阅读说明：本技术 不等臂干涉仪两臂插损标定装置及系统 (Two-arm insertion loss calibration device and system for unequal-arm interferometer ) 是由 陈柳平 王林松 王其兵 万相奎 于 2021-08-09 设计创作，主要内容包括：本发明公开的不等臂干涉仪两臂插损标定装置,涉及通信设备测试领域,包括光源、光纤移相器、第一分束器、第二分束器、第三分束器、功率计和计算器,其中,第一分束器和第二分束器组成等臂干涉仪,第二分束器和第三分束器组成待测不等臂干涉仪,光源用于制备脉冲光,第一分束器用于将脉冲光分束为第一脉冲光和第二脉冲光,光纤移相器用于调节第一脉冲光与第二脉冲光之间的相位差,以使经过等臂干涉仪干涉后的脉冲光全部进入待测不等臂干涉的长臂或短臂,功率计用于分别计算待测不等臂干涉的长臂及短臂输出的脉冲光的功率,得到第一脉冲光功率和第二脉冲光功率,提高了精确度及效率。(The invention discloses a two-arm insertion loss calibration device of an unequal-arm interferometer, which relates to the field of communication equipment testing and comprises a light source, an optical fiber phase shifter, a first beam splitter, a second beam splitter, a third beam splitter, a power meter and a calculator, wherein the first beam splitter and the second beam splitter form the equal-arm interferometer, the second beam splitter and the third beam splitter form the unequal-arm interferometer to be tested, the light source is used for preparing pulsed light, the first beam splitter is used for splitting the pulsed light into first pulsed light and second pulsed light, the optical fiber phase shifter is used for adjusting the phase difference between the first pulsed light and the second pulsed light so as to enable the pulsed light interfered by the equal-arm interferometer to be tested to completely enter a long arm or a short arm interfered by the unequal-arm to be tested, the power meter is used for respectively calculating the power of the pulsed light output by the long arm and the short arm interfered by the unequal-arm to be tested to obtain the power of the first pulsed light and the power of the second pulsed light, the accuracy and efficiency are improved.)

1. The utility model provides a two arms of arm interferometer that differ are inserted and are decreased calibration device which characterized in that includes: a light source, a fiber phase shifter, a first beam splitter BS1, a second beam splitter BS2, a third beam splitter BS3, a power meter and a calculator, wherein:

the first beam splitter BS1 and the second beam splitter BS2 constitute an equal arm interferometer;

the second beam splitter BS2 and the third beam splitter BS3 form an unequal arm interferometer to be measured;

the light source is used for preparing pulsed light;

a first beam splitter BS1 for splitting the pulsed light into first and second pulsed lights;

the optical fiber phase shifter is used for adjusting the phase difference between the first pulse light and the second pulse light so that all the pulse light interfered by the equal-arm interferometer enters the long arm or the short arm interfered by the unequal arm to be measured;

the power meter is used for respectively calculating the power of pulsed light output by the long arm and the short arm interfered by the unequal arm to be detected to obtain first pulsed light power and second pulsed light power;

the calculator is used for respectively obtaining the insertion loss of the long arm and the insertion loss of the short arm of the unequal arm interference to be detected according to the first pulse light power and the second pulse light power;

and the calculator is also used for obtaining the difference between the long arm insertion loss and the short arm insertion loss of the unequal arm interference to be detected according to the long arm insertion loss and the short arm insertion loss of the unequal arm interference to be detected.

2. The unequal-arm interferometer two-arm insertion loss calibration device according to claim 1, wherein:

the optical fiber phase shifter is further used for adjusting the phase difference between the first pulse light and the second pulse light to pi, so that the pulse light subjected to interference of the equal-arm interferometer only enters the long arm subjected to interference of the unequal arm to be detected.

3. The unequal-arm interferometer two-arm insertion loss calibration device according to claim 1, wherein:

the optical fiber phase shifter is further used for adjusting the phase difference between the first pulse light and the second pulse light to be 0, so that the pulse light subjected to interference of the equal-arm interferometer only enters the short arm subjected to interference of the unequal arm to be measured.

4. The unequal-arm interferometer two-arm insertion loss calibration device according to claim 3, further comprising:

and the optical fiber delay line is used for adjusting the lengths of the two walls of the equal-arm interferometer so that the lengths of the two walls of the equal-arm interferometer are kept consistent.

5. The unequal-arm interferometer two-arm insertion loss calibration device according to claim 4, further comprising:

and the optical attenuator is used for adjusting the power of the first/second pulse light so that the power of the first pulse light and the power of the second pulse light are kept consistent.

6. The two-arm insertion loss calibration device for the interferometer according to claim 2, further comprising:

and the first single-photon detector SPD1 is used for detecting the photon number of the pulse light output by the long arm of the unequal arm interferometer to be detected in real time.

7. The unequal-arm interferometer two-arm insertion loss calibration device according to claim 3, further comprising:

and the second single-photon detector SPD2 is used for detecting the photon number of the pulse light output by the short arm of the unequal arm interferometer to be detected in real time.

8. The unequal-arm interferometer two-arm insertion loss calibration device according to claim 7, wherein:

and the calculator is also used for calculating the contrast of the to-be-measured unequal arm interferometer according to the photon number of the pulsed light output by the long arm of the to-be-measured unequal arm interferometer and the photon number of the pulsed light output by the short arm of the to-be-measured unequal arm interferometer.

9. An unequal-arm interferometer two-arm insertion loss calibration system, which is characterized by comprising the unequal-arm interferometer two-arm insertion loss calibration device as claimed in any one of claims 1 to 8.

Technical Field

The invention relates to the field of quantum communication equipment testing, in particular to a calibration device and a calibration system for insertion loss of two arms of an unequal arm interferometer.

Background

Unequal-arm fiber optic interferometers are very important devices in quantum communication systems and other related fields, and the performance of the unequal-arm fiber optic interferometers often determines the performance of the quantum communication systems. The performance parameters of the unequal-arm optical fiber interferometer mainly comprise insertion loss of two arms of the unequal-arm optical fiber interferometer and insertion loss difference of the two arms, and the quality of an interference result is determined. The insertion loss of the two arms and the insertion loss difference of the two arms are generally required to be controlled within 0.5 dB.

Aiming at the insertion loss of two arms of an unequal arm optical fiber interferometer and the insertion loss difference of the two arms, most enterprises do not calibrate at present, or an oscilloscope or a single-photon detector is adopted to simply observe the amplitude difference of front pulses and rear pulses output by the two arms of the unequal arm optical fiber interferometer, and then the insertion loss of the two arms of the unequal arm optical fiber interferometer and the insertion loss difference of the two arms are calculated according to the amplitude difference, and the scheme has the following defects:

the subjective factors are large, so that the accuracy of the obtained result is low, the specific insertion loss cannot be intuitively read, the result is obtained by reverse extrapolation, and the efficiency is low.

Disclosure of Invention

The embodiment of the invention provides a calibration device and a calibration system for insertion loss of two arms of an unequal-arm interferometer, which are used for solving the defects of low accuracy and low efficiency in the prior art.

In order to achieve the above object, in a first aspect, an apparatus for calibrating a two-arm insertion loss of an unequal-arm interferometer provided by an embodiment of the present invention includes a light source, a fiber phase shifter, a first beam splitter BS1, a second beam splitter BS2, a third beam splitter BS3, a power meter, and a calculator, where:

the first beam splitter BS1 and the second beam splitter BS2 constitute an equal arm interferometer.

The second beam splitter BS2 and the third beam splitter BS3 form an unequal arm interferometer to be measured.

The light source is used for preparing pulsed light.

A first beam splitter BS1 for splitting the pulsed light into a first pulsed light and a second pulsed light.

And the optical fiber phase shifter is used for adjusting the phase difference between the first pulse light and the second pulse light so as to enable all the pulse light subjected to interference of the equal-arm interferometer to enter the long arm or the short arm subjected to interference of the unequal arm to be detected.

And the power meter is used for respectively calculating the power of the pulse light output by the long arm and the short arm interfered by the unequal arm to be detected to obtain the power of the first pulse light and the power of the second pulse light.

And the calculator is used for respectively obtaining the insertion loss of the long arm and the insertion loss of the short arm of the unequal arm interference to be detected according to the first pulse light power and the second pulse light power.

And the calculator is also used for obtaining the difference between the long arm insertion loss and the short arm insertion loss of the unequal arm interference to be detected according to the long arm insertion loss and the short arm insertion loss of the unequal arm interference to be detected.

In a preferred embodiment of the present invention, the optical fiber phase shifter is further configured to adjust a phase difference between the first pulse light and the second pulse light to pi, so that the pulse light interfered by the equal-arm interferometer enters only the long arm where the unequal-arm measurement is interfered.

In a preferred embodiment of the present invention, the optical fiber phase shifter is further configured to adjust a phase difference between the first pulse light and the second pulse light to 0, so that the pulse light interfered by the equal-arm interferometer enters only a short arm of the unequal-arm measurement interferometer.

As a preferred embodiment of the present invention, the device for calibrating the insertion loss of the two arms of the equal-arm interferometer further comprises an optical fiber delay line, which is used for adjusting the lengths of the two walls of the equal-arm interferometer, so that the lengths of the two walls of the equal-arm interferometer are kept consistent.

As a preferred embodiment of the present invention, the apparatus for calibrating insertion loss of two arms of an unequal-arm interferometer further comprises:

and the optical attenuator is used for adjusting the power of the first/second pulse light so that the power of the first pulse light and the power of the second pulse light are kept consistent.

As a preferred embodiment of the present invention, the apparatus for calibrating insertion loss of two arms of an unequal-arm interferometer further comprises:

and the first single-photon detector SPD1 is used for detecting the photon number of the pulse light output by the long arm of the unequal arm interferometer to be detected in real time.

As a preferred embodiment of the present invention, the apparatus for calibrating insertion loss of two arms of an unequal-arm interferometer further comprises:

and the second single-photon detector SPD2 is used for detecting the photon number of the pulse light output by the short arm of the unequal arm interferometer to be detected in real time.

As a preferred embodiment of the present invention, the calculator is further configured to calculate the contrast of the inequality arm interferometer to be measured according to the number of photons of the pulsed light output by the long arm of the inequality arm interferometer to be measured and the number of photons of the pulsed light output by the short arm of the inequality arm interferometer to be measured.

In a second aspect, an embodiment of the present invention provides a calibration system for the insertion loss of two arms of an unequal arm interferometer, where the calibration system for the insertion loss of two arms of an unequal arm interferometer includes the calibration apparatus for the insertion loss of two arms of an unequal arm interferometer according to the first aspect.

The device and the system for calibrating the insertion loss of the two arms of the unequal-arm interferometer provided by the embodiment of the invention have the following beneficial effects:

the accuracy and efficiency are improved by the combination of the light source, the fiber phase shifter, the first beam splitter BS1, the second beam splitter BS2, the third beam splitter BS3, the power meter and the calculator.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a calibration apparatus for insertion loss of two arms of an unequal-arm interferometer according to an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a two-arm insertion loss calibration apparatus of another interferometer with unequal arms according to an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a two-arm insertion loss calibration system of another interferometer with unequal arms according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Example 1

As shown in fig. 1, the apparatus for calibrating insertion loss of two arms of an unequal-arm interferometer provided by the embodiment of the present invention includes a light source, a fiber phase shifter, a first beam splitter BS1, a second beam splitter BS2, a third beam splitter BS3, a power meter, and a calculator, wherein:

the first beam splitter BS1 and the second beam splitter BS2 constitute an equal arm interferometer.

The arm interferometers may be MZ interferometers or michelson interferometers including a beam splitter.

The second beam splitter BS2 and the third beam splitter BS3 form an unequal arm interferometer to be measured.

The unequal-arm interferometer may be an MZ interferometer or a michelson interferometer including a beam splitter.

The light source is used for preparing pulsed light.

The first beam splitter BS1 is used to split the pulsed light into first and second pulsed light.

The optical fiber phase shifter is used for adjusting the phase difference between the first pulse light and the second pulse light, so that the pulse light subjected to interference of the equal-arm interferometer completely enters the long arm or the short arm subjected to interference of the unequal arm to be measured.

As a specific embodiment of the present invention, in an ideal state, when the optical fiber phase shifter adjusts the phase difference between the first pulse light and the second pulse light to be pi, all the pulse light after interference of the equal-arm interferometer enters the long arm of the to-be-measured unequal-arm interference.

Specifically, in an ideal state, when the optical fiber phase shifter adjusts the phase difference between the first pulse light and the second pulse light to be 0, all the pulse light subjected to interference of the equal-arm interferometer enters the short arm to be measured for unequal-arm interference.

The power meter is used for respectively calculating the pulse light power output by the long arm and the short arm of the unequal arm interference to be measured to obtain the first pulse light power and the second pulse light power.

And the calculator is used for respectively obtaining the insertion loss of the long arm and the insertion loss of the short arm of the unequal arm interference to be detected according to the first pulse light power and the second pulse light power.

And the calculator is also used for obtaining the difference between the long arm insertion loss and the short arm insertion loss of the unequal arm interference to be detected according to the long arm insertion loss and the short arm insertion loss of the unequal arm interference to be detected.

Specifically, first beamsplitter BS1, second beamsplitter BS2, and third beamsplitter BS3 are each 50:50 beamsplitters.

The device for calibrating the insertion loss of the two arms of the unequal arm interferometer comprises a light source, an optical fiber phase shifter, a first beam splitter BS1, a second beam splitter BS2, a third beam splitter BS3, a power meter and a calculator, wherein the first beam splitter BS1 and the second beam splitter BS2 form the equal arm interferometer, the second beam splitter BS2 and the third beam splitter BS3 form the unequal arm interferometer to be measured, the light source is used for preparing pulsed light, the first beam splitter BS1 is used for splitting the pulsed light into first pulsed light and second pulsed light, the optical fiber phase shifter is used for adjusting the phase difference between the first pulsed light and the second pulsed light so that the pulsed light interfered by the equal arm interferometer completely enters the long arm or the short arm interfered by the unequal arm to be measured, the power meter is used for respectively calculating the power of the pulsed light output by the long arm and the short arm interfered by the unequal arm to be measured to obtain the first pulsed light power and the second pulsed light power, the calculator is used for respectively obtaining the insertion loss of the long arm and the insertion loss of the short arm interfered by the unequal arm to be detected according to the first pulse light power and the second pulse light power, obtaining the insertion loss difference between the long arm and the short arm interfered by the unequal arm to be detected according to the insertion loss of the long arm and the insertion loss of the short arm interfered by the unequal arm to be detected, and improving the accuracy and the efficiency.

Example 2

As shown in fig. 2, the two-arm insertion loss calibration apparatus for an unequal-arm interferometer provided by the embodiment of the present invention includes, in addition to the light source, the optical fiber phase shifter, the first beam splitter BS1, the second beam splitter BS2, the third beam splitter BS3, the power meter, and the calculator shown in fig. 1, an optical attenuator, an optical fiber delay line, a first single-photon detector SPD1, a second single-photon detector SPD2, a fourth beam splitter BS4, and a fifth beam splitter BS5, where:

the optical fiber delay line is used for adjusting the lengths of the two walls of the equal-arm interferometer, so that the lengths of the two walls of the equal-arm interferometer are kept consistent.

The optical attenuator is used for adjusting the power of the first pulse light and the second pulse light, so that the power of the first pulse light and the power of the second pulse light are kept consistent.

The fourth beam splitter BS4 is used to split the pulsed light output by the long arm or the short arm of the unequal arm interferometer to be measured into two beams, one beam is input to the fifth beam splitter BS5, and the other beam is input to the power meter.

Specifically, the calculator is a single chip microcomputer.

Fig. 1 is a schematic structural diagram of a two-arm insertion loss calibration device of an unequal-arm interferometer under an ideal condition that partial pulse light leaks and is input into a short arm and a long arm of the unequal-arm interferometer to be measured when phase difference between first pulse light and second pulse light is not considered and is adjusted to be pi/0. Fig. 2 is a schematic structural diagram of the calibration apparatus for the insertion loss of the two arms of the unequal-arm interferometer under the ideal condition that pulsed light leaks and is input into the short/long arms of the unequal-arm interferometer to be measured when the phase difference between the first pulsed light and the second pulsed light is adjusted to pi/0, wherein:

the first single-photon detector SPD1 is used for detecting the photon number of pulse light output by the long arm of the inequality arm interferometer to be detected in real time.

The second single-photon detector SPD2 is used for detecting the photon number of the pulse light output by the short arm of the inequality arm interferometer to be detected in real time.

The calculator calculates the contrast of the to-be-detected unequal arm interferometer according to the number of photons of the pulsed light output by the long arm and the short arm of the to-be-detected unequal arm interferometer, wherein the contrast is the ratio of the number of photons of the pulsed light output by the long arm and the short arm of the to-be-detected unequal arm interferometer, and the value of the contrast is made to be maximum or minimum by adjusting the phase shifter, so that the pulsed light is completely input into the long arm or the short arm of the to-be-detected unequal arm interferometer. The larger the contrast is, the higher the accuracy of the calculated insertion loss of the long arm or the short arm of the to-be-measured unequal arm interferometer is, and the calculation shows that if the contrast is 100:1, the calculated insertion loss error of the long arm or the short arm of the to-be-measured unequal arm interferometer is 0.04 dB.

Specifically, fourth beam splitter BS4 is a 1:999 beam splitter and fifth beam splitter BS5 is a 50:50 beam splitter.

Example 3

As shown in fig. 3, the two-arm insertion loss calibration system of the unequal-arm interferometer according to the embodiment of the present invention includes the two-arm insertion loss calibration apparatus of the unequal-arm interferometer shown in fig. 1 or fig. 2.

It will be appreciated that the relevant features of the method and apparatus described above are referred to one another. In addition, "first", "second", and the like in the above embodiments are for distinguishing the embodiments, and do not represent merits of the embodiments.

The above are merely examples of the present application and are not intended to limit the present application. Various modifications and changes may occur to those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

It should be noted that the above-mentioned embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalent alternatives or equivalent variations fall within the protection scope of the present invention.