HIGH-SPEED REAL-TIME SAMPLING AND MEASURING DEVICE AND METHOD FOR MID-INFRARED ULTRAFAST LIGHT SIGNAL

Abstract

A device for high-speed real-time sampling of mid-infrared ultrafast light signals includes a time domain amplification unit and a detection unit. The time domain amplification unit is used to perform sampling and time domain amplification on signal light incident to the time domain amplification unit, and convert the signal light of a mid-infrared band into a near-infrared/visible band. The detection unit is used to receive and record information of the to-be-detected signal light processed by the time domain amplification unit to realize high-speed real-time sampling and measurement of the mid-infrared ultrafast light signal. The present disclosure can accurately obtain subpicosecond transient characteristics of the light signal, breaks through the capacity limit to the response rate of a traditional photoelectric detector, the bandwidth of the oscilloscope and the like, and is applicable to femtosecond-level mid-infrared ultrafast light signals.

Claims

1. A high-speed real-time sampling and measuring device for a mid-infrared ultrafast light signal, comprising a time domain amplification unit (20) and a detection unit (30), wherein the time domain amplification unit (20) is configured to perform sampling and time domain amplification on received to-be-detected signal light (1), and convert signal light of a mid-infrared band into a near-infrared/visible band; the detection unit (30) is configured to receive and record information of the to-be-detected signal light (1) processed by the time domain amplification unit (20).

2. The high-speed real-time sampling and measuring device for the mid-infrared ultrafast light signal according to claim 1, wherein the time domain amplification unit (20) comprises a beam combiner (9), a signal light path and a pump light path which are respectively located in two incident light paths of the beam combiner (9), and a new frequency light path located in an emergent light path of the beam combiner (9); the signal light path comprises an attenuator (2), a first polarization controller (3) and a first dispersive medium (4) which are arranged along the light path; the pump light path comprises a pump source (5), a second polarization controller (7) and a second dispersive medium (8) which are arranged along the light path; the new frequency light path comprises a lithium niobate waveguide (10), a filter (11) and a third dispersive medium (12) which are arranged in sequence along the light path; in the signal light path, the attenuator (2) is configured to adjust the intensity of the signal light such that the signal light conforms to an intensity condition for generating three-wave mixing; the first polarization controller (3) is configured to adjust the polarization of the signal light such that the signal light conforms to a phase matching condition for generating the three-wave mixing; the first dispersive medium (4) is configured to perform secondary phase modulation on a frequency domain of the signal light; in the pump light path, the pump source (5) is configured to provide pump light in the three-wave mixing process; the second polarization controller (7) is configured to adjust the polarization of the pump light such that the pump light conforms to the phase matching condition for generating the three-wave mixing; and the second dispersive medium (8) is configured to perform the secondary phase modulation on a frequency domain of the pump light; the beam combiner (9) is configured to combine the signal light output by the signal light path and the pump light output by the pump light path; the lithium niobate waveguide (10) is configured to receive combined light output by the beam combiner (9) and generate a three-wave mixing effect; the filter (11) is configured to filter out the pump light and the signal light output from the lithium niobate waveguide (10) to obtain new frequency light generated by the three-wave mixing; and the third dispersive medium (12) is configured to perform the secondary phase modulation on a frequency domain of the new frequency light.

3. The high-speed real-time sampling and measuring device for the mid-infrared ultrafast light signal according to claim 2, wherein the time domain amplification unit (20) further comprises a time delay line (6) located in the pump light path or the signal light path and configured to adjust the pump light and the signal light to be synchronized on the time domain.

4. The high-speed real-time sampling and measuring device for the mid-infrared ultrafast light signal according to claim 3, wherein the detection unit (30) comprises a real-time oscilloscope (14) and a photoelectric detector (13); the input end of the photoelectric detector (13) is connected with the output end of the time domain amplification unit (20); and the output end of the photoelectric detector (13) is connected with the real-time oscilloscope (14).

5. The high-speed real-time sampling and measuring device for the mid-infrared ultrafast light signal according to claim 4, wherein the photoelectric detector (13) is a photoelectric detector (13) of the GHz bandwidth, and the real-time oscilloscope (14) is a real-time oscilloscope (14) of the GHz bandwidth.

6. The high-speed real-time sampling and measuring device for the mid-infrared ultrafast light signal according to claim 5, wherein the first dispersive medium (4), the second dispersive medium (8) and the third dispersive medium (12) are all single mode fibers, and have different dispersion sizes.

7. A high-speed real-time sampling and measuring method for a mid-infrared ultrafast light signal based on the high-speed real-time sampling and measuring device for the mid-infrared ultrafast light signal according to claim 1, comprising the following steps: Step I, performing, by a time domain amplification unit, sampling and time domain amplification on signal light of a mid-infrared band incident to the time domain amplification unit, and converting the signal light of the mid-infrared band into a near-infrared/visible band; Step II, receiving and recording, by a detection unit, information of to-be-detected signal light processed by the time domain amplification unit to realize high-speed real-time sampling and measurement of the mid-infrared ultrafast light signal.

8. The high-speed real-time sampling and measuring method for the mid-infrared ultrafast light signal according to claim 7, wherein Step I specifically comprises: controlling a pump source to emit pump light; adjusting, by an attenuator, the intensity of the signal light such that the signal light conforms to an intensity condition for generating three-wave mixing; adjusting, by a first polarization controller and a second polarization controller, polarization directions of the signal light and the pump light such that the signal light and the pump light conform to a phase matching condition for generating the three-wave mixing; adjusting, by a time delay line, a relative time delay between the pump light and the signal light to enable the pump light and the signal light to be synchronized on the time domain; performing, by a first dispersive medium and a second dispersive medium, secondary phase modulation on frequency domains of the signal light and the pump light respectively to introduce linear frequency chirp to the pump light and broaden the time domain of the signal light; combining, by a beam combiner, the signal light and the pump light subjected to the secondary phase modulation, and then injecting the combined light into a lithium niobate waveguide to generate an efficient three-wave mixing effect; filtering, by a filter, the combined light to output new frequency signal light generated by the three-wave mixing, and performing, by a third dispersive medium, the secondary phase modulation on a frequency domain of the new frequency light and thus realizing time domain amplification of the signal light.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 is a schematic diagram of the present disclosure;

[0030] FIG. 2 is a structural schematic diagram of a device in an embodiment of the present disclosure;

[0031] FIG. 3a is an input signal diagram of the present disclosure; and

[0032] FIG. 3b is a diagram of sampling and time domain amplification results of FIG. 3a.

[0033] Numerals in the drawings: 1: to-be-detected signal light; 2: attenuator; 3: first polarization controller; 4: first dispersive medium; 5: pump source; 6: time delay line; 7: second polarization controller; 8: second dispersive medium; 9: beam combiner; 10: lithium niobate waveguide; 11: filter; 12: third dispersive medium; 13: detector; 14: real-time oscilloscope; 20: time domain amplification unit; and 30: detection unit.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The present disclosure is further described below in conjunction with the drawings and specific embodiments.

[0035] The present disclosure constructs a time domain amplification unit based on an efficient low-threshold three-wave mixing effect in a lithium niobate waveguide to realize high-multiplying-power low-distortion time domain amplification of a mid-infrared ultrafast light signal, and records information of to-be-detected signal light by using a detection unit, thereby realizing high-speed real-time sampling and measurement of the mid-infrared ultrafast light signal.

[0036] Referring to FIG. 1 and FIG. 2, the present embodiment provides a high-speed real-time sampling and measuring device for a mid-infrared ultrafast light signal based on time domain amplification, including a time domain amplification unit 20 configured to perform sampling and time domain amplification on to-be-detected signal light 1, and a detection unit 30 configured to detect data processed by the time domain amplification unit 20.

[0037] The time domain amplification unit 20 includes an attenuator 2 configured to adjust the intensity of the signal light, a first dispersive medium 4 configured to perform secondary phase modulation on a frequency domain of the signal light, a pump source 5 configured to provide pump light for a three-wave mixing process, a second dispersive medium 8 configured to perform the secondary phase modulation on a frequency domain of the pump light, a first polarization controller 3 and a second polarization controller 7 which are respectively configured to perform polarization adjustment on the signal light and the pump light, a time delay line 6 configured to adjust a relative time delay between the signal light and the pump light, a beam combiner 9 configured to combine the modulated signal light and pump light, a high-nonlinearity lithium niobate waveguide 10 configured to generate a three-wave mixing effect, a filter 11 configured to filter out the pump light, the signal light and the like to obtain new frequency light generated by the three-wave mixing, and a third dispersive medium 12 configured to perform the secondary phase modulation on a frequency domain of the new frequency light.

[0038] In the present embodiment, the attenuator 2, the first polarization controller 3 and the first dispersive medium 4 are arranged in sequence along a light path and located in one incident light path of the beam combiner 9. The pump source 5, the time delay line 6, the second polarization controller 7 and the second dispersive medium 8 are arranged in sequence along a light path and located in another incident light path of the beam combiner 9. The high-nonlinearity lithium niobate waveguide 10, the filter 11 and the third dispersive medium 12 are arranged in sequence along a light path and located in an emergent light path of the beam combiner 9. The to-be-detected signal light 1 entering the time domain amplification unit 20 passes through the attenuator 2, the first polarization controller 3 and the first dispersive medium 4 in sequence to enter the beam combiner 9. The pump light passes through the time delay line 6, the second polarization controller 7 and the second dispersive medium 8 in sequence, and then enters the beam combiner 9. The beam combiner 9 combines the signal light and the pump light emitted from the two incident light paths, and the combined light is output to the detection unit 30 after passing through the high-nonlinearity lithium niobate waveguide 10, the filter 11 and the third dispersive medium 12 in sequence.

[0039] The detection unit 30 includes a photoelectric detector 13 for receiving data and a real-time oscilloscope 14. The input end of the photoelectric detector 13 is connected with the output end of the time domain amplification unit 20 to acquire information of the to-be-detected signal light 1. The output end of the photoelectric detector 13 is connected with the input end of the real-time oscilloscope 14. The photoelectric detector 13 is a photoelectric detector 13 of the GHz bandwidth. The real-time oscilloscope 14 is a real-time oscilloscope 14 of the GHz bandwidth.

[0040] A high-speed real-time sampling and measuring method for a mid-infrared ultrafast light signal based on time domain amplification is implemented by the following process, including the following steps that:

[0041] 1) a pump source 5 emits pump light; an attenuator 2 is used to adjust the intensity of signal light entering a time domain amplification unit 20 to enable the signal light to conform to an intensity condition for generating three-wave mixing; a time delay line 6 is used to adjust a relative time delay between the pump light and the signal light in the time domain amplification unit 20 to ensure that the pump light and the signal light are synchronized on the time domain; a second polarization controller 7 and a first polarization controller 3 are respectively used to adjust polarization directions of the pump light and the signal light in the time domain amplification unit 20 such that the pump light and the signal light conform to a phase matching condition for generating the three-wave mixing; a second dispersive medium 8 and a first dispersive medium 4 are respectively used to perform secondary phase modulation on frequency domains of the pump light and the signal light; a beam combiner 9 combines the pump light and the signal light, and then the combined light is injected into a high-nonlinearity lithium niobate waveguide 10 to generate an efficient three-wave mixing effect; a new frequency light generated by the three-wave mixing is obtained after the combined light passes through a filter 11, and a third dispersive medium 12 is used to perform the secondary phase modulation on a frequency domain of the new frequency light and thus realizing high-multiplying-power low-distortion time domain amplification of the signal light;

[0042] 2) a detection unit 30 is used to record information of the signal light output by the time domain amplification unit 20 in real time to realize high-speed real-time sampling and measurement of the mid-infrared ultrafast light signal.

[0043] The present disclosure injects the to-be-detected signal light 1 into the high-speed real-time sampling and measuring device for the mid-infrared ultrafast light signal based on the time domain amplification, and uses the detection unit 30 to record the information of the to-be-detected signal light 1, thus realizing the high-speed real-time sampling and measurement of the mid-infrared ultrafast light signal.

[0044] The working principle of the present disclosure is as follows:

[0045] In the time domain amplification unit, the two polarization controllers are used to adjust the polarization directions of the pump light and the signal light respectively such that the pump light and the signal light conform to the phase matching condition for generating the three-wave mixing. The time delay line is used to adjust the relative time delay between the pump light and the signal light to ensure that the pump light and the signal light are synchronized on the time domain. The attenuator is used to adjust the intensity of the signal light such that the signal light conforms to the intensity condition for generating the three-wave mixing. The dispersive mediums are respectively used to perform the secondary phase modulation (namely linear chirp introduced to the pump light as well as time domain broadening of the signal light, and input dispersion serving for a time domain amplification system) on the frequency domains of the pump light and the signal light. The beam combiner combines the pump light and the signal light, and then the combined light is injected into the lithium niobate waveguide to generate the efficient three-wave mixing effect (conforming to energy conservation and momentum conservation conditions). The new frequency light generated by the three-wave mixing is obtained after the combined light passes through the filter, and the dispersive medium is used to perform the secondary phase modulation (output dispersion serving for a time domain amplification system) on the frequency domain of the new frequency light and thus realizing the high-multiplying-power low-distortion time domain amplification of the signal light. The detection unit is used to record the information of the signal light output by the time domain amplification unit in real time to realize high-speed real-time sampling and measurement of the mid-infrared ultrafast light signal.

[0046] Referring to FIG. 3a and FIG. 3b, sampling and time domain amplification results are illustrated. The high-multiplying-power low-distortion time domain amplification of the mid-infrared ultrafast light signal can be realized by the time domain amplification technology. Therefore, low-distortion time domain amplification more than 600 times can be realized by the time domain amplification method, and thus the high-speed real-time sampling and measurement of the mid-infrared ultrafast light signal are realized by the oscilloscope and the photoelectric detector of the GHz bandwidth.