CN1588149A - Tunable light wave guide dispersion compensator controlled by two-section erverse electrode oriented coupler - Google Patents

Abstract

The invention discloses an adjustable optical waveguide dispersion compensator controlled by a double-section reverse electrode directional coupler. Parallel input/output optical waveguides are set in the waveguide part where the optical waveguide microring forms a closed loop to form a directional coupler. The effective length of the directional coupler is between 1 and 3 times the coupling length. In order to take into account the length of the coupling effect at the gradual separation, two sections of driving electrodes with the same length are set on the directional coupler, and the two sections of electrodes are oppositely set on the two waveguides constituting the directional coupler, forming a double-section opposite electrode Structured 2×2 input steerable directional coupler. The adjustable coupling mechanism of this structure can realize full-range coupling adjustment, and can have a curved shape. Even for circular optical microrings, no special structural treatment is required, and the circumference of the optical microrings will not be increased. . This brings great flexibility to device design. In addition, it also has great flexibility in the design and implementation of multi-level cascading.

Description

Tunable Optical Waveguide Dispersion Compensator Controlled by Dual Opposite Electrode Directional Couplers

technical field

The invention relates to optical components, in particular to an adjustable optical waveguide dispersion compensator.

Background technique

With the increase of the communication rate in optical communication, the dispersion in the optical fiber has become the main factor limiting the optical transmission distance. Therefore, it has become extremely important to compensate the dispersion of the light wave transmitted in the optical fiber. At present, many optical dispersion compensation schemes have been proposed, among which the integrated optical waveguide optical dispersion compensator with optical microring structure based on the principle of all-pass filter is a very promising scheme.

The optical waveguide dispersion compensator using the optical microring structure needs to have the input/output coupling control mechanism of the optical microring to realize the adjustable dispersion compensation function. Mai Desheng and others of Bell Labs in the United States have obtained a coupling control using a 2×2 Mach-Zehnder interference structure, but due to the limitation of the mechanism, there are limitations in the realization of the coupling coefficient, and, due to the structural In order to meet the requirements, the circumference of the entire optical microring has to be increased, which is not conducive to the application.

Contents of the invention

The object of the present invention is to provide an adjustable optical waveguide dispersion compensator controlled by a double-section reverse electrode directional coupler, whose dispersion compensation adjustable control function is realized by using a double-section reverse electrode structure directional coupler.

The technical solution adopted by the present invention to solve the technical problem is: in the waveguide part of the optical waveguide micro-ring forming a closed loop, parallel input/output optical waveguides are set to form a directional coupler, and the effective length of the directional coupler is used for coupling Between 1 and 3 times the length, the effective length is the length that takes into account the coupling effect at the gradient separation point. Two driving electrodes of the same length are set on the directional coupler, and the two sections of electrodes are set in opposite directions to form the directional coupler. A 2×2 input controllable directional coupler with a double-section opposite electrode structure is formed on the two waveguides.

The optical waveguide microring can be circular, and the corresponding input/output waveguide constitutes an arc-shaped part with a directional coupler, which has the same center of circle as the optical waveguide microring, and the directional coupler at this time has a curved shape.

The optical waveguide microring can be in the shape of a track and field, the corresponding input/output waveguide adopts a straight waveguide, and forms a directional coupler parallel to the straight waveguide with the straight waveguide part of the optical waveguide microring.

The advantages that the present invention has:

1) It can realize full-range coupling adjustment, which provides a solution for the design of integrated optical waveguide optical dispersion compensator;

2) Since the directional coupler structure is adopted, and the directional coupler can have a curved shape, even for a circular optical microring, no special structural treatment is required, and the circumference of the optical microring will not be increased. This brings great flexibility to the design of the device;

3) Since the adjustable optical dispersion compensator with required characteristics often needs to be realized through a multi-level cascading scheme, the circular structure in the present invention can make good use of the circumference of the circle for coupling control, which gives The design and implementation of multi-level cascading also brings great flexibility.

Description of drawings

Figure 1 is an adjustable optical waveguide dispersion compensation controlled by a double-section reverse electrode directional coupler. In the figure, the optical waveguide microring is circular;

Figure 2 is an adjustable optical waveguide dispersion compensator controlled by a double-section reverse electrode directional coupler. In the figure, the optical waveguide micro-ring is in the shape of a track and field track;

Detailed ways

Figure 1 and Figure 2 are tunable optical waveguide dispersion compensators controlled by double-section opposite electrode directional couplers. In FIG. 1, the optical waveguide microring 1 is circular, and in FIG. 2, the optical waveguide microring 11 is in the shape of a track and field track. Among them, 1 and 11 are optical waveguide microrings, 2 and 12 are input/output coupling optical waveguides, 3 and 13 are directional coupler parts with double-section inverted electrode structure, driving electrodes 4 and 14 and driving electrodes 5 and 15 The double-section reversed electrode parts are formed respectively. Of course, it should be explained here that the electrode structure is only schematic, and it will be specifically set according to the driving of the refractive index effect used.

There are many implementations of the present invention, and the silicon dioxide multilayer planar optical waveguide process is used as an example here, but it is by no means limited to this example.

Using a silicon wafer or glass with a certain thickness of silicon dioxide layer as the substrate material, grow a doped silicon dioxide core layer with a relatively high refractive index value, and use photolithography and dry etching to produce an adjustable The core layer waveguide of the optical dispersion compensator. After the core layer is completed, an upper confinement layer with a slightly lower refractive index is grown again. For silica optical waveguide, its thermo-optic effect can be used to realize the tunable characteristics of the device. That is, a layer of metal chromium is vaporized on the upper limiting layer, and a heating electrode with a double-node inverted electrode structure is fabricated on the directional coupler by photolithography and etching. The thermo-optic effect is excited by this heating electrode, so as to obtain a 2×2 adjustable directional coupler, realize the adjustable coupling between the optical microring and the input/output optical waveguide, and finally obtain an adjustable optical dispersion compensator.

Claims (3)

1. An adjustable optical waveguide dispersion compensator controlled by a double-section reverse electrode directional coupler, characterized in that: parallel input/output optical waveguides are set along the waveguide part where the optical waveguide micro-ring forms a closed loop to form a directional Coupler, the effective length of the directional coupler is between 1 time and 3 times the length of the coupling length, the effective length is the length that takes into account the coupling influence at the gradual separation, and two driving sections of the same length are set on the directional coupler The electrodes are oppositely arranged on the two waveguides constituting the directional coupler to form a 2×2 input controllable directional coupler with a double-section opposite electrode structure. 2. The adjustable optical waveguide dispersion compensator controlled by a double-section reverse electrode directional coupler according to claim 1, characterized in that: the optical waveguide micro-ring is circular, and the corresponding input/output waveguide and The arc-shaped part with the directional coupler has the same circle center as the optical waveguide microring, and the directional coupler at this time has a curved shape. 3. The adjustable optical waveguide dispersion compensator controlled by a double-section reverse electrode directional coupler according to claim 1, characterized in that: the optical waveguide microring is in the shape of a track and field track, and the corresponding input/output waveguide adopts The straight waveguide and the straight waveguide part of the optical waveguide microring constitute a directional coupler parallel to the straight waveguide.

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