CN213092083U - High-efficiency forecasting single-photon system - Google Patents
High-efficiency forecasting single-photon system Download PDFInfo
- Publication number
- CN213092083U CN213092083U CN202021909979.1U CN202021909979U CN213092083U CN 213092083 U CN213092083 U CN 213092083U CN 202021909979 U CN202021909979 U CN 202021909979U CN 213092083 U CN213092083 U CN 213092083U
- Authority
- CN
- China
- Prior art keywords
- idler
- light
- photon
- high efficiency
- forecasting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
Abstract
The patent of the utility model relates to an introduce quantum blocked high efficiency forecast single photon system at the idler light path, characterized by is in forecast single photon system, and after signal light and idler sent, increase a high-quality optics microcavity at the idler light path, add N type atomic gas in the chamber, utilize quantum regulation and control atomic gas to produce and realize the jam to the many photon state of idler light to the strong kerr optics nonlinearity of idler photon to improve the efficiency of idler detector forecast single photon.
Description
Technical Field
The utility model belongs to the technical field of the light quantum information, in particular to system of single photon is forecasted to high efficiency.
Background
With the development of optical quantum information technology (including quantum communication, quantum sensing, quantum simulation, linear quantum computation and the like), people have more and more interest in a real single photon source. Many different implementations have been investigated, such as using single molecule or atomic excitation, diamond color centers, quantum dots, and pulsed or continuous wave parametric down-conversion sources, among others. A single photon source based on conversion under spontaneous parameters is always a single photon generation method with the best performance and the most extensive application in the photon information technology due to the advantages of being indistinguishable, high in purity, simple in preparation process and the like (see Nature Nanotechnology 12, 1026 (2017)). However, the method for preparing the single photon source has a fatal defect, the probability of generating the multi-photon pair is gradually increased while the pump laser power is increased, and the result causes that the predicted single photon is easy to be subjected to false alarm. When the idler detector is responsive, there is a probability that it is a multiphoton signal, such that the signal pattern is actually a multiphoton state. This false alarm rate increases with increasing pump laser power. How to accurately judge whether the idler frequency detector detects the single photon signal is an important index for forecasting the quality of the single photon source, which has important significance for improving the performance of the single photon source and even can greatly promote the development of the photon information technology.
Disclosure of Invention
The purpose of the invention is as follows: the utility model discloses there is the problem of wrong report to current forecast single photon technique, the utility model provides a system of single photon is forecasted to high efficiency, the in-process of conversion photon to production under high pumping laser arouses the parameter, utilize quantum blocking effect to solve the problem that has the mistake to report in the forecast single photon system, can greatly improve the forecast efficiency of idler detector single photon in normal atmospheric temperature environment, thereby improve forecast signal single photon production efficiency, and keep high purity, furthermore, through switching photon production system and photon blocking system under the separation parameter, greatly the simplified system realizes the degree of difficulty, like figure 1.
In order to achieve the above purpose, the utility model adopts the following technical scheme:
four reflecting plano-concave mirrors 1-1, 1-2, 1-3, 1-4 are utilized to form two sets of high-quality optical cavities.
A II-type quasi-phase-matched PPKTP nonlinear crystal 2 with a domain period reversal structure is placed in a first optical cavity, and a pump laser pump PPKTP crystal with adjustable waveform, time length and power is used for inducing a spontaneous parameter down-conversion process to generate a pair of parameter light, namely an idler light and a signal light.
The pump laser is incident through a mirror 1-1 coated with an antireflection film, passes through two ends 2-1 and 2-2 of a PPKTP crystal coated with the antireflection film, and then is emitted through a mirror 1-2 coated with the antireflection film.
The idler light and the signal light exit through the mirror 1-2 having a low reflectivity.
The pump laser is separated from the signal light and the idler frequency light by a dichroic mirror 3.
The idler light is orthogonal to the signal light polarization. The signal light is reflected and guided out through the polarization beam splitter 4, while the idler frequency light enters the second optical cavity through the mirrors 1-3 coated with antireflection films and then interacts with atoms through the atom bubbles 5 to form a stable cavity mode.
The idler light is stabilized in the second optical cavity and exits through a mirror 1-4 having a relatively low reflectivity.
The idler light is detected by a single photon detector 8 after passing through a filter 7. The filter means 7 is used to filter out the control light entering the idler channel.
The control light applied to the atoms enters the atomic bubble 5 after passing through a reflector 6-1 to induce a strong optical Kerr nonlinearity for the idler frequency light, and then is guided out through a reflector 6-2.
Strong kerr nonlinearity for the idler light is generated by controlling light to regulate N-level type atomic gas (see figure 2), so that the idler light multi-photon state | Ni>（ni>1) Blocking is performed so that only single photon states can pass. The idler photons are measured by a single photon detector 8, and if the photons are detected, the signal light path obtains high-quality single photons.
The utility model has the advantages of under normal atmospheric temperature, through adding N type atomic bubble induced idler light quantum blocking effect in the forecast single photon system idler light path and block the multiphoton transmission of idler light to improve the accuracy of idler light single photon forecast. In the case of no blocking, the multi-photon state population gradually increases as the pump laser power increases (see fig. 3 and 4), at which time the idler false alarm rate begins to increase as the multi-photon state increases. The quantum blocking effect is introduced into an idler optical path, so that only single photons can pass through and multiple photons cannot pass through. Therefore, once the idler photodetector detects the optical signal, it must be a single photon signal. Since the signal light and the idler light are always generated in pairs, it can be determined that the signal mode obtains a high quality single photon. Ideally, the prediction efficiency can reach one hundred percent when the idler quantum blockage induced by the N-type system is strong enough.
Of particular note, the present invention may allow for a gradual increase in pump laser power without fear of increased probability of multiphoton emission. Because in the situation that does not block, the increase of pumping power leads to the increase of multiphoton emission probability thereby reduces the problem that the idle detector forecast efficiency finally leads to signal mode single photon purity to descend the utility model discloses in can be avoided totally. Due to the quantum blockage introduced into the idler optical path, the idler optical multi-photon state cannot be transmitted, so that the single photon emission is picked out and the multi-photon emission is thrown away equivalently in post-selectivity. Therefore, even if the multi-photon emission probability is increased due to the increase of the pumping power, the multi-photon emission is abandoned in the post selection, and the single photon emission is selectively forecasted by the idler frequency detector, so that the single photon forecasting efficiency is greatly improved. The utility model discloses can combine all forecast single photon systems at present, for example, the spontaneous parameter down-conversion forecast single photon system of chamber reinforcing improves idle frequency light forecast efficiency.
Drawings
FIG. 1: figure 1 is a diagram of a high efficiency predictive single photon system.
Element number description:
1-1,1-3: the concave surface of the optical planoconcave mirror is plated with a reflecting film aiming at the parametric light, the reflectivity is more than 99.9 percent, the plane is plated with an antireflection film aiming at the parametric light, and the transmissivity is more than 99.8 percent.
1-2,1-4: the concave surface of the optical planoconcave mirror is plated with a reflecting film aiming at the parametric light, the reflectivity reaches 96% -98%, the plane is plated with an antireflection film aiming at the parametric light, and the transmittance is more than 99.8%.
1-1,1-2: the optical plano-concave mirror, the concave surface and the plane are coated with antireflection films aiming at the pump laser, and the transmissivity is more than 99.5%.
2-1,2-2: two end faces of the PPKTP crystal are plated with antireflection films aiming at the pump laser and the parametric light. The transmission for pump laser light is greater than 99.5%, and for parametric light, the transmission is greater than 99.8%.
3: and a dichroic mirror for reflecting the pump laser, transmitting the idler beam and the signal beam, and separating the pump laser from the emitted idler beam and the signal beam.
4: and the polarization beam splitter reflects the vertical polarization signal light and transmits the horizontal polarization idler frequency light.
4-1,4-2: the horizontal end face of the polarization beam splitter is plated with an antireflection film for the parametric light, and the transmission rate of the parametric light is greater than 99.8%.
5: atomic bubbles or solid quantum spins such as diamond color center defects provide an N-type atomic system. And strong idler frequency optical Kerr nonlinearity is generated under the control of control light.
5-1,5-2: two end faces of the rubidium atom bubbles are plated with antireflection films aiming at idler frequency light, the transmissivity is greater than 99.8%, and the idler frequency light can pass through the end faces and enter and exit the atom bubbles.
6-1,6-2: and the reflector is used for adjusting the light path of the control light, so that the control light, the atomic bubbles and the beam waist of the optical cavity form a small angle of 3-5 degrees and pass through the atomic bubbles.
And 7, a filtering device for filtering the extremely small amount of control light scattered into the idler frequency light channel.
8: the idle frequency light single photon detector and the signal light photon are subjected to coincidence measurement to generate a forecast single photon.
FIG. 2 is a drawing: FIG. 2 is a diagram of the coupling energy levels of the second cavity mode, control light and N-type atoms. The cavity mode resonating with the idler light is coupled to transitions 1 to 3, 2 to 4. Controlling the optical coupling transitions 2 to 3.
FIG. 3: FIG. 3 is a normalized photon pair population at low pump power 0.3 without blocking the idler. At the moment, the two-photon pair population is less than 0.009, and the single-photon pair population is 0.08. When the idler detector detects photons, the false alarm rate is low.
FIG. 4 is a drawing: fig. 4 is a normalized photon pair population at high pump power 2 without blocking the idler. At this time, the multi-photon pair population is rapidly increased, the two-photon pair population is 0.08, and the single-photon pair population is 0.12. When the idler detector detects photons, the false alarm rate is high.
Detailed Description
Example 1 high efficiency forecasting Single photon Source Using rubidium atom bubbles to block Idle photons
In conjunction with the system diagram, this example is embodied as follows:
(1) two sets of high-quality optical micro-cavities are built by four plano-concave reflectors. The mirror passes. The plane of the mirror 1-3 is plated with an anti-reflection film of 795nm, so that the plane of the idler frequency light which can pass through the plane 1-1 and the plane 1-2 is plated with an anti-reflection film for the wavelength of 397.5nm, the concave surface is also plated with an anti-reflection film for the wavelength of 397.5nm, and pumping laser can pass through without loss. The concave surfaces of the four mirrors are plated with high-reflection films for light with the wavelength of 795 nm.
(2) The concave reflectivity of mirrors 1-1 and 1-3 is up to 99.9% for light having a wavelength of 795nm, and the concave reflectivity of mirrors 1-2 and 1-4 is relatively low, about 96-98%. Meanwhile, the planes of the mirrors 1-2 and 1-4 are coated with antireflection films for light with the wavelength of 795 nm. Idler and signal light may exit from 1-2, as may idler light through mirrors 1-4.
(3) Two end faces of the PPKTP crystal are plated with anti-reflection films of 795 nm.
(4) The pump laser enters the optical microcavity through the mirror, and then idler frequency light and signal light with the same frequency and orthogonal polarization are generated through the conversion process under the spontaneous parameter of the PPKTP crystal.
(5) The idler and signal light exit from mirror 1-2 through a dichroic mirror 3 to separate the pump laser light.
(6) And two end faces of the polarization beam splitter are coated with anti-reflection films of 795 nm. The vertically polarized signal light is vertically reflected by the polarization beam splitter, while the horizontally polarized idler light passes through.
(7) The passed idler passes through mirror 1-3 into the second optical cavity.
(8) Two end faces of each rubidium atom glass bubble are plated with anti-reflection films of 795nm, and idle frequency light can enter and exit the atom bubbles through the end faces.
(9) And a high-permeability magnetic shielding material such as mu metal is wrapped around the rubidium atom bubbles.
(10) The reflectivity of the mirror 6-1 and 6-2 is more than 99.8 percent. The axis formed by the two mirrors is at a slight angle of about 3-5 degrees to the axis of the atomic bubble and the cavity.
(10) The laser is controlled to introduce and remove atomic bubbles through the mirror. And the beam waist is controlled to be larger than the beam waist of the optical cavity in the atomic bubble.
(11) And controlling laser to regulate and control strong Kerr nonlinearity of the atom generated idler frequency light. The density of atomic gas is controlled by adjusting the temperature of atomic bubbles, parameters such as light and atomic detuning are controlled, so that Kerr nonlinearity is far larger than the attenuation rate of an optical cavity, namely the line width, quantum photon blocking of the idler is realized, transmission of multiple photon states of the idler is prevented, and only single photon states are allowed to pass.
(12) The light and the idler frequency light are controlled to pass through the atomic gas in the same direction, and the micro Doppler effect caused by random thermal motion of atoms is eliminated.
(13) The N-type energy level system relates to the linear energy level arrangement of rubidium atoms D1 as follows:
,
,
,
。
the idler is horizontally polarized, coupling the two transitions 1 to 3 and 2 to 4, and the left-handed circular polarization controls the optical coupling transitions 2 to 3. In such an arrangement, multiple photon states are blocked and only a single photon can pass due to the quantum blocking effect introduced in the idler path, and thus must be a single photon once a photon is detected by the idler detector. Since the idler and signal lights are always generated in pairs, the signal mode must be a single photon state at this time. The forecasting efficiency can almost reach hundred percent forecasting under ideal quantum blockage.
Example 2 high efficiency predictive Single photon Source with Cavity enhancement Using Cesium atomic bubbles
And cesium atoms D1 are adopted to block idler frequency light, so that the corresponding pump laser wavelength needs to be selected to be 447.3nm, and an antireflection film plated for the pump laser is also selected to be 447.3 nm. The generated signal and idler were 894.6nm, and films plated for signal and idler were also selected at 894.6 nm. Involving cesium atoms having transition energy levels of
，
，
,
. The idler at 894.6nm couples the two transitions 1 to 3 and 2 to 4 optically, and the left hand circular polarization at 894.6nm controls the optical coupling transitions 2 to 3.
Example 3 high efficiency prediction of Single photon Source Using silicon color center Defect in Diamond
In this implementation, the solid-state diamond film needs to be cooled to a low temperature of 4K, and the silicon color center defects with one negative charge act as an N-type energy level system. Similar to example 2, the pump laser wavelength needs to be adjusted to 369nm, the signal light and idler light generated by the PPKTP crystal have a wavelength of 738nm, and the operating wavelengths of the corresponding antireflection film and reflection film need to be adjusted to 369nm and 738 nm. The transition energy level corresponding to the silicon color center defect is
，
，
. The horizontal polarization idler of 738nm couples the two transitions 1 to 3 and 2 to 4 optically, and the right-hand circular polarization with a wavelength of 738nm controls the optical coupling transitions 2 to 3.
The foregoing has described the principles, system architecture and implementation examples of the present invention in connection with the accompanying drawings. The present invention is not limited to the above system configurations and specific embodiments, and the embodiments in the specification are given only for the specific implementation and are intended to be illustrative and not limiting. The system structure can be adjusted according to the proposed principle, and different energy level structures and the generation and improvement modes of the predictive single photon source can be selected according to the needs by those skilled in the art under the teaching of the present invention. The present invention provides a method for improving single photon prediction by quantum photon blocking effect, which can be implemented in various forms without departing from the scope of the present invention.
Claims (10)
1. A high-efficiency forecasting single photon system introducing quantum blockage into an idler frequency optical path is characterized in that in a forecasting single photon system, after signal light and idler frequency light are emitted, a high-quality optical microcavity is added in the idler frequency optical path, N-type atomic gas is added into the cavity, and strong Kerr optical nonlinearity aiming at idler frequency photons is generated by utilizing quantum regulation atomic gas to realize the blockage of idler frequency multi-photon states, so that the efficiency of an idler frequency detector for forecasting the single photon is improved.
2. The high efficiency optically predictive system of claim 1, wherein the PPKTP nonlinear crystal illuminated by the pump laser produces two orthogonal modes of polarization of the parametric light, an idler and a signal.
3. The high efficiency, predictive light subsystem of claim 1, wherein the PPKTP nonlinear crystal periodic domain structure satisfies type II quasiphase matching conditions.
4. The high efficiency, proof light subsystem of claim 1, wherein both end faces of the PPKTP nonlinear crystal are coated with anti-reflective coatings for the pump light and the parametric light wavelengths.
5. The high efficiency, predictive single-photon system of claim 1, in which the four mirrors form two sets of high quality optical microcavities, one of which is configured to produce orthogonally polarized idler and signal light, and the other of which is configured to block transmission of idler multiple photon states.
6. The high efficiency forecasting subsystem as claimed in claim 1, wherein the first set of reflectors have a low reflectivity at the exit end, and the idler and signal lights exit through the reflectors; the second set of mirrors has a low reflectivity at the exit end, and idler light exits through the mirrors and is measured by a single photon detector.
7. The high efficiency forecasting light subsystem as claimed in claim 1, wherein the signal light is reflected off a polarizing beam splitter.
8. The high efficiency forecasting subsystem as claimed in claim 1, wherein the control laser is introduced into the atomic gas through two mirrors with small angles of 3-5 degrees with the optical cavity axis to induce atoms to generate strong kerr optical nonlinear effect on the idler optical field.
9. The high efficiency, forecasting light subsystem as claimed in claim 1, wherein the control light is filtered out at the idler exit port by a narrow band filter, allowing only the idler to pass through.
10. The high efficiency forecasting mono-light subsystem as claimed in claim 1, wherein the parametric down-conversion photon generation means and the photon blocking are implemented by two subsystems, respectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021909979.1U CN213092083U (en) | 2020-09-04 | 2020-09-04 | High-efficiency forecasting single-photon system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021909979.1U CN213092083U (en) | 2020-09-04 | 2020-09-04 | High-efficiency forecasting single-photon system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN213092083U true CN213092083U (en) | 2021-04-30 |
Family
ID=75634751
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202021909979.1U Active CN213092083U (en) | 2020-09-04 | 2020-09-04 | High-efficiency forecasting single-photon system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN213092083U (en) |
-
2020
- 2020-09-04 CN CN202021909979.1U patent/CN213092083U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Cohen et al. | Tailored photon-pair generation in optical fibers | |
| CN110568693B (en) | Forecasting single photon generation system and method | |
| US20060169877A1 (en) | Quantum computer and quantum computation method | |
| CA2680245A1 (en) | Generation of quantum-correlated and/or polarization-entangled photon pairs with unequal wavelengths | |
| CN103022888A (en) | Alkali metal steam laser of polarized optical pumping | |
| JP2004515825A (en) | Optical resonant frequency converter | |
| US9774162B2 (en) | Potassium fluoroboratoberyllate crystal oblique-incidence laser second harmonic generator | |
| CN213092083U (en) | High-efficiency forecasting single-photon system | |
| Mohammed et al. | Selective excitation of the TE/sub 01/mode in hollow-glass waveguide using a subwavelength grating | |
| CN101272033B (en) | Ring shaped resonance cavity laser | |
| CN112114462A (en) | System and method for efficiently forecasting single photons | |
| CN210005836U (en) | Compact single crystal thin cavity and entangled photon source system using the same | |
| Castelletto et al. | Two-photon mode preparation and matching efficiency: definition, measurement, and optimization | |
| CN110308603A (en) | Bicolor-code photon source generation module and double compatible communication devices including the module | |
| CN115390335B (en) | Compensation device of quantum entanglement source | |
| CN201345494Y (en) | OPO laser | |
| CN209658592U (en) | Self-frequency-doubling laser generating device and laser | |
| WO2011123822A2 (en) | Apparatus and method for generating continuous wave ultraviolet light | |
| RU76509U1 (en) | LASER WITH OPTICAL PARAMETRIC GENERATOR | |
| Zhou et al. | Highly Directional Radiation from Photonic Crystal Slabs | |
| Wang et al. | Nonlinear mirror with all-dielectric metasurface | |
| CN109683425A (en) | It is a kind of to polarize unrelated photon frequency conversion quantum devices | |
| CN111897135A (en) | Method for generating 180nm-290nm deep ultraviolet light | |
| Spektor et al. | Beamforming via wrapped transverse propagation for visible integrated photonics | |
| Talker et al. | Efficient hyperfine optical pumping of Rb atoms in Miniaturized vapor cells |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |