Hybrid integrated photon analog-to-digital conversion chip

Abstract

The invention relates to a hybrid integrated photon analog-to-digital conversion chip, and belongs to the technical field of integrated circuits. The chip is divided into a photon front end and an electronic rear end from left to right, the photon front end is composed of an optical clock generation function unit and an electro-optical sampling function unit, and the electronic rear end is composed of a multi-channel high-precision electric ADC. According to the invention, the generation of an optical frequency comb is realized through the hybrid integration of the III-V active DFB laser and the silicon nitride high-quality factor micro-ring, an optical clock function in a photon front end is formed, and the integration of an electro-optical modulator, a high-speed optical switch, a delay line and a photoelectric detector is realized based on a silicon-on-insulator and germanium heterogeneous integration platform. And an electro-optical sampling function in the photon front end is formed. According to the design, the bottleneck that an electronic ADC is limited by bandwidth and time jitter can be effectively broken through, and the precision and speed of analog-to-digital conversion are improved. By combining the advantages of ultra-large bandwidth and high integration level of the integrated photonic device, the speed and precision of the analog-to-digital conversion chip can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of integrated circuits and relates to a hybrid integrated photonic analog-to-digital conversion chip. Background Art

[0002] Analog-to-digital converters are the bridge between the digital world and the physical world and have long been widely used. The current electronic analog-to-digital converters based on electronic technology are limited by bandwidth and time jitter bottlenecks, and have reached their limits in key performance indicators such as input bandwidth, sampling rate and quantization accuracy, so further improvement has become quite challenging. Photonic digital-to-analog conversion combined with ultra-large bandwidth and high-stability clock is a very promising technical route. Based on photonic analog-to-digital conversion technology, combined with the advantages of photonic technology in bandwidth, rate and noise level, photonic devices and electronic analog-to-digital converters can be successfully combined, and the expansion of analog-to-digital conversion technology is achieved through a new architecture, so that it has a larger input bandwidth, higher sampling rate and higher digital quantization accuracy. However, the current photonic analog-to-digital conversion technology is mostly composed of discrete devices such as fiber optical frequency combs and lithium niobate modulators, which face the problems of large size and power consumption, poor consistency, low bandwidth and time jitter.

[0003] Therefore, there is an urgent need to design a hybrid integrated photonic analog-to-digital conversion chip that integrates high-performance photonic devices and electronic devices to achieve an integrated photonic analog-to-digital conversion chip, reduce size, power consumption and time jitter, and improve sampling rate and digital quantization accuracy. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a hybrid integrated photonic analog-to-digital conversion chip to solve the problems of large size, low speed and instability of existing similar systems. In the photonic front end, the optical clock generation part adopts DFB and high quality factor micro-ring feedback injection locking to realize high-quality optical frequency comb, and is hybrid integrated with the electro-optical sampling part, electrical ADC and DSP part. This design can significantly improve the sampling rate of the photonic analog-to-digital conversion chip and reduce time jitter. Through the hybrid integration of photonic devices and electronic devices, the advantage of the large bandwidth of photonic devices is fully utilized. The present invention effectively improves the analog-to-digital conversion sampling rate, significantly reduces the system size and power consumption compared with traditional solutions, shortens the signal interconnection distance, enhances chip synchronization, and greatly reduces time jitter.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] Hybrid integrated photonic analog-to-digital conversion chip, including:

[0007] At least one photon front end, the photon front end comprising:

[0008] at least one laser for generating a laser signal;

[0009] at least one photon frequency comb generating unit, connected to the laser, for generating a photon frequency comb;

[0010] at least one optical switch array, connected to the photon frequency comb generating unit, for splitting the photon frequency comb into a plurality of channels;

[0011] At least one photodetector array, connected to the optical switch array, for converting photon signals into electrical signals;

[0012] At least one electronic backend, the electronic backend comprising:

[0013] at least one electrical analog-to-digital converter array, connected to the photodetector array, for converting electrical signals into digital signals;

[0014] at least one digital signal processor connected to the electrical analog-to-digital converter array and configured to process the digital signal;

[0015] Wherein, the photonic front end and the electronic back end are integrated on the same chip.

[0016] Furthermore, the photon frequency comb generating unit comprises at least one distributed feedback laser DFB and at least one high quality factor microring resonator, and the DFB and the microring resonator realize the generation of the photon frequency comb through self-injection locking.

[0017] Furthermore, the optical switch array includes at least three high-speed optical switches for splitting the photon frequency comb into four channels.

[0018] Furthermore, the bandwidth of the photodetector array is greater than or equal to 10 GHz.

[0019] Furthermore, the electrical analog-to-digital converter array includes at least four electrical analog-to-digital converters for converting electrical signals into digital signals.

[0020] Furthermore, the digital signal processor is used to perform interleaving processing on the digital signals output by the electrical analog-to-digital converter array.

[0021] Furthermore, the sampling rate of the hybrid integrated photonic analog-to-digital conversion chip is greater than or equal to 20 GHz.

[0022] The beneficial effects of the present invention are: by adopting the hybrid integration of multiple photonic devices and electronic devices, the advantages of large bandwidth of photonic devices and short interconnection distance of hybrid integration are fully utilized to realize effective frequency division and recombination of large bandwidth. This design can effectively improve the analog-to-digital conversion sampling rate, significantly reduce the system size and power consumption, shorten the signal interconnection distance, enhance chip synchronization, and greatly reduce time jitter.

[0023] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 This is a schematic diagram of the architecture of the hybrid integrated photonic analog-to-digital conversion chip of the present invention;

[0026] Figure 2 Another embodiment of the present invention is a schematic diagram of a hybrid integrated photonic analog-to-digital conversion chip architecture with two channels interleaved;

[0027] Reference numerals: 101 - DFB laser of embodiment 1, 102 - silicon nitride microring of embodiment 1, 103 - electro-optic modulator of embodiment 1, 104 - first high-speed optical switch of embodiment 1, 105 - second high-speed optical switch of embodiment 1, 106 - third high-speed optical switch of embodiment 1, 107 - detector array of embodiment 1, 108 - electrical ADC array of embodiment 1, 109 - DSP processing unit of embodiment 1;

[0028] 201 - DFB laser of embodiment 2, 202 - silicon nitride microring of embodiment 2, 203 - electro-optic modulator of embodiment 2, 204 - high-speed optical switch of embodiment 2, 205 - detector array of embodiment 2, 206 - electrical ADC array of embodiment 2, 207 - DSP processing unit of embodiment 2. DETAILED DESCRIPTION

[0029] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0030] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0031] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0032] Example 1

[0033] See also Figure 1 ,like Figure 1 As shown, an embodiment of the present invention provides a hybrid integrated photonic analog-to-digital conversion chip, which includes, from left to right, a DFB laser 101 of embodiment 1, a silicon nitride microring 102 of embodiment 1, an electro-optic modulator 103 of embodiment 1, a first high-speed optical switch 104 of embodiment 1, a second high-speed optical switch 105 of embodiment 1, a third high-speed optical switch 106 of embodiment 1, a detector array 107 of embodiment 1, an electrical ADC array 108 of embodiment 1, and a DSP processing unit 109 of embodiment 1.

[0034] Among them, the DFB laser 101 of the first embodiment is a III-V compound semiconductor device; the silicon nitride microring 102 of the first embodiment is a silicon nitride device; the electro-optic modulator 103 of the first embodiment, the first high-speed optical switch 104 of the first embodiment, the second high-speed optical switch 105 of the first embodiment and the third high-speed optical switch 106 of the first embodiment, and the detector array 107 of the first embodiment are silicon-on-insulator and germanium platform devices; the electrical ADC array 108 of the first embodiment and the DSP processing unit 109 of the first embodiment are electronic devices, and the photon digital-to-analog conversion chip is realized through a hybrid integrated architecture.

[0035] In this embodiment, the signal interleaving number is 4, the optical clock repetition frequency achieved by self-injection locking of the DFB laser 101 in the first embodiment and the silicon nitride microring 102 in the first embodiment is 40 GHz, the first high-speed optical switch 104 in the first embodiment, the second high-speed optical switch 105 in the first embodiment and the third high-speed optical switch 106 in the first embodiment are branched into 4 channels, which respectively enter a 4-channel photodetector array with a bandwidth greater than or equal to 10 GHz for photoelectric conversion, and then enter a 4-channel ADC array for analog-to-digital conversion, and finally the synthesized signal is processed by the DSP.

[0036] The chip of this embodiment adopts the hybrid integration of multiple photonic devices and electronic devices through the present invention, fully utilizing the advantages of large bandwidth of photonic devices and short interconnection distance of hybrid integration, and realizes effective frequency division and recombination of large bandwidth. This design can effectively improve the analog-to-digital conversion sampling rate, significantly reduce system size and power consumption, shorten the signal interconnection distance, enhance chip synchronization, and significantly reduce time jitter.

[0037] Example 2

[0038] like Figure 2 As shown, another embodiment of the present invention provides a hybrid integrated photonic analog-to-digital conversion chip, including a second embodiment DFB laser 201, a second embodiment silicon nitride microring 202, a second embodiment electro-optical modulator 203, a second embodiment high-speed optical switch 204, a second embodiment detector array 205, a second embodiment electrical ADC array 206 and a second embodiment DSP processing unit 207. In the second embodiment, the signal interleaving number is 2, the optical clock repetition frequency achieved by the self-injection locking of the second embodiment DFB laser 201 and the second embodiment silicon nitride microring 202 is 20 GHz, and the second embodiment high-speed optical switch 204 is divided into 2 channels, which respectively enter a 2-channel photodetector array with a bandwidth greater than or equal to 10 GHz for photoelectric conversion, and then enter a 2-channel electrical ADC array for analog-to-digital conversion, and finally the synthesized signal is processed by the DSP.

[0039] The chip in Example 2 can achieve a photon digital-to-analog sampling rate of 20 GHz, while Example 1 can achieve a photon digital-to-analog sampling rate of 40 GHz, the upper limit of which is subject to the free spectral range of the optical frequency comb generated by the DFB laser and silicon nitride microring self-injection locking, as well as the scale of the supporting optical switch array, detector array and electrical ADC array.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. Hybrid integrated photonic analog-to-digital conversion chip, characterized in that: include: At least one photon front end, the photon front end comprising: at least one laser for generating a laser signal; at least one photon frequency comb generating unit, connected to the laser, for generating a photon frequency comb; at least one optical switch array, connected to the photon frequency comb generating unit, for splitting the photon frequency comb into a plurality of channels; At least one photodetector array, connected to the optical switch array, for converting photon signals into electrical signals; At least one electronic backend, the electronic backend comprising: at least one electrical analog-to-digital converter array, connected to the photodetector array, for converting electrical signals into digital signals; at least one digital signal processor connected to the electrical analog-to-digital converter array and configured to process the digital signal; Wherein, the photonic front end and the electronic back end are integrated on the same chip.

2. The hybrid integrated photonic analog-to-digital conversion chip according to claim 1, characterized in that: The photon frequency comb generating unit comprises at least one distributed feedback laser DFB and at least one high quality factor micro-ring resonator, and the DFB and the micro-ring resonator realize the generation of the photon frequency comb through self-injection locking.

3. The hybrid integrated photonic analog-to-digital conversion chip according to claim 1, characterized in that: The optical switch array includes at least three high-speed optical switches for splitting the photon frequency comb into four channels.

4. The hybrid integrated photonic analog-to-digital conversion chip according to claim 1, characterized in that: The bandwidth of the photodetector array is greater than or equal to 10 GHz.

5. The hybrid integrated photonic analog-to-digital conversion chip according to claim 1, characterized in that: The electrical analog-to-digital converter array includes at least four electrical analog-to-digital converters for converting electrical signals into digital signals.

6. The hybrid integrated photonic analog-to-digital conversion chip according to claim 1, characterized in that: The digital signal processor is used for interleaving the digital signals output by the electrical analog-to-digital converter array.

7. The hybrid integrated photonic analog-to-digital conversion chip according to claim 1, characterized in that: The sampling rate of the hybrid integrated photonic analog-to-digital conversion chip is greater than or equal to 20 GHz.

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