Multimode quantum interferometer device with certainty

Abstract

The invention relates to a multimode quantum interferometer device with certainty. The technical problems that an existing quantum multi-mode interferometer is small in photon utilization number and low in phase measurement absolute precision are mainly solved. According to the technical scheme, the device comprises a light source, a first linear beam splitter array, an optical parameter amplifier, a sensor, a second linear beam splitter array and a balanced zero beat measuring system. The output end of the light source is connected with the input end of the first linear beam splitter array. The output port of the first linear beam splitter array is connected with the input port of the optical parameter amplifier. The output end of the optical parameter amplifier is connected with the input end of the sensor, the output end of the sensor is connected with the input end of the second linear beam splitter array, and the output end of the second linear beam splitter array is connected with the ith input end of the balanced zero beat measuring system. The 1i-th output end of the first linear beam splitter array is connected with the 1i-th input end of the balanced zero-beat measurement system.

Description

Technical Field

[0001] The present invention belongs to the technical field of quantum precision measurement, and particularly relates to a deterministic multi-mode quantum interferometer device. Background Art

[0002] Precision measurement plays a very important role in deeply understanding nature and exploring potential applications. An interferometer is one of the important tools for precision measurement and can measure many phase-sensitive physical quantities. At present, extremely weak gravitational wave signals have been successfully observed by a laser interferometer. By using quantum technology, an interferometer that breaks through the shot noise limit can be constructed to further improve the sensitivity. However, more parameters need to be precisely measured in practical applications. Therefore, the realization of a multi-mode interferometer that breaks through the shot noise limit, especially one that can measure multiple weak signals submerged in the quantum noise limit, is a very challenging task.

[0003] Combining a multi-mode interferometer with quantum resources can improve the sensitivity and break through the shot noise limit. In 2021, the Korea Advanced Institute of Science and Technology constructed a quantum multi-mode interferometer using a multi-mode NOON state and achieved quantum-enhanced multi-phase estimation, and published "Quantum enhanced multiple-phase estimation with multi-mode N00N states" in Nature Communications 12:5211 (2021). The above research work solved the problem of a multi-mode quantum interferometer breaking through the standard quantum limit. However, the number of photons used in the above method is small and the absolute accuracy of phase measurement is low, which limits the practical application of the interferometer in multi-parameter precision measurement. Summary of the Invention

[0004] The object of the present invention is to solve the technical problems of the existing quantum multi-mode interferometer, such as the small number of photons used and the low absolute accuracy of phase measurement, and to provide a deterministic multi-mode quantum interferometer device. This device can significantly improve the sensitivity by simultaneously compressing noise and amplifying signals, and improve the absolute accuracy of phase measurement.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A deterministic multi-mode quantum interferometer device, which includes a light source (1), a first linear beam splitter array (21), a plurality of optical parametric amplifiers (3i (i = 1, 2,..., M)), a plurality of sensors (4i (i = 1, 2,..., M)), a second linear beam splitter array (22) and a balanced homodyne measurement system (5); the local oscillator light a of the light source (1) L The output end is connected to the first input end of the first linear beam splitter array (21), and the signal light a of the light source (1)S The output end is connected to the second input end of the first linear beam splitter array (21); the pump light a of the light source (1) p The output end is connected to the third input end of the first linear beam splitter array (21); the signal light a output from the 2i (i = 1, 2,..., M) output ports of the first linear beam splitter array (21) S is connected to the first input port of the optical parametric amplifier (3i), and the pump light a output from the 3i (i = 1, 2,..., M) output ports of the first linear beam splitter array (21) p is connected to the second input port of the optical parametric amplifier (3i); the output ends of the plurality of optical parametric amplifiers (3i (i = 1, 2,..., M)) are connected to the input ends of a plurality of sensors (4i (i = 1, 2,..., M)), the output ends of the plurality of sensors (4i (i = 1, 2,..., M)) are respectively connected to a plurality of input ends of the second linear beam splitter array (22), the plurality of output ends of the second linear beam splitter array (22) are respectively connected to the i (i = 1, 2,..., M) input ends of the balanced homodyne measurement system (5), and the 1i (i = 1, 2,..., M) output ends of the first linear beam splitter array (21) are connected to the 1i (i = 1, 2,..., M) input ends of the balanced homodyne measurement system (5).

[0007] Further, the light source (1) includes a tunable laser (1a), a variable beam splitter (1b), a mode cleaner (1c 1 ) and an optical frequency doubler (1c 2 ), the output end of the tunable laser (1a) is connected to the input end of the variable beam splitter (1b), the first output end of the variable beam splitter (1b) is connected to the input end of the mode cleaner (1c 1 ), the second output end of the variable beam splitter (1b) is connected to the input end of the optical frequency doubler (1c 2 ), the first output end of the mode cleaner (1c 1 ) outputs the local oscillator light a L , the second output end of the mode cleaner (1c 1 ) outputs the signal light a S , and the output end of the optical frequency doubler (1c 2 ) outputs the pump light a p .

[0008] Further, the sensor is composed of two high - reflection mirrors and a piezoelectric ceramic. The piezoelectric ceramic is fixed on one of the high - reflection mirrors, and the two high - reflection mirrors are arranged obliquely relative to each other so that the light beam is reflected multiple times between the two high - reflection mirrors to amplify the measurement signal.

[0009] The working principle of the present invention is as follows: The injected laser is equally divided into multiple internal optical fields of the interferometer by the first linear beam splitter array, and then multiple orthogonally phase-compressed optical fields are obtained through the amplification of the optical parametric amplifier. This optical field is directly regarded as the phase-sensitive optical field. Then, each phase-sensitive optical field interacts with the sample multiple times. Finally, the multiple output optical fields carrying signals are coupled by the second linear beam splitter array and measured by a balanced homodyne detector, and the joint measurement and single measurement results of the signal to be measured are obtained through post-processing.

[0010] The beneficial effects of the present invention are as follows:

[0011] 1. The present invention constructs a multimode quantum interferometer using multiple compressed optical fields, and can deterministically achieve multiple phase measurements that break through the shot noise limit.

[0012] 2. The present invention simultaneously uses multiple compressed optical fields as phase-sensitive quantum states, and can simultaneously obtain the joint measurement and single measurement results of multiple samples.

[0013] 3. The present invention incorporates an optical parametric amplifier into the interferometer, which can efficiently utilize the compressed optical field.

[0014] 4. The present invention can achieve multiple high-sensitivity phase measurements. By amplifying the intensity of the phase-sensitive optical field of the interferometer through an optical parametric amplifier, the sensitivity of the interferometer can be improved; and by using the method of multiple interactions between the phase-sensitive optical field and the sample, the signal can be amplified; at the same time, by using the compression of the compressed state to reduce quantum noise, the sensitivity is improved without increasing the power of the phase-sensitive field, solving the practical application of the interferometer in phase measurement.

[0015] 5. The present invention does not require an ultra-high-efficiency quantum light source and a cryogenic detection system, and can operate only with conventional room-temperature systems such as an optical parametric amplifier and a balanced homodyne detector. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the present invention;

[0017] Figure 2 is a schematic structural diagram of the light source part for generating coherent light and pump light of the present invention;

[0018] Figure 3 is a schematic structural diagram of the first linear beam splitter array of the present invention;

[0019] Figure 4 is a schematic parallel structural diagram of the optical parametric amplifier of the present invention;

[0020] Figure 5 is a schematic diagram of the sensor of the present invention;

[0021] Figure 6It is a schematic structural diagram of the balanced homodyne measurement system of the present invention;

[0022] In the figure: 1 - light source, 1a - tunable laser, 1b - variable beam splitter, 1c 1 - mode cleaner, 1c 2 - optical frequency doubler, 21 - first linear beam splitter array, 3 - optical parametric amplifier, 3a - input coupling mirror, 3b - output coupling mirror, 3c, 3d - plano-concave mirror, 3e - first piezoelectric ceramic, 3f - nonlinear crystal, 4 - sensor, 4a, 4b - high reflection mirror, 4c - second piezoelectric ceramic, 5 - balanced homodyne measurement system, 5a - 1:1 optical beam splitter, 5b, 5c - detectors, 5d - power subtractor, 5e - spectrum analyzer. Specific embodiments

[0023] The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0024] As Figure 1 shown, a deterministic multi-mode quantum interferometer device in this embodiment includes a light source 1, a first linear beam splitter array 21, a plurality of optical parametric amplifiers 3i (i = 1, 2,..., M), a plurality of sensors 4i (i = 1, 2,..., M), a second linear beam splitter array 22, and a balanced homodyne measurement system 5; the local oscillator light a L output end of the light source 1 is connected to the first input end of the first linear beam splitter array 21, and the signal light a S output end of the light source 1 is connected to the second input end of the first linear beam splitter array 21; the pump light a p output end of the light source 1 is connected to the third input end of the first linear beam splitter array 21; the signal light a S output from the 2i (i = 1, 2,..., M) output port of the first linear beam splitter array 21 is connected to the first input port of the optical parametric amplifier 3i, and the pump light a p output from the 3i (i = 1, 2,..., M) output port of the first linear beam splitter array 21 is connected to the second input port of the optical parametric amplifier 3i; the output ends of the plurality of optical parametric amplifiers 3i (i = 1, 2,..., M) are connected to the input ends of the plurality of sensors 4i (i = 1, 2,..., M), the output ends of the plurality of sensors 4i (i = 1, 2,..., M) are respectively connected to the plurality of input ends of the second linear beam splitter array 22, the plurality of output ends of the second linear beam splitter array 22 are respectively connected to the i (i = 1, 2,..., M) input ends of the balanced homodyne measurement system 5, and the 1i (i = 1, 2,..., M) output ends of the first linear beam splitter array 21 are connected to the 1i (i = 1, 2,..., M) input ends of the balanced homodyne measurement system 5.

[0025] AsFigure 2 As shown, the light source 1 includes a tunable laser 1a, a variable beam splitter 1b, and a mode cleaner 1c 1 and an optical frequency doubler 1c 2 , the output end of the tunable laser 1a is connected to the input end of the variable beam splitter 1b, the first output end of the variable beam splitter 1b is connected to the input end of the mode cleaner 1c 1 , the second output end of the variable beam splitter 1b is connected to the input end of the optical frequency doubler 1c 2 , the first output end of the mode cleaner 1c 1 outputs the local oscillator light a L , the second output end of the mode cleaner 1c 1 outputs the signal light a S , the output end of the optical frequency doubler 1c 2 outputs the pump light a p . The 895nm light field output by the tunable laser 1a is input to the variable beam splitter 1b. The output end of the variable beam splitter 1b is divided into two parts. One part is input to the mode cleaner 1 c1 . After improving the beam quality, the local oscillator light a L and the signal light a S are output. The other part is input to the optical frequency doubler 1c 2 . The pump light a 2 is output by the optical frequency doubler 1c p .

[0026] As Figure 3 shown, the first linear beam splitter array 21 includes three beam splitter arrays 21a, 21b, and 21c. The local oscillator light a 1 output by the mode cleaner 1c L is equally divided into three local oscillator lights a L1 , a L2 and a L3 with the same power through the beam splitter array 21a; the signal light a 1 output by the mode cleaner 1c S is equally divided into three seed lights a S1 , a S2 and a S3 with the same power through the beam splitter array 21b; the pump light ap output by the optical frequency doubler 1c 2 is equally divided into three pump lights a p1 , a p2 and a p3 with the same power through the beam splitter array 21c.

[0027] As Figure 4As shown in the figure, the optical parametric amplifier 3 is composed of an input coupling mirror 3a, an output coupling mirror 3b, two plano-concave mirrors 3c and 3d, a first piezoelectric ceramic 3e, and a nonlinear crystal 3f. The input coupling mirror 3a, the output coupling mirror 3b, and the two plano-concave mirrors 3c and 3d form a resonant cavity of a "butterfly-shaped" ring cavity, and this resonant cavity has the performance of low thermal effect. Among them, for the input coupling mirror 3a, a high-reflection film is coated on the probe light field; for the output coupling mirror 3b, a film with a transmittance of 5% for the probe field is coated. The plano-concave mirrors 3c and 3d are coated with an anti-reflection film for the pump field and a high-reflection film for the probe field. The nonlinear crystal 3f is placed between the two plano-concave mirrors 3c and 3d. A first piezoelectric ceramic 3e with a large elongation is arranged on one of the plano-concave mirrors 3d to actively scan the cavity length or lock the cavity length to resonate with the injected probe light field.

[0028] As Figure 5 shown, the sensor 4 is composed of two high-reflection mirrors 4a and 4b and a second piezoelectric ceramic 4c. The second piezoelectric ceramic 4c is fixed on one of the high-reflection mirrors 4a. The two high-reflection mirrors are arranged obliquely relative to each other, so that the light beam is reflected multiple times between the two high-reflection mirrors to amplify the measurement signal.

[0029] As Figure 6 shown, the balanced homodyne measurement system 5 includes a 50 / 50 optical beam splitter 5a, a pair of high-signal-to-noise detectors 5b and 5c, a power subtractor 5d, and a spectrum analyzer 5e. The detector 5b is arranged on the refracted light path of the optical beam splitter 5a, and the detector 5c is arranged on the transmitted light path of the optical beam splitter 5a. The output ends of the detectors 5b and 5c are connected to the input end of the power subtractor 5d, and the output end of the power subtractor 5d is connected to the spectrum analyzer 5e. The local oscillator light a 1 output by the mode cleaner 1c L and the signal light field a out generated by the second linear beam splitter array 22 are respectively divided into two parts with exactly equal power through the optical beam splitter 5a, and then interfere. The interfered light field is injected onto the diodes of the two detectors 5b and 5c. Then, the currents output from the output ends of the detectors 5b and 5c are input to the power subtractor 5d. The two currents are subtracted by the power subtractor 5d and then transmitted to the spectrum analyzer 5e. The spectrum analyzer 5e measures and analyzes the quadrature component quantum noise of the output signal to obtain the information of the sample to be measured.

Claims

1. A deterministic multi-mode quantum interferometer device, characterized in that: The invention comprises a light source (1), a first linear beam splitter array (21), a plurality of optical parametric amplifiers (3i (i=1, 2, ...M)), a plurality of sensors (4i (i=1, 2, ...M)), a second linear beam splitter array (22) and a balanced zero-beat measurement system (5); the local oscillator light a of the light source (1) L The output end is connected to the first input end of the first linear beam splitter array (21), and the signal light a of the light source (1) S The output end is connected to the second input end of the first linear beam splitter array (21); the pump light a of the light source (1) p The output end is connected to the third input end of the first linear beam splitter array (21); the signal light a outputted from the 2ith (i=1, 2, ...M) output port of the first linear beam splitter array (21) S The first linear beam splitter array (21) is connected to the first input port of the optical parametric amplifier (3i), and the pump light a outputted from the 3ith (i=1, 2, ...M) output port of the first linear beam splitter array (21) is p connected to the second input port of the optical parametric amplifier (3i); the output ends of the plurality of optical parametric amplifiers (3i (i=1, 2, ...M)) are connected to the input ends of the plurality of sensors (4i (i=1, 2, ...M)), the output ends of the plurality of sensors (4i (i=1, 2, ...M)) are respectively connected to the plurality of input ends of the second linear beam splitter array (22), the plurality of output ends of the second linear beam splitter array (22) are respectively connected to the i-th (i=1, 2, ...M) input end of the balanced zero-beat measurement system (5), and the 1i-th (i=1, 2, ...M) output end of the first linear beam splitter array (21) is connected to the 1i-th (i=1, 2, ...M) input end of the balanced zero-beat measurement system (5).

2. A deterministic multi-mode quantum interferometer device according to claim 1, characterized in that: The sensor is composed of two high-reflection mirrors and a piezoelectric ceramic. The piezoelectric ceramic is fixed on a high-reflection mirror. The two high-reflection mirrors are relatively tilted so that the light beam is reflected multiple times between the two high-reflection mirrors to amplify the measurement signal.

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