applied to the present invention, a substantially constant potential conductor is applied between the source electrode and the drain electrode to maintain the two electrodes at a common voltage. When the source electrode of a FET is held at the same potential as the drain electrode, the FET functionally operates as, and may be considered structurally to be, a MOSCAP. To make the description for the above embodiments more uniform, the term “body contact electrodes” is used to describe either the body contact at the base of the MOSCAP or the substantially common potential source electrode and drain electrode in the FET.
The application of the voltage between the gate and body contact(s) predominantly changes the distribution of free-carriers (either electrons or holes) near the semiconductor/electrical insulator boundary. These essentially surface localized changes in the free carrier distributions are referred to as two-dimensional electron gas or 2DEG included in MOSCAPs. In a FET structure, for example, an increase in the application of the bias leads consecutively to accumulation of charges (of the same type as the semiconductor i.e. holes in a p-type and electrons in n-type, depletion, and finally inversion. In 2DEGs, the polarity of semiconductor is opposite the type of the predominant free carriers, i.e. electrons in p-type or holes in n-type). In a High Electron Mobility Transistor (HEMT), the electron (hole) distribution formed just below the surface of the electrical insulator is referred to as 2DEG because of particularly low scattering rates of charge carriers. At any rate, for the purposes of clarity, all of the above shall be referred to as 2DEG signifying a surface localized charge density change due to application of an external bias.