Device and method for generating quantum compression laser

Abstract

The invention provides a device and method for generating quantum compression laser, and belongs to the technical field of non-classical light fields. The problem that an existing compressed light source cannot have compressibility and coherence at the same time is solved. In order to solve the technical problem, the technical scheme adopted by the invention is as follows: the laser device comprises a low-noise coherent laser system, a pump light source preparation system, a high-compression-degree compressed state light field preparation system and a high-precision auxiliary locking loop system, and seed light emitted by the low-noise coherent laser system is injected into the pump light source preparation system to generate pump light; pump light is injected into a high-compression-degree compressed state light field preparation system to generate compressed light, the compressed light is injected into a compressed laser preparation system to generate compressed laser after being subjected to phase locking through a high-precision auxiliary locking loop system, and the compressed laser is detected by a compressed laser detection and evaluation system after being subjected to phase locking through the high-precision auxiliary locking loop system; the method is applied to a non-classical light field.

Description

Technical Field

[0001] The present invention provides a device and a method for generating quantum squeezed laser, belonging to the technical field of non-classical optical fields. Background Art

[0002] Compared with the squeezed state optical field, the squeezed laser takes into account both the coherence of classical laser and the quantum noise squeezing characteristics. The excellent coherence of the laser is the product of the strong interaction of stimulated emission light amplification. During the stimulated excitation of the active particles, the quantum characteristics are destroyed; the preparation of the squeezed state optical field depends on the spontaneous emission process, and the quantum correlation characteristics are maintained through the phase-sensitive manipulation of weak interactions, which deteriorates the coherence of the output optical field. Therefore, the existing laser excitation and squeezed state preparation schemes cannot achieve the unity of the coherence and quantum nature of the optical field, which brings great challenges to the experimental preparation of the squeezed laser. Although a theoretical scheme for preparing the squeezed laser by using the squeezed vacuum state to enhance the stimulated emission light amplification of the atomic gain medium has been proposed at present, providing a theoretical basis for the realization of the squeezed laser, this scheme requires controlling the pump light detuning amount and only retaining the light-atom interaction, which is difficult to experiment, and the pump light detuning leads to a reduction in squeezing. Summary of the Invention

[0003] In order to solve the technical problem that the existing squeezed light sources cannot simultaneously have compressibility and coherence, the present invention proposes a device and a method for generating quantum squeezed laser with high compression degree, high power and narrow linewidth. The purpose is to make the optical parametric oscillation cavity work in the stimulated emission state by means of compression injection to generate the squeezed laser, and to realize the stable output of the quantum squeezed laser through the improvement of the optical path and the control system.

[0004] In order to solve the above technical problem, the technical solution adopted by the present invention is: a device for generating quantum squeezed laser, comprising a low-noise coherent laser system, a pump light source preparation system, a high-compression squeezed state optical field preparation system and a high-precision auxiliary locking loop system; The low-noise coherent laser system outputs a first coherent light, a second coherent light and a seed light; After the first coherent light is injected into the pump light source preparation system, pump light is generated. The pump light includes a first pump light and a second pump light. The first pump light and the seed light are injected into the squeezed state optical field preparation system to generate squeezed light; The second coherent light is injected into the high-precision auxiliary locking loop system to generate frequency-shifted coherent light. The frequency-shifted coherent light is phase-locked with the squeezed light and then injected into the squeezed laser preparation system; The squeezed light interacts with the second pump light to generate squeezed laser, and the squeezed laser is injected into the squeezed laser detection and evaluation system.

[0005] Further, the high-precision auxiliary locking loop system includes a first scanning locking loop, a second scanning locking loop, and a third scanning locking loop; the first scanning locking loop includes a first detector, the first detector is electrically connected to a first mixer, and the first mixer is also electrically connected to a first signal driving source and a high-compression degree squeezed light field preparation system; the first signal driving source is also electrically connected to an electro-optic modulator, the electro-optic modulator is optically connected to a first phase shifter and a high-compression degree squeezed light field preparation system, and the first phase shifter is also optically connected to a low-noise coherent laser system; The second scanning locking loop includes a second detector, the input end of the second detector is optically connected to the output ends of the phase shifter and the high-compression degree squeezed light field preparation system through a 99:1 beam splitter 1; the output end of the second detector is electrically connected to a second mixer, the second mixer is electrically connected to a second signal driving source and the phase shifter, and the phase shifter is also optically connected to a low-noise coherent laser system; The third scanning locking loop includes a third detector, the third detector is electrically connected to a third mixer, the third mixer is also electrically connected to a third signal driving source and a second phase shifter, and the second phase shifter is also optically connected to the output end of the pump source preparation system; the third detector is optically connected to the compression laser preparation system and the compression laser detection and evaluation system through a 1:99 beam splitter.

[0006] Further, the compression laser detection and evaluation system includes a linewidth measurement unit and a compression characteristic measurement unit; The linewidth measurement unit includes an analysis cavity, the analysis cavity is optically connected to a 1:99 beam splitter and a folding mirror mount 1, the folding mirror mount 1 is optically connected to a fourth detector, the fourth detector is electrically connected to a fourth mixer, and the fourth mixer is also electrically connected to a fourth signal driving source and an oscilloscope; The compression characteristic measurement unit includes a half-wave plate, the half-wave plate is optically connected to a polarization beam splitter PBS and a folding mirror mount 2; the polarization beam splitter PBS is electrically connected to a self-balanced detector SHD, and the self-balanced detector SHD is also electrically connected to a spectrum analyzer; the folding mirror mount 2 is also connected to an optical power meter; the folding mirror mount 2 is optically connected to the folding mirror mount 1.

[0007] Further, the high-compression degree squeezed light field preparation system includes an OPO1 optical parametric oscillator, the input end of the OPO1 optical parametric oscillator is optically connected to the pump source preparation system and the low-noise coherent laser system through a dichroic mirror 1; the output end of the OPO1 optical parametric oscillator is optically connected to a 99:1 beam splitter 1, and the 99:1 beam splitter 1 is also optically connected to the compression laser preparation system.

[0008] Further, the compressed laser preparation system includes an OPO2 optical parametric oscillator, and the OPO2 optical parametric oscillator is optically connected to a pump light source preparation system, a high-compression degree squeezed state optical field preparation system, and a compressed laser detection and evaluation system through an OI2 optical isolator optical path.

[0009] Further, the pump light source preparation system includes a second harmonic generator, and the second harmonic generator is optically connected to a low-noise coherent laser system through a 20:80 beam splitter and a 50:50 beam splitter 1 in sequence, and the second harmonic generator is optically connected to a high-compression degree squeezed state optical field preparation system and a compressed laser preparation system through a 50:50 beam splitter 2.

[0010] Further, the low-noise coherent laser system includes a laser, and the laser is optically connected to the 50:50 beam splitter 1.

[0011] Further, the first pump light and the seed light are injected into the squeezed state optical field preparation system to generate quadrature amplitude squeezed light or phase squeezed light; The quadrature amplitude squeezed light interacts with the second pump light to generate quadrature phase compressed laser, and the quadrature phase squeezed light interacts with the second pump light to generate quadrature amplitude compressed laser.

[0012] A method for generating quantum compressed laser, and the method for generating quantum compressed laser uses a device for generating quantum compressed laser according to any one of the above.

[0013] The beneficial effects of the present invention compared with the prior art are as follows: The low-noise coherent laser system of the device for generating quantum compressed laser of the present invention generates pump light, locks the squeezed light generated by the high-compression degree squeezed state optical field preparation system through a high-precision auxiliary locking loop system, locks the relative phase between the squeezed light and the frequency-shifted coherent light to zero phase through a high-precision auxiliary locking loop system, and the squeezed light is injected into the compressed laser preparation system by means of compressed injection to generate compressed laser. Compared with the squeezed state optical field, the compressed laser takes into account both the coherence of classical laser and the quantum noise squeezing characteristics, and has potential application value in the field of quantum optics and even broader fields of physics. By locking the relative phase between the squeezed light and the pump light through a high-precision auxiliary locking loop system, the stable output of single-longitudinal-mode compressed laser is realized. Description of the Drawings

[0014] The following further describes the present invention with reference to the drawings: Figure 1 is a schematic diagram of the principle of the present invention; Figure 2 is a schematic diagram of the compressed laser generation principle of the present invention; Figure 3Schematic diagram of the high-precision auxiliary locking loop system of the present invention; Figure 4 Operation flowchart of the high-precision auxiliary locking loop system of the present invention; In the figure: 1 is a low-noise coherent laser system, 2 is a pump light source preparation system, 3 is a high-precision auxiliary locking loop system, 4 is a high-compression squeezed light field preparation system, 5 is a squeezed laser preparation system, 6 is a squeezed laser detection and evaluation system, 7 is a laser, 8 is a 50:50 beam splitter I, 9 is a 20:80 beam splitter, 10 is a second harmonic generator, 11 is a 50:50 beam splitter II, 12 is a first phase shifter, 13 is a second phase shifter, 14 is an electro-optic modulator, 15 is a first detector, 16 is an OI1 optical isolator, 17 is a dichroic mirror I, 18 is an OPO1 optical parametric oscillator, 19 is an acousto-optic frequency shifter I, 20 is an acousto-optic frequency shifter II, 21 is a third phase shifter, 22 is a dichroic mirror II, 23 is a second detector, 24 is a 99:1 beam splitter I, 25 is an OI2 optical isolator, 26 is an OPO2 optical parametric oscillator, 27 is a 1:99 beam splitter, 28 is a third detector, 29 is a folding mirror mount I, 30 is a folding mirror mount II, 31 is a half-wave plate, 32 is a polarization beam splitter PBS, 33 is an analysis cavity, 34 is a fourth detector, 35 is a self-balancing detector SHD, 36 is an oscilloscope, 37 is an optical power detector, 38 is a spectrum analyzer, 60 is a first scanning locking loop, 61 is a second scanning locking loop, 62 is a third scanning locking loop. Specific embodiments

[0015] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate relative orientation or position relationships, and are 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 operated in a specific orientation, and thus should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0016] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0017] As Figures 1 to 4 shown, the present invention provides a device for generating quantum squeezed laser, including a low-noise coherent laser system 1, a pump light source preparation system 2, a high-compression squeezed state optical field preparation system 4, and a high-precision auxiliary locking loop system 3.

[0018] The low-noise coherent laser system 1 outputs a first coherent light, a second coherent light, and a seed light. The first coherent light generates pump light after being injected into the pump light source preparation system 2. The pump light includes a first pump light and a second pump light. The first pump light and the seed light are injected into the high-compression squeezed state optical field preparation system 4 to generate a high-compression squeezed state optical field (hereinafter replaced by "squeezed light"). The second coherent light generates a frequency-shifted coherent light through acousto-optic frequency shifting operation. The frequency-shifted coherent light and the squeezed light are phase-locked and then injected into the compressed laser preparation system 5. The second pump light is injected into the compressed laser preparation system 5 and interacts with the phase-locked squeezed light to generate compressed laser. The compressed laser is injected into the compressed laser detection and evaluation system 6 to measure the linewidth, power, and compression degree of the compressed laser.

[0019] Specifically, the laser output by the low-noise coherent laser system 1 has the characteristics of strong coherence and low noise. The low-noise coherent laser system 1 includes a low-noise laser 7. In this embodiment, the low-noise laser is a 1064nm laser. After the laser emitted by the low-noise coherent laser system 1 is injected into the 50:50 beam splitter 8, it is injected into the high-precision auxiliary locking loop system 3 through the reflection end of the 50:50 beam splitter 8, providing the second coherent light for the high-precision auxiliary locking loop system 3. The second coherent light passes through the acousto-optic frequency shifter 19 and the acousto-optic frequency shifter 20 in sequence to generate frequency-shifted coherent light, and the generated frequency-shifted coherent light is injected into the third phase shifter 21. The laser emitted by the low-noise coherent laser system 1 is injected into the 20:80 beam splitter 9 through the transmission end of the 50:50 beam splitter 8 and outputs the first coherent light and the seed light. The first coherent light is injected into the second harmonic generator 10 in the pump light source preparation system 2 to generate pump light. The pump light outputs two beams of pump light after passing through the 50:50 beam splitter 11. The first pump light is emitted from the reflection end of the 50:50 beam splitter 11, and the second pump light is emitted from the transmission end of the 50:50 beam splitter 11. The first pump light and the seed light are injected into the OPO1 optical parametric oscillator 18 in the squeezed light field preparation system 4 to generate quadrature amplitude squeezed light or phase squeezed light, and the relative phase of the quadrature amplitude squeezed light or phase squeezed light and the frequency-shifted coherent light is locked by the high-precision auxiliary locking loop system 3.

[0020] The squeezed light and the frequency-shifted coherent light after locking the phase are injected into the cavity of the OPO2 optical parametric oscillator 26. By injecting a highly squeezed squeezed light field, the nonlinear interaction can be effectively enhanced, the coupling strength of the optical parametric down-conversion process can be increased, and stimulated emission dominates, enabling the cavity of the OPO2 optical parametric oscillator 26 to operate above the threshold, so that the squeezed light interacts with the second pump light to generate squeezed laser. More specifically, the first pump light is injected into the frequency-degenerate OPO1 optical parametric oscillator 18 after passing through the dichroic mirror 17, and the seed light is injected into the OPO1 optical parametric oscillator 18 after passing through the first phase shifter 12, the electro-optic modulator 14, the OI1 optical isolator 16, and the dichroic mirror 17 in sequence. The locked squeezed light and the second pump light are injected into the frequency-degenerate OPO2 optical parametric oscillator 26 of the squeezed laser preparation system 5 after passing through the dichroic mirror 22 and the OI2 optical isolator 25 in sequence, and the relative phase of the squeezed light and the second pump light is locked by the high-precision auxiliary locking loop system 3 to generate squeezed laser. The quadrature amplitude squeezed light interacts with the second pump light to generate quadrature phase squeezed laser, and the quadrature phase squeezed light interacts with the second pump light to generate quadrature amplitude squeezed laser.

[0021] The compression laser detection and evaluation system 6 is used to detect the indexes of single longitudinal mode compression laser, that is, to measure the linewidth, power and compression degree of the compression laser, and includes a linewidth measurement unit and a compression characteristic measurement unit. The linewidth measurement unit is used to evaluate and measure the linewidth of the compression laser. The linewidth measurement unit includes an analysis cavity 33, the optical path of the analysis cavity 33 is connected to a 1:99 beam splitter 27 and a first folding mirror holder 29, the optical path of the first folding mirror holder 29 is connected with a fourth detector 34, the fourth detector 34 is electrically connected to a fourth mixer, the fourth mixer is also electrically connected to a fourth signal driver and an oscilloscope 36, and is used to measure the linewidth of the compression laser. The compression characteristic measurement unit includes a half-wave plate 31, the optical path of the half-wave plate 31 is connected to a polarization beam splitter PBS32 and a second folding mirror holder 30, the polarization beam splitter PBS32 is electrically connected to a self-balancing detector SHD35, and the self-balancing detector SHD35 is also electrically connected to a spectrum analyzer 38, and is used to measure the compression degree of the compression laser; the second folding mirror holder 30 is also electrically connected to an optical power detector 37, and the optical power detector is used to measure the power of the compression laser, and the second folding mirror holder 30 is optically connected to the first folding mirror holder 29.

[0022] Specifically, the compression laser is injected into the analysis cavity 33 after passing through the OI2 optical isolator 25. At the same time, the first folding mirror holder 29 and the second folding mirror holder 30 are placed in the optical path at 45°. The cavity length of the analysis cavity 33 is scanned and the scanning result is uploaded to the oscilloscope 36. The PDH error signal in the cavity length locking loop of the analysis cavity 33 can be read on the oscilloscope 36. The PDH error signal is divided into two parts. One part is fed back to the piezoelectric ceramic PZT attached to the cavity mirror of the analysis cavity 33 to lock the cavity length of the analysis cavity 33, and the other part is used to extract the frequency noise PSD, and the linewidth of the compression laser is calculated by using the β-separation line theory. Fold up the first folding mirror holder 29 and put down the second folding mirror holder 30, and the compression laser can be introduced into the optical power detector 37, so as to measure the optical power of the compression laser. Fold up the first folding mirror holder 29 and the second folding mirror holder 30, the compression laser is polarized by the half-wave plate 31 and then split by the polarization beam splitter PBS32. The powers of the two beams of light after splitting are equal. Then the two beams of light are jointly injected into the self-balancing detector SHD35 for addition / subtraction operation. The output end of the self-balancing detector SHD35 is connected to a spectrum analyzer 38. After the spectrum analyzer 38 analyzes the signal in the self-balancing detector SHD35, the quadrature amplitude noise of the compression laser can be measured, and the compression degree of the compression laser can be obtained.

[0023] There is a cavity length difference between the cavities of the frequency-degenerate OPO1 (optical parametric oscillator) 18 and OPO2 (optical parametric oscillator) 26. The cavity mode of OPO2 only resonates with one squeezed mode of OPO1, that is, the quantum state of the optical field of a certain squeezed mode of OPO1 in a certain direction with reduced uncertainty matches the frequency of the cavity mode of OPO2, and energy exchange or interaction can be effectively carried out. In other words, the frequency of the squeezed mode of OPO1 exactly meets the resonance condition of the cavity mode of OPO2, enabling a resonance phenomenon to occur between the two, ensuring the stable generation and output of single longitudinal mode squeezed laser.

[0024] The high-precision auxiliary locking loop system 3 includes a first scanning locking loop 60, a second scanning locking loop 61, and a third scanning locking loop 62.

[0025] The first scanning locking loop 60 is used to lock the cavity length of the OPO1 and the relative phase between the first pump light and the seed light in the OPO1. Specifically, the first scanning locking loop 60 includes a first detector 15. The first detector 15 is electrically connected to a first mixer. The first mixer is also electrically connected to a first signal driving source and the OPO1; the first signal driving source is also electrically connected to an electro-optic modulator 14. The electro-optic modulator 14 is optically connected to a first phase shifter 12 and an OI1 optical isolator 16. The first phase shifter 12 is also optically connected to a low-noise coherent laser system 1 through a 20:80 beam splitter 9. The OI1 optical isolator 16 is also optically connected to a pump light source preparation system 2 and a high-compression squeezed state optical field preparation system 4 through a first dichroic mirror 17. More specifically, the seed light sequentially passes through the reflection end of the 20:80 beam splitter 9, the first phase shifter 12, and the electro-optic modulator 14. After applying a phase modulation of 56.3 MHz in the electro-optic modulator 14, it is injected into the OPO1 through the OI1 optical isolator 16. The first detector 15 detects the pre-cavity reflection signal of the OPO1 through the OI1 photoelectric isolator 16, and then demodulates it through the first mixer to obtain an error signal, which is used to lock the cavity length of the OPO1 and the relative phase between the first pump light and the seed light to a preset value. More specifically, when the preset value of the relative phase between the first pump light and the seed light is 0, the OPO1 outputs squeezed light with quadrature phase squeezing; if the preset value of the relative phase between the first pump light and the seed light is π, the OPO1 outputs squeezed light with quadrature amplitude squeezing.

[0026] The second scanning locking circuit 61 is used to lock the relative phase of the squeezed light and the frequency-shifted coherent light to zero. Specifically, the second scanning locking circuit 61 includes a second detector 23. The optical path of the second detector 23 is connected to a 99:1 beam splitter 24. The 99:1 beam splitter 24 is also optically connected to the output end of the OPO1 optical parametric oscillator 18, a third phase shifter 21, and a dichroic mirror 22. The third phase shifter 21 is optically connected to the acousto-optic frequency shifter 20, the acousto-optic frequency shifter 19, and the reflective end of the 50:50 beam splitter 8 in sequence, and then optically connected to the low-noise coherent laser system 1. The second detector 23 is electrically connected to a mixer 2, and the mixer 2 is also electrically connected to the second signal driving source and the third phase shifter 21, thus forming a phase-locking loop. The squeezed light emitted from the OPO1 optical parametric oscillator 18 generates a beat frequency with the frequency-shifted coherent light at the 99:1 beam splitter 24. A second detector 23 is installed at the transmission end of the 99:1 beam splitter 24 for detecting and demodulating the above beat frequency signal. The second detector 23 is electrically connected to a mixer 2, the mixer 2 is electrically connected to the third phase shifter 21, and the mixer 2 is also electrically connected to a second signal driving source, thus forming a feedback loop to lock the relative phase of the squeezed light and the frequency-shifted coherent light to the zero phase.

[0027] The third scanning locking circuit 62 is used to lock the cavity length of the OPO2 optical parametric oscillator 26, lock the relative phase between the injected squeezed light and the second pump light to a preset value, and then generate squeezed laser. Specifically, the third scanning locking circuit 62 includes a third detector 28. The third detector 28 is electrically connected to a mixer 3, and the mixer 3 is also electrically connected to a third signal driving source and a second phase shifter 13; the third detector 28 is optically connected to the reflective end of a 1:99 beam splitter 27, the incident end of the 1:99 beam splitter 27 is optically connected to an OI2 optical isolator 25, and the transmission end of the 1:99 beam splitter 27 is optically connected to the analysis cavity 33 of the squeezed laser detection and evaluation system 6. More specifically, 1% of the 20 MHz frequency-shifted coherent light and 99% of the quadrature-phase squeezed light are injected into the OPO2 optical parametric oscillator 26. The third scanning locking circuit 62 locks the relative phase between the squeezed light and the second pump light to π. After the second pump light and the quadrature-phase squeezed light interact in the cavity of the OPO2 optical parametric oscillator 26, squeezed laser with quadrature amplitude squeezing is generated; if 1% of the 20 MHz frequency-shifted coherent light and 99% of the quadrature amplitude squeezed light are injected into the OPO2 optical parametric oscillator 26, then the third scanning locking circuit 62 locks the relative phase between the squeezed light and the second pump light to 0. After the second pump light and the quadrature amplitude squeezed light interact in the cavity of the OPO2 optical parametric oscillator 26, squeezed laser with quadrature phase squeezing is generated.

[0028] The relative phase of the squeezed light and the second pump light is locked by the third scanning locking circuit 62. Specifically, the frequency-shifted coherent light injected into the optical parametric oscillator 26 of OPO2 passes through the optical isolator 25 of OI2 and then is injected into the 1:99 beam splitter II 27. A third detector 28 is installed at the reflection end of the 1:99 beam splitter II 27. After mixing the 40 MHz signal with the signal detected by the third detector 28, an error signal is generated. The generated error signal is fed back to the second phase shifter 13 to control the phase of the second pump light, and the relative phase between the frequency-shifted coherent light and the second pump light is locked. Since the phase relationship between the frequency-shifted coherent light and the injected squeezed light is 0, the relative phase between the squeezed light and the second pump light can be locked by the coherent control method.

[0029] The compression injection method is that after injecting the squeezed light generated by the optical parametric oscillator 18 of OPO1 into the optical parametric oscillator 26 of OPO2, the parametric gain of the optical parametric oscillator 26 of OPO2 is exponentially amplified. In the optical parametric oscillator 26 of OPO2, when the pump light power is lower than the preset oscillation threshold, the rate of photon generation by the optical parametric oscillator 26 of OPO2 is greater than the attenuation rate of the optical resonator in the optical parametric oscillator 26 of OPO2, showing the phenomenon of stimulated emission generated by the optical parametric oscillator 26 of OPO2 when the pump light power exceeds the preset oscillation threshold, and compressed laser is output.

[0030] The method for generating quantum compressed laser adopts the above device for generating quantum compressed laser.

[0031] In order to generate compressed laser, the device for generating quantum compressed laser according to the present invention uses two low-loss optical parametric oscillators and a highly compressed squeezed state optical field preparation system 4, optimizes the cavity escape efficiency of the optical parametric oscillator, the transmission loss in the optical path, and the interference efficiency between the light beams, so that the total efficiencies of the two optical parametric oscillators reach 97% and 94% respectively, reducing the influence of optical loss on the compression degree; the influence of phase jitter on the compression degree is suppressed by the high-precision auxiliary locking circuit system 3, so that the two optical parametric oscillators generate squeezed light and compressed laser respectively.

[0032] The device for generating quantum squeezed laser of the present invention stably generates squeezed laser through a high-precision auxiliary locking loop system 3. During the preparation of the squeezed laser, first, the cavity length and relative phase of the OPO1 optical parametric oscillator 18 are locked by adjusting the high voltage to generate highly squeezed light, and then it enters the coherent locking module. The squeezed light and the frequency-shifted coherent light are subjected to beat frequency, and the relative phase between the frequency-shifted coherent light and the squeezed light is locked by adjusting the high-precision auxiliary locking loop system 3. The locked squeezed light is injected into the OPO2 optical parametric oscillator 26. After locking the cavity length of the OPO2 optical parametric oscillator 26 by adjusting the high voltage, the relative phase between the squeezed light and the second pump light is locked by the high-precision auxiliary locking loop system 3, and the squeezed light and the pump light interact to generate squeezed laser. The generated squeezed laser enters the squeezed laser detection system, and the line width, power and squeezing degree of the squeezed laser can be measured.

[0033] The working principle of the present invention is as follows: The low-noise coherent laser system 1 of the present invention outputs the first coherent light, the second coherent light and the seed light. The first coherent light is injected into the pump light source preparation system 2 to generate the first pump light and the second pump light. The first pump light and the seed light are injected into the high-squeezing-degree squeezed light field preparation system 4 to generate squeezed light, and the cavity length of the OPO1 optical parametric oscillator 18 and the relative phase of the squeezed light are locked to preset values through the first scanning locking loop 60; after the second coherent light passes through the third phase shifter 21 to output frequency-shifted coherent light, it undergoes beat frequency with the squeezed light at the 99:1 beam splitter 24, and the relative phase between the squeezed light and the frequency-shifted coherent light is locked to zero through the second scanning locking loop 61; the second pump light and the locked squeezed light are injected into the squeezed laser preparation system 5 through the OI2 optical isolator 25. After the OPO2 optical parametric oscillator 26 transmits the injected squeezed light, it is injected into the 1:99 beam splitter 27 through the OI2 optical isolator 25, and the relative phase between the squeezed light and the second pump light is locked to a preset value through the third scanning locking loop 62 to generate squeezed laser. The squeezed laser enters the squeezed laser detection and evaluation system 6, and the line width, power and squeezing degree of the squeezed laser can be measured.

[0034] Regarding the specific structure of the present invention, it should be noted that the connection relationships between the various component modules adopted by the present invention are definite and achievable. Except for the special descriptions in the embodiments, the specific connection relationships can bring corresponding technical effects and, on the premise of not relying on the execution of corresponding software programs, solve the technical problems proposed by the present invention. The models of the components, modules, and specific components, the connection methods between them, and the conventional usage methods and predictable technical effects brought by the above technical features, except for the specific descriptions, all belong to the publicly disclosed content in patents, journal papers, technical manuals, technical dictionaries, and textbooks that those skilled in the art can obtain before the filing date, or belong to the prior art such as conventional techniques and common general knowledge in the art, and need not be elaborated. This enables the technical solution provided in this case to be clear, complete, and achievable, and can reproduce or obtain the corresponding physical product according to this technical means.

[0035] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A device for generating quantum compressed laser, characterized in that: It comprises a low-noise coherent laser system (1), a pump light source preparation system (2), a high-compression compressed state light field preparation system (4) and a high-precision auxiliary locking loop system (3); The low-noise coherent laser system (1) outputs a first coherent light, a second coherent light and a seed light; The first coherent light is injected into the pump light source preparation system (2) to generate pump light, the pump light includes a first pump light and a second pump light, and the first pump light and the seed light are injected into the compressed state light field preparation system (4) to generate compressed light; The second coherent light is injected into the high-precision auxiliary locking loop system (3) to generate frequency-shifted coherent light, and the frequency-shifted coherent light is injected into the compressed laser preparation system (5) after being phase-locked with the compressed light; The compressed light interacts with the second pump light to generate compressed laser light, and the compressed laser light is injected into the compressed laser detection and evaluation system (6).

2. The device for generating quantum compressed laser according to claim 1, characterized in that: The high-precision auxiliary locking circuit system (3) comprises a first scanning locking circuit (60), a second scanning locking circuit (61) and a third scanning locking circuit (62); The first scanning locking loop (60) comprises a first detector (15), the first detector (15) being electrically connected to a mixer 1, the mixer 1 being also electrically connected to a first signal driving source and a high-compression degree squeezed-state light field preparation system (4); the first signal driving source being also electrically connected to an electro-optic modulator (14), the electro-optic modulator (14) being optically connected to a first phase shifter (12) and the high-compression degree squeezed-state light field preparation system (4), the first phase shifter (12) being also optically connected to a low-noise coherent laser system (1); The second scanning locking loop (61) comprises a second detector (23), the input end of the second detector (23) being optically connected to the third phase shifter (21) and the output end of the high-compression compressed state light field preparation system (4) via a 99:1 beam splitter 1 (24); the output end of the second detector (23) is electrically connected to a mixer 2, the mixer 2 is electrically connected to a second signal driving source and the third phase shifter (21), and the third phase shifter (21) is also optically connected to a low-noise coherent laser system (1); The third scanning locking loop (62) includes a third detector (28), the third detector (28) is electrically connected to a third mixer, the third mixer is also electrically connected to a third signal driving source and a second phase shifter (13), the second phase shifter (13) is also optically connected to the output end of the pump light source preparation system (2); the third detector (28) is optically connected to the output end of the compressed laser preparation system (5) and the compressed laser detection and evaluation system (6) via a 1:99 beam splitter (27).

3. The device for generating quantum compressed laser according to claim 2, characterized in that: The compression laser detection and evaluation system (6) comprises a line width measurement unit and a compression characteristic measurement unit; The line width measurement unit comprises an analysis cavity (33), the analysis cavity (33) is optically connected to a 1:99 beam splitter (27) and a folding mirror frame (29), the folding mirror frame (29) is optically connected to a fourth detector (34), the fourth detector (34) is electrically connected to a mixer (4), and the mixer (4) is also electrically connected to a fourth signal driving source and an oscilloscope (36); The compression characteristic measuring unit comprises a half wave plate (31), wherein the half wave plate (31) is optically connected to a polarization beam splitter PBS (32) and a folding mirror frame 2 (30); the polarization beam splitter PBS (32) is electrically connected to a self-balancing detector SHD (35), and the self-balancing detector SHD (35) is also electrically connected to a spectrum analyzer (38); the folding mirror frame 2 (30) is also connected to an optical power detector 37; and the folding mirror frame 2 (30) is optically connected to the folding mirror frame 1 (29).

4. The device for generating quantum compressed laser according to claim 2, characterized in that: The high-compression squeezed-state light field preparation system (4) comprises an OPO1 optical parametric oscillator (18), the input end of the OPO1 optical parametric oscillator (18) is optically connected to a pump light source preparation system (2) and a low-noise coherent laser system (1) via a dichroic mirror (17); the output end of the OPO1 optical parametric oscillator (18) is optically connected to a 99:1 beam splitter (24), and the 99:1 beam splitter (24) is also optically connected to a squeezed laser preparation system (5).

5. The device for generating quantum compressed laser according to claim 1, characterized in that: The compressed laser preparation system (5) comprises an OPO2 optical parametric oscillator (26), and the OPO2 optical parametric oscillator (26) is optically connected to a pump light source preparation system (2), a high-compression compressed state light field preparation system (4), and a compressed laser detection and evaluation system (6) via an OI2 optical isolator (25).

6. The device for generating quantum compressed laser according to claim 1, characterized in that: The pump light source preparation system (2) comprises a second harmonic generator (10), the second harmonic generator (10) being connected to a low-noise coherent laser system (1) via a 20:80 beam splitter (9) and a 50:50 beam splitter 1 (8) optical path in sequence, and the second harmonic generator (10) being connected to a high-compression compressed state light field preparation system (4) and a compressed laser preparation system (5) via a 50:50 beam splitter 2 (11) optical path.

7. The device for generating quantum compressed laser according to claim 6, characterized in that: The low-noise coherent laser system (1) comprises a laser (7), wherein the laser (7) is optically connected to a 50:50 beam splitter (8).

8. The device for generating quantum compressed laser according to claim 1, characterized in that: The first pump light and seed light are injected into the compressed state light field preparation system (4) to generate orthogonal amplitude compressed light or phase compressed light; The orthogonal amplitude compression light generates orthogonal phase compression laser light after interaction with the second pump light, and the orthogonal phase compression light generates orthogonal amplitude compression laser light after interaction with the second pump light.

9. A method for generating quantum compression laser, characterized in that: The method for generating quantum compressed laser uses a device for generating quantum compressed laser as described in any one of claims 1 to 8.

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