Photoelectric hybrid integrated time delay device with nested structure

Abstract

The invention discloses a photoelectric hybrid integrated time-delay device with a nested structure, which comprises a group of electric time-delay devices consisting of radio frequency switches and a set of optical time-delay devices nested in the electric time-delay devices, and the optical time-delay devices comprise a laser, a plurality of optical switches and a detector which are connected in sequence. According to the invention, electric time delay and optical time delay are perfectly combined, ultra-short initial time delay amount (0.1 ns level) and ultra-long time delay amount (more than dozens of microseconds) are ensured at the same time, the advantages of high switching speed, randomly adjustable time delay stepping, randomly adjustable time delay amount, low cost, convenience in maintenance, high expandability, good adaptability and the like of the original photoelectric time delay are retained, and the photoelectric time delay has a wide application prospect.

Description

Technical Field

[0001] The invention relates to the technical field of optical communications, and in particular to a photoelectric hybrid integrated delay device with a nested structure. Background Art

[0002] Delay technology is a technology that delays signals by changing the length of the path that the signal travels. In information technology, delay technology plays a very important role. For example, in communication systems, delay technology can be used to achieve time division multiplexing and demultiplexing of signals; in optical switching networks, delay technology can be used to solve packet competition problems; in areas such as live video broadcasting and precision guidance, delay technology support is also needed.

[0003] Usually, the optical delay device needs to convert the electrical signal into an optical signal first, and adjust the path length of the optical signal to the required range through the switching of a series of optical switches. After the delay control is completed, the optical signal is restored to an electrical signal. Because of the characteristics of optical fiber such as light weight, small size, and large optical signal bandwidth, optical delay usually has the advantages of long delay, small size, fast switching speed, large bandwidth, and precise control. However, since the fiber fusion splicer has a limit on the shortest length of the fusion fiber, each additional optical switch will increase the delay by about several ns, plus two photoelectric conversions, resulting in the shortest delay of the traditional optical delay device, that is, the starting delay is generally more than a dozen ns.

[0004] However, electric delay devices are difficult to achieve long-distance delay due to the large cable loss, thick diameter and heavy weight. In addition, as the signal frequency increases, various problems such as insufficient bandwidth and signal distortion will arise.

[0005] The existing optoelectronic hybrid delay device is a series structure. For example, the Chinese invention patent application with publication number CN109905140A records a radio frequency signal delay system, including: an electro-optical conversion module, which is used to modulate the radio frequency signal to be delayed onto an optical carrier to obtain an optical carrier signal; an optical delay module, which is used to make the optical carrier signal obtain an optical delay; an electrical delay module, which is used to demodulate the radio frequency signal from the optical carrier signal that has undergone optical delay, and make the demodulated radio frequency signal obtain an electrical delay. The present invention realizes fine delays of different orders of magnitude through the combination of optical delay and electrical delay, and finally realizes a continuous large-range finely adjustable phase-stable optoelectronic hybrid radio frequency delay system with a delay of the order of μs and a tuning accuracy of the order of ns. The above scheme cannot simultaneously meet the requirements of ultra-short starting delay (0.1ns level) and ultra-long delay (tens of μs level). Summary of the invention

[0006] The present invention proposes a nested optoelectronic hybrid integrated delay device, which nests electrical delay and optical delay, and has both an ultra-short initial delay (0.1ns level) and an ultra-long delay (more than tens of μs).

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A nested optoelectronic hybrid integrated delay device includes a set of electric delay devices composed of radio frequency switches and a set of optical delay devices nested inside the electric delay devices. The optical delay device includes a laser, multiple optical switches and detectors connected in sequence.

[0009] Preferably, the electric delay device comprises a first 1×N radio frequency switch, an N×N radio frequency switch and a second 1×N radio frequency switch which are sequentially cascaded, and N is a natural number not less than 2;

[0010] The input port of the first 1×N RF switch is the input port of the entire delay device, and the N output ports of the first 1×N RF switch are sequentially connected to the N input ports of the N×N RF switch;

[0011] The N-1 output ports of the N×N RF switch are sequentially connected to the N-1 input ports of the second 1×N RF switch, the Nth output port of the N×N RF switch is connected to the laser RF input port of the optical delay device, and the Nth input port of the second 1×N RF switch is connected to the detector RF output port of the optical delay device;

[0012] The output port of the second 1×N radio frequency switch is the output port of the entire delay device.

[0013] Preferably, according to the actual development situation of existing radio frequency switches, N is 2 m , where m is a natural number, such as N is generally a natural number such as 2, 4, 8, 16, etc. Most preferably, N is 4 or 8, that is, m is 2 or 3.

[0014] Preferably, the optical delay device comprises a laser connected in sequence, a first 1×S optical switch, a group of S×S optical switches and a second 1×S optical switch connected in sequence with the same structure, and a detector connected behind the second 1×S optical switch. Wherein, S is the number of input / output ports of the 1×S and S×S optical switches, and S is a positive integer not less than 2. More preferably, S is 2 f, where f is a natural number; for example, the optical switches can be 1×2, 2×2, 1×4, 4×4, 1×8, 8×8, etc. The number of S×S optical switches is represented by Z, which is a natural number not less than 0. Considering the actual development of existing optical switches, including but not limited to price, maturity, user needs, system complexity, maintainability, etc., it is most preferred to use 2 1×2 optical switches and Z 2×2 optical switches.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The present invention embeds the optical delay device in the electrical delay device to achieve a perfect combination of the two, which has both an ultra-short starting delay (0.1ns level) and an ultra-long delay (more than tens of μs); and retains the advantages of the original photoelectric delay device, such as fast switching speed, arbitrarily adjustable delay step, arbitrarily adjustable delay amount, low cost, easy maintenance, strong scalability, good adaptability, etc., and has good and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of using 1×4 and 4×4 radio frequency switches with 1×2 and 2×2 optical switches in Example 1 when N=4;

[0019] Figure 3 This is a schematic diagram of the structure of Example 2 where N=8, i.e., using 1×8 and 8×8 RF switches in combination with 1×2 and 2×2 optical switches. DETAILED DESCRIPTION

[0020] In order to make the purpose and advantages of the present invention more clear, the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0021] like Figure 1 As shown, the present invention discloses a nested optoelectronic hybrid integrated delay device, including a set of electric delay devices composed of radio frequency switches, and a set of optical delay devices nested inside the electric delay devices, wherein the optical delay device includes a laser, multiple optical switches and detectors connected in sequence.

[0022] The electric delay device includes a first 1×N RF switch, an N×N RF switch and a second 1×N RF switch which are cascaded in sequence, where N is a natural number not less than 2; the input port of the first 1×N RF switch is the input port of the entire delay device, and the N output ports of the first 1×N RF switch are connected in sequence to the N input ports of the N×N RF switch; the N-1 output port of the N×N RF switch is connected in sequence to the N-1 input port of the second 1×N RF switch, the Nth output port of the N×N RF switch is connected to the laser RF input end of the optical delay device, and the Nth input port of the second 1×N RF switch is connected to the detector RF output end of the optical delay device; the output port of the second 1×N RF switch is the output port of the entire delay device.

[0023] The optical delay device comprises a sequentially connected laser, a first 1×S optical switch, a group of sequentially cascaded S×S optical switches and a second 1×S optical switch with the same structure, and a detector connected behind the second 1×S optical switch. Wherein, S is the number of input / output ports of the 1×S and S×S optical switches, and S is a positive integer not less than 2.

[0024] In practical applications, the delay amount and delay step need to be set, which can be designed within the scope of the present invention. The following is a detailed description using 1×4 and 4×4 RF switches with 1×2 and 2×2 optical switches (Example 1), and 1×8 and 8×8 RF switches with 1×2 and 2×2 optical switches (Example 2).

[0025] Embodiment 1:

[0026] Reference Figure 2 , suppose that 1×4 and 4×4 RF switches need to be used in combination with 1×2 and 2×2 optical switches to achieve an initial delay of no more than 2ns, a step of 3ns, and a maximum delay of no less than 24μs. At this time, a total of 2 1×4 RF switches, 1 4×4 RF switch, 1 laser, 1 detector, 2 1×2 optical switches, and 10 2×2 optical switches need to be connected in sequence to achieve this. The RF cables connecting the first output port of the first 1×4 RF switch and the first input port of the 4×4 RF switch; the first output port of the 4×4 RF switch and the first input port of the second 1×4 RF switch, as well as the input port of the first 1×4 RF switch and the output port of the second 1×4 RF switch and the structural housing should be as short as possible. The total length of these 4 sections of RF cables plus the connectors shall not exceed 48cm (it is known that the length of the RF cable that produces a 1ns delay is about 24cm. This value may be slightly different for delay cables from different manufacturers. Actual measurement is required when the delay accuracy is required to be accurate to 0.xns). The average total length of each section of RF cable including the connector does not exceed 12cm, which is completely feasible in engineering.

[0027] Assume that the length of the RF cable between the first output port of the first 1×4 RF switch and the first input port of the 4×4 RF switch is t0 (the theoretical value is 0, but it is impossible to be 0 in practice), and the length of the RF cable between the first output port of the 4×4 RF switch and the first input port of the second 1×4 RF switch is k0 (the theoretical value is 0, but it is impossible to be 0 in practice); at this time, the length of the RF cable between the second output port of the first 1×4 RF switch and the second input port of the 4×4 RF switch should be: X×3ns×24cm / ns+t0 (unit: cm), where X is the order of the electric delay device, and at this time X is 1, that is, 1×3ns×24cm / ns+ t0 (unit: cm); the length of the RF cable between the third output port of the first 1×4 RF switch and the third input port of the 4×4 RF switch is: X×3ns×24cm / ns+t0 (unit: cm), where X is the number of stages of the electric delay device, and X is 2 at this time, i.e., 2×3ns×24cm / ns+t0 (unit: cm); the length of the RF cable between the fourth output port of the first 1×4 RF switch and the fourth input port of the 4×4 RF switch is: X×3ns×24cm / ns+t0 (unit: cm), where X is the number of stages of the electric delay device, and X is 3 at this time, i.e., 3×3ns×24cm / ns+t0 (unit: cm). The length of the RF cable between the second output port of the 4×4 RF switch and the second input port of the second 1×4 RF switch is: X×3ns×24cm / ns+k0 (in cm), where X is the number of stages of the electric delay device, and X is 4, i.e., 4×3ns×24cm / ns+k0 (in cm); the length of the RF cable between the third output port of the 4×4 RF switch and the third input port of the second 1×4 RF switch is: X×3ns×24cm / ns+k0 (in cm), where X is the number of stages of the electric delay device, and X is 8, i.e., 8×3ns×24cm / ns+k0 (in cm). The setting rules of the number of stages X of the electric delay device (also the number of stages X of the RF cable) are prior art and have been disclosed, such as A in the Chinese invention patent with publication number CN 113376753A. iN , which will not be elaborated in detail here, corresponding to Figure 2 The numbers indicated on the solid lines with arrows (solid lines with arrows represent RF cables for connection).

[0028] At this time, the shortest delay that the optical delay device needs to provide is (12×3+k0 / 24)ns=(36×24+k0)cm. Similarly, the first input / output port of the optical switch should all use the shortest connection to ensure that the initial amount of optical delay meets (36+k0 / 24)ns. Figure 2The shortest connection should be used between the input and output ports of each optical switch in the optical delay device (the dashed line with an arrow but no number in the figure). Theoretically, it is hoped that it is 0, but it is actually impossible to achieve. However, it should be ensured that the shortest connection is from the 4th output port of the RF 4×4 to the RF input port of the laser, and then from the laser output fiber to the input port of the first 1×2 optical switch, and then from the first output port of the first 1×2 optical switch to the first input port of the first 2×2 optical switch, and then from the first output port of the first 2×2 optical switch to the second 2×2 optical switch. The first input port of the switch, then the first output port of the second 2×2 optical switch to the first input port of the third 2×2 optical switch, and so on, until the first output port of the tenth 2×2 optical switch is connected to the first input port of the second 1×2 optical switch, the output port of the second 1×2 optical switch to the detector input pigtail, and then from the detector RF output to the fourth input port of the second 1×4 RF switch, the delay caused by all RF cables and optical fibers meets (36+k0 / 24)ns. This is feasible in engineering.

[0029] The length of each section of optical fiber between the second output port of the first 1×2 optical switch to the second input port of the first 2×2 optical switch, the second output port of the first 2×2 optical switch to the second input port of the second 2×2 optical switch, the second output port of the second 2×2 optical switch to the second input port of the third 2×2 optical switch, and so on until the second output port of the tenth 2×2 optical switch and the second input port of the second 1×2 optical switch should be controlled to be longer than the delay caused by the optical fiber between their corresponding first output / input ports (4×2 M ×3)ns, M is a natural number from 0 to 10. M is the series Y corresponding to the segment, that is, the numbers on the line segments in the figure, which are 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048 and 4096 respectively. To convert it into delay, it should be multiplied by the step of 3ns, that is, 12ns, 24ns, 48ns, 96ns, 192ns, 384ns, 768ns, 1536ns, 3072ns, 6144ns, 12288ns respectively. Then multiply it by 20.4cm / ns to calculate the specific fiber length. At this time, press Figure 2 The optoelectronic hybrid integrated delay device of the nested structure shown can achieve a delay range from 2ns to 24μs, and can be adjusted in 3ns steps.

[0030] Embodiment 2:

[0031] Reference Figure 3, suppose that 1×8 and 8×8 RF switches need to be used with 1×2 and 2×2 optical switches to achieve an initial delay of no more than 3ns, a step of 2ns, and a maximum delay of no less than 15μs. At this time, a total of 2 1×8 RF switches, 1 8×8 RF switch, 1 laser, 1 detector, 2 1×2 optical switches, and 9 2×2 optical switches are required to be connected in sequence. And make the 1st output port of the first 1×8 RF switch and the 1st input port of the 8×8 RF switch; the 1st output port of the 8×8 RF switch and the 1st input port of the second 1×8 RF switch, as well as the input port of the first 1×8 RF switch and the output port of the second 1×8 RF switch and the structural shell as short as possible. The total length of these 4 sections of RF cables plus connectors should not exceed 72cm, and the average total length of each section of RF cable including connectors should not exceed 18cm (of course, RF devices such as isolators, low noise amplifiers, attenuators, etc. can also be added to the structure as needed, as long as the total delay generated by the connection between the devices does not exceed 3ns).

[0032] Assuming that the length of the RF cable between the first output port of the first 1×8 RF switch and the first input port of the 8×8 RF switch is t0, and the length of the RF cable between the first output port of the 8×8 RF switch and the first input port of the second 1×8 RF switch is k0, the order X of the RF cables between the second to eighth output ports of the first 1×8 RF switch and the second to eighth input ports of the 8×8 RF switch is 1, 2, 3, 4, 5, 6, 7, respectively, and the length of the RF cable is X×2ns×24cm / ns+t0 (in cm). The order X of the RF cable between the second to seventh output ports of the 8×8 RF switch and the second to seventh input ports of the second 1×8 RF switch is 8, 16, 24, 32, 40, 48, respectively, and the length of the RF cable is X×2ns×24cm / ns+k0 (in cm). An optical delay device is connected between the eighth output port of the 8×8 RF switch and the eighth input port of the second 1×8 RF switch. The shortest delay that this optical delay device needs to provide is 56×2ns. Similarly, the first input / output port of each optical switch in the optical delay device should all use the shortest connection to ensure that the initial amount of optical delay meets the requirements.

[0033] Because the optical delay device is embedded in the electrical delay device, Figure 3 After the electrical delay device is constructed using 1×8 and 8×8 RF switches, the step is 8, so the actual delay level Y of each section of the second input / output port of each optical switch in the optical delay device should be 8×2 M Settings, that is Figure 3 The numbers on the dashed lines with arrows and numbers below the optical switch in the delay device are 8, 16, 32, 64, 128, 256, 512, 1024, 2048, and 4096. Figure 3The nested optoelectronic hybrid integrated delay device shown can be adjusted between 3ns and 16μs in 2ns steps.

[0034] As shown in Example 1 and Example 2, the optoelectronic hybrid integrated delay device with a nested structure proposed by the present invention can perfectly combine electrical delay and optical delay, while ensuring an ultra-short starting delay (0.1ns level) (Note: the delay of the RF cable is 24cm / ns, and the starting delay of 0.1ns can be achieved with a length of 2.4cm for the RF line; so theoretically the starting delay can be a few tenths of a nanosecond, but engineering applications generally do not require delays starting from a few tenths of a nanosecond.), and an ultra-long delay (more than tens of μs), and retains the advantages of the original optoelectronic delay device, such as fast switching speed, arbitrarily adjustable delay step, arbitrarily adjustable delay, low cost, easy maintenance, strong scalability, good adaptability, etc., and has broad application prospects.

[0035] The above embodiments are only specific examples for further describing the purpose, technical solutions and beneficial effects of the present invention, and the present invention is not limited thereto. Any modification, equivalent replacement, improvement, etc. made within the scope of the disclosure of the present invention are included in the protection scope of the present invention.

Claims

1. A nested optoelectronic hybrid integrated delay device, characterized in that: It includes a set of electric delay devices composed of radio frequency switches and a set of optical delay devices nested inside the electric delay devices. The optical delay devices include lasers, multiple optical switches and detectors connected in sequence.

2. The optoelectronic hybrid integrated delay device of nested structure according to claim 1, characterized in that: The electric delay device comprises a first 1×N radio frequency switch, an N×N radio frequency switch and a second 1×N radio frequency switch which are sequentially cascaded, where N is a natural number not less than 2; The input port of the first 1×N RF switch is the input port of the entire delay device, and the N output ports of the first 1×N RF switch are sequentially connected to the N input ports of the N×N RF switch; The N-1 output ports of the N×N RF switch are sequentially connected to the N-1 input ports of the second 1×N RF switch, the Nth output port of the N×N RF switch is connected to the laser RF input port of the optical delay device, and the Nth input port of the second 1×N RF switch is connected to the detector RF output port of the optical delay device; The output port of the second 1×N radio frequency switch is the output port of the entire delay device.

3. The optoelectronic hybrid integrated delay device of nested structure according to claim 2, characterized in that: The N is 2 m , where m is a natural number.

4. The optoelectronic hybrid integrated delay device of nested structure according to claim 3, characterized in that: N is 4 or 8.

5. The optoelectronic hybrid integrated delay device of nested structure according to any one of claims 1 to 4, characterized in that: The optical delay device includes a laser connected in sequence, a first 1×S optical switch, a group of S×S optical switches cascaded in sequence with the same structure, and a second 1×S optical switch, and a detector connected behind the second 1×S optical switch; wherein S is the number of input / output ports of the 1×S and S×S optical switches, and S is a positive integer not less than 2.

6. The optoelectronic hybrid integrated delay device of nested structure according to claim 5, characterized in that: S is 2 f , where f is a natural number.

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