CN118011705A - On-chip integrated amplifier - Google Patents

Abstract

The present disclosure provides an on-chip integrated amplifier comprising: the first multimode interference structure and the second multimode interference structure are respectively used for dividing the signal light and the pump light into two beams; the optical switch is respectively connected with one output of the first multimode interference structure and one output of the second multimode interference structure, and performs position exchange on one signal light and one pump light; the first wavelength division multiplexing structure is used for coupling the other path of signal light output by the first multimode interference structure with one path of pumping light output by the optical switch; the second wavelength division multiplexing structure is used for coupling the other path of pump light and one path of signal light; the first waveguide amplifier and the second waveguide amplifier are used for amplifying signal light in the coupled light output by the first waveguide amplifier and the second waveguide amplifier; the third wavelength division multiplexing structure and the fourth wavelength division multiplexing structure are used for separating the amplified signal light from the pump light; and the third multimode interference structure is used for combining all paths of signals into beams.

Description

On-chip integrated amplifier

Technical Field

The present disclosure relates to the field of optoelectronics, and in particular, to an on-chip integrated amplifier.

Background

With the advent of a new technological revolution, industries such as artificial intelligence, internet of things, cloud computing and the like put higher technical demands on information transmission and processing. Photonic chips with high speed, low loss and relatively mature technology are expected to meet such technological requirements. At present, photonic integrated circuits have developed a great deal of new applications in the fields of 5G communication, big data centers, optical computing and the like. However, large-scale integrated photonic circuits inevitably cause signal attenuation, and optical amplifiers are required to amplify the attenuated signals, so they are an important component of integrated photonic platforms. The current rare earth ion doped waveguide amplifier can realize larger gain for small signal power, but when the input signal power is increased, non-radiative recombination of signal light can be caused, and the signal to noise ratio is reduced, so that the gain is reduced, and the application of the waveguide amplifier in the high-power field is limited to a certain extent.

Disclosure of Invention

In view of the foregoing, the present disclosure provides an on-chip integrated amplifier to solve the foregoing technical problems.

One aspect of the present disclosure provides an on-chip integrated amplifier comprising: a first input optical waveguide for inputting signal light; a second input optical waveguide for inputting pump light; the first multimode interference structure is connected with the first input optical waveguide and is used for dividing the signal light into two beams according to a first optical power ratio; the second multimode interference structure is connected with the second input optical waveguide and is used for dividing the pump light into two beams according to a second optical power ratio; the two input ports are respectively connected with one path of output of the first multimode interference structure and one path of output of the second multimode interference structure, and the two output ports are used for carrying out position exchange on one path of signal light output by the first multimode interference structure and one path of pump light output by the second multimode interference structure; the first wavelength division multiplexing structure is characterized in that two input ports are used for inputting another path of signal light output by the first multimode interference structure and one path of pump light output by the optical switch, and the other path of signal light and the one path of pump light are optically coupled; the second wavelength division multiplexing structure is characterized in that two input ports are used for inputting another path of pump light output by the second multimode interference structure and one path of signal light output by the optical switch and for coupling the other Lu Bengpu light and the one path of signal light; the first waveguide amplifier and the second waveguide amplifier are respectively connected with the first wavelength division multiplexing structure and the second wavelength division multiplexing structure and are used for amplifying signal light in coupled light output by the first waveguide amplifier and the second waveguide amplifier; the third wavelength division multiplexing structure and the fourth wavelength division multiplexing structure are respectively connected with the first waveguide amplifier and the second waveguide amplifier and are used for separating the amplified signal light from the pump light; and the third multimode interference structure is connected with the third wavelength division multiplexing structure and the fourth wavelength division multiplexing structure and is used for combining the signals into beams.

According to an embodiment of the present disclosure, the first waveguide amplifier and the second waveguide amplifier have different waveguide lengths to compensate for a phase difference of each path of the signal light.

According to an embodiment of the present disclosure, the optical power of one path of the signal light output to the optical switch is greater than that of the other path of the signal light, and the optical power of one path of the pump light output to the optical switch is greater than that of the other path of the pump light.

According to an embodiment of the present disclosure, the first input optical waveguide and the second input optical waveguide are straight waveguides.

According to an embodiment of the present disclosure, the first, second, third and fourth wavelength division multiplexing structures are tilted multimode interferometers or multimode waveguide grating structures.

According to an embodiment of the present disclosure, the optical switch is a mach-zehnder type or micro-ring type structure.

According to an embodiment of the present disclosure, the first waveguide amplifier and the second waveguide amplifier are rare earth ion doped helical ridge waveguide amplifiers.

According to an embodiment of the present disclosure, the doping ions of the first waveguide amplifier and the second waveguide amplifier are materials with an amplification band of C-band.

According to an embodiment of the present disclosure, the dopant ions are erbium ions or a combination of erbium ions and erbium ions.

According to the embodiment of the disclosure, the signal light is located in the C band, and the wavelength of the pumping light is 980nm or 1480nm.

The above at least one technical scheme adopted in the embodiment of the disclosure can achieve the following beneficial effects:

The on-chip integrated amplifier provided by the disclosure utilizes a multimode interference structure (multiple-mode interference, MMI) to split the high/high power input signal light and the pump light, and changes the positions of the partially split signal light and pump light by regulating the cross state of the optical switch, so as to form cross arrangement of the signal light and the pump light, so that the pump light is smoothly input into each waveguide amplifier for amplification, and the optimal gain of a small signal after splitting is realized, and then the beam combination is performed, thereby solving the problem that the gain of the amplifier directly input with large signal power is small, and improving the gain performance of the large signal power;

The on-chip wavelength-division multiplexing (WDM) structure is introduced, so that the beam combination/beam splitting of the signal light and the pump light can be realized on the chip, the core composition structure of the on-chip wavelength-division multiplexing structure can be realized on the basis of the chip, and the on-chip wavelength-division multiplexing structure comprises a multimode interference structure, an optical switch, a wavelength-division multiplexing structure and a doped waveguide amplifier, so that the on-chip integrated waveguide amplifier can be truly realized, the on-chip integrated waveguide amplifier can be directly combined with other structures on the chip, the integration level is high, and the application of a large-scale integrated photon loop is facilitated;

the method and the device avoid the problem of chip end surface damage and nonlinearity caused by overhigh chip input power in the integrated chip by carrying out beam splitting-multichannel amplification-beam combination on a large input signal.

Drawings

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

Fig. 1 schematically illustrates a schematic diagram of an on-chip integrated amplifier provided by an embodiment of the present disclosure.

Reference numerals illustrate:

1-a first input optical waveguide; 2-a second input optical waveguide; 3-a first multimode interference structure; 4-a second multimode interference structure; 5-optical switch; 6-a first wavelength division multiplexing structure; 7-a second wavelength division multiplexing structure; 8-a first waveguide amplifier; 9-a second waveguide amplifier; 10-a third wavelength division multiplexing structure; 11-a fourth wavelength division multiplexing structure; 12-a third multimode interference structure; 13-output optical waveguide.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. It should be understood that the description is only exemplary and is not intended to limit the scope of the present disclosure. In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. It may be evident, however, that one or more embodiments may be practiced without these specific details. In addition, in the following description, descriptions of well-known structures and techniques are omitted so as not to unnecessarily obscure the concepts of the present disclosure.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The terms "comprises," "comprising," and/or the like, as used herein, specify the presence of stated features, steps, operations, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, or components.

All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be construed to have meanings consistent with the context of the present specification and should not be construed in an idealized or overly formal manner.

Some of the block diagrams and/or flowchart illustrations are shown in the figures. It will be understood that some blocks of the block diagrams and/or flowchart illustrations, or combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the instructions, when executed by the processor, create means for implementing the functions/acts specified in the block diagrams and/or flowchart.

In the prior art, the gain of the waveguide amplifier is affected by the input signal optical power, and the larger the input signal optical power is, the smaller the signal gain is, because the increase of the signal optical power can cause the increase of the non-radiative recombination probability, the increase of noise, and the conversion efficiency of stimulated radiation amplification is reduced. Based on this problem, the present disclosure proposes a structure of a high-gain on-chip integrated amplifier for high signal power input.

As shown in fig. 1, an embodiment of the present disclosure provides an on-chip integrated amplifier, comprising: a first input optical waveguide 1, a second input optical waveguide 2, a first multimode interference structure 3, a second multimode interference structure 4, an optical switch 5, a first wavelength division multiplexing structure 6, a second wavelength division multiplexing structure 7, a first waveguide amplifier 8, a second waveguide amplifier 9, a third wavelength division multiplexing structure 10, a fourth wavelength division multiplexing structure 11, a third multimode interference structure 12 and an output optical waveguide 13.

In the embodiment of the present disclosure, the first input optical waveguide 1 is used for inputting signal light; the second input optical waveguide 2 is used for inputting pump light; the first multimode interference structure 3 is connected with the first input optical waveguide 1 and is used for dividing signal light into two beams according to a first optical power ratio; the second multimode interference structure 4 is connected with the second input optical waveguide 2 and is used for dividing the pump light into two beams according to a second optical power ratio; two input ports of the optical switch 5 are respectively connected with one path of output of the first multimode interference structure 3 and one path of output of the second multimode interference structure 4, and the two output ports are used for carrying out position exchange on one path of signal light output by the first multimode interference structure 3 and one path of pump light output by the second multimode interference structure 4; the two input ports of the first wavelength division multiplexing structure 6 are used for inputting another path of signal light output by the first multimode interference structure 3 and one path of pump light output by the optical switch 5, and for coupling the other path of signal light and one path of pump light; the two input ports of the second wavelength division multiplexing structure 7 are used for inputting another pump light output by the second multimode interference structure 4 and one signal light output by the optical switch 5, and for coupling the other pump light and one signal light; the first waveguide amplifier 8 and the second waveguide amplifier 9 are respectively connected with the first wavelength division multiplexing structure 6 and the second wavelength division multiplexing structure 7 and are used for amplifying signal light in the coupled light output by the first waveguide amplifier 8 and the second waveguide amplifier 9; the third wavelength division multiplexing structure 10 and the fourth wavelength division multiplexing structure 11 are respectively connected with the first waveguide amplifier 8 and the second waveguide amplifier 9 and are used for separating amplified signal light from pump light; the third multimode interference structure 12 connects the third wavelength division multiplexing structure 10 and the fourth wavelength division multiplexing structure 11 for combining the signals into a beam.

The on-chip integrated amplifier provided by the disclosure utilizes MMI to split the high/high power input signal light and the pump light, and the positions of the signal light and the pump light are exchanged by the optical switch 5 unit are regulated so as to smoothly input the pump light into each waveguide amplifier, so that the optimal gain of the small signals after splitting is realized, and then the beam combination is performed, the problem that the gain of the amplifier is small when the high signal power is directly input is solved, and the gain performance of the high signal power is improved.

The first input optical waveguide 1 and the second input optical waveguide 2 are straight waveguides. Typically, the signal light is in the C-band and pump light having a wavelength of 980nm or 1480nm is used.

The first multimode interference structure 3 and the second multimode interference structure 4 are 1×2mmi, and are used for splitting signal light/pump light, and splitting higher-power signal light/pump light into multiple beams of lower-power signal light/pump light, so as to realize the optimal gain of a small signal. Considering that the paths of the signal light and the pump light entering the different doped waveguide amplifiers are different, preferably, the optical power ratio of the two output ends of the 1 x 2mmi is not equal to 1, and one path of signal light entering the optical switch 5 at the back should occupy larger optical power than the other path of signal light not entering the optical switch 5, and the optical power of one path of pump light output to the optical switch 5 is larger than the other Lu Bengpu light so as to balance the amplification gain of each channel. The third multimode interference structure 12 is a2×1mmi, and is configured to combine and output the signal light amplified by the different waveguide amplifiers.

The 2 x 2 optical switch 5 is in a Mach-Zehnder type or micro-ring structure and is in a crossed state, the two input ends respectively correspond to one path of signal light and pump light after beam splitting, and the positions of the two beams of light are exchanged through the crossed state of the optical switch 5, so that the signal light and the pump light are smoothly input into each waveguide amplifier, and multichannel (n is more than or equal to 2) amplification is realized.

The first wavelength division multiplexing structure 6 and the second wavelength division multiplexing structure 7 are used for coupling the signal light and the pump light after beam splitting into the same waveguide, and transmitting the signal light and the pump light into an input port of the waveguide amplifier for amplifying the signal light. The third wavelength division multiplexing structure 10 and the fourth wavelength division multiplexing structure 11 are used for separating the signal light amplified by the waveguide amplifier from the pump light according to the self-mapping principle, and performing beam combination of the signal light amplified by each subsequent channel. The first wavelength division multiplexing structure 6, the second wavelength division multiplexing structure 7, the third wavelength division multiplexing structure 10 and the fourth wavelength division multiplexing structure 11 are inclined multimode interferometers or multimode waveguide grating structures.

The first waveguide amplifier 8 and the second waveguide amplifier 9 are helical ridge waveguide amplifiers doped with rare earth ions. The material of the optical waveguide should be selected to have a large electro-optic effect, and preferably, lithium niobate or a polymer material having a large electro-optic coefficient is used. The doping ions of the first waveguide amplifier 8 and the second waveguide amplifier 9 are materials with an amplification band of C-band. The ion may be preferably a bait ion or a bait ion co-doped with other ions, and specifically, a bait ion co-doped with ytterbium ion. The first waveguide amplifier 8 and the second waveguide amplifier 9 are used for amplifying the signal light with the small power of multiple paths (n is more than or equal to 2) after splitting, and combining the amplified signal light after realizing the optimal gain of the small signal, so that the problem that the gain of the single waveguide amplifier is poor when the power of the large input signal is directly input is solved. The first waveguide amplifier 8 and the second waveguide amplifier 9 have different waveguide lengths to compensate for a phase difference of each signal light due to an optical path difference.

In some embodiments of the present disclosure, the high-gain on-chip integrated amplifier for high-signal power input introduces a structure of an MMI combined optical switch 5, splits an input high-power signal light and a pump light by the MMI, and changes the positions of the partially split signal light and pump light by adjusting and controlling the crossing state of the optical switch 5 to form crossing arrangement of the signal light and pump light, so that each path of signal light and pump light can be smoothly input into a corresponding doped waveguide amplifier for amplification, and after the optimal gain is achieved, the split multipath small signals are combined by the MMI to achieve high-gain amplification of the high-power signal;

In some embodiments of the present disclosure, the on-chip wavelength division multiplexing structure may realize beam combination/splitting of signal light and pump light on a chip, and its core component structures may be realized based on the chip, including 1×2mmi, 2×2optical switch 5, WDM and doped waveguide amplifier, so as to realize an on-chip integrated waveguide amplifier in a true sense, and may be directly combined with other structures on the chip for use, so that the integration level is high, and the application of a large-scale integrated photonic circuit is facilitated;

in some embodiments of the present disclosure, the above-described structure avoids the problem of chip end-face damage and nonlinearity caused by excessive chip input power in an integrated chip by "splitting-multichannel amplifying-combining" large input signals.

Those skilled in the art will appreciate that the features recited in the various embodiments of the disclosure and/or in the claims may be provided in a variety of combinations and/or combinations, even if such combinations or combinations are not explicitly recited in the disclosure. In particular, the features recited in the various embodiments of the present disclosure and/or the claims may be variously combined and/or combined without departing from the spirit and teachings of the present disclosure. All such combinations and/or combinations fall within the scope of the present disclosure.

While the present disclosure has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents. The scope of the disclosure should, therefore, not be limited to the above-described embodiments, but should be determined not only by the following claims, but also by the equivalents of the following claims.

Claims (10)

1. An on-chip integrated amplifier, comprising:

a first input optical waveguide (1) for inputting signal light;

A second input optical waveguide (2) for inputting pump light;

a first multimode interference structure (3) connected to the first input optical waveguide (1) for splitting the signal light into two beams according to a first optical power ratio;

A second multimode interference structure (4) connected to the second input optical waveguide (2) for splitting the pump light into two beams according to a second optical power ratio;

The optical switch (5) is respectively connected with one path of output of the first multimode interference structure (3) and one path of output of the second multimode interference structure (4) through two input ports, and the two output ports are used for carrying out position exchange on one path of signal light output by the first multimode interference structure (3) and one path of pump light output by the second multimode interference structure (4);

the first wavelength division multiplexing structure (6) is used for inputting another path of signal light output by the first multimode interference structure (3) and one path of pump light output by the optical switch (5) through two input ports, and is used for coupling the other path of signal light and the one path of pump light;

the second wavelength division multiplexing structure (7) is used for inputting another path of pump light output by the second multimode interference structure (4) and one path of signal light output by the optical switch (5) through two input ports, and for coupling the other Lu Bengpu light and the one path of signal light;

a first waveguide amplifier (8) and a second waveguide amplifier (9) respectively connected with the first wavelength division multiplexing structure (6) and the second wavelength division multiplexing structure (7) and used for amplifying signal light in coupled light output by the first waveguide amplifier (8) and the second waveguide amplifier (9);

A third wavelength division multiplexing structure (10) and a fourth wavelength division multiplexing structure (11) respectively connected with the first waveguide amplifier (8) and the second waveguide amplifier (9) and used for separating the amplified signal light from the pump light;

-a third multimode interference structure (12) connecting said third wavelength division multiplexing structure (10) and said fourth wavelength division multiplexing structure (11) for combining said signals into a beam.

2. An on-chip integrated amplifier according to claim 1, characterized in that the waveguide lengths of the first waveguide amplifier (8) and the second waveguide amplifier (9) are different to compensate for the phase difference of the signal light of each path.

3. The on-chip integrated amplifier according to claim 1, wherein an optical power of one of the signal lights output to the optical switch (5) is larger than that of the other of the signal lights, and an optical power of one of the pump lights output to the optical switch (5) is larger than that of the other of the pump lights.

4. An on-chip integrated amplifier according to claim 1, characterized in that the first input optical waveguide (1) and the second input optical waveguide (2) are straight waveguides.

5. The integrated on-chip amplifier according to claim 1, characterized in that the first wavelength division multiplexing structure (6), the second wavelength division multiplexing structure (7), the third wavelength division multiplexing structure (10) and the fourth wavelength division multiplexing structure (11) are tilted multimode interferometers or multimode waveguide grating structures.

6. An on-chip integrated amplifier according to claim 1, characterized in that the optical switch (5) is of the mach-zehnder type or of the micro-ring type.

7. The on-chip integrated amplifier according to claim 1, characterized in that the first waveguide amplifier (8) and the second waveguide amplifier (9) are rare earth ion doped helical ridge waveguide amplifiers.

8. The on-chip integrated amplifier according to claim 7, characterized in that the doping ions of the first waveguide amplifier (8) and the second waveguide amplifier (9) are materials with an amplification band of C-band.

9. The integrated amplifier on chip of claim 8, wherein the dopant ions are erbium ions or a combination of erbium ions and erbium ions.

10. The integrated on-chip amplifier of claim 1, wherein the signal light is in the C-band and the pump light wavelength is 980nm or 1480nm.