CN116387945B - Single photon source with adjustable photon service life - Google Patents

Single photon source with adjustable photon service life Download PDF

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CN116387945B
CN116387945B CN202310348386.4A CN202310348386A CN116387945B CN 116387945 B CN116387945 B CN 116387945B CN 202310348386 A CN202310348386 A CN 202310348386A CN 116387945 B CN116387945 B CN 116387945B
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micro
resonant cavity
ring
waveguide
ring resonant
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CN116387945A (en
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徐竞
王子杰
陈诺
张新亮
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Huazhong University of Science and Technology
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Huazhong University of Science and Technology
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
    • H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
    • H01S3/06—Construction or shape of active medium
    • H01S3/0627—Construction or shape of active medium the resonator being monolithic, e.g. microlaser

Abstract

The invention provides a single photon source with adjustable photon service life, comprising; the first micro-ring resonant cavity and the second micro-ring resonant cavity are directly coupled; the radius of the first micro-ring resonant cavity is half of that of the second micro-ring resonant cavity; the waveguide is coupled with the first micro-ring resonant cavity or the second micro-ring resonant cavity, or the second micro-ring resonant cavity can be coupled with a waveguide; the second micro-ring resonant cavity is used for resonating pump light, and under the action of spontaneous four-wave mixing, the signal light and idler frequency light wavelengths spontaneously generate photon pairs; the micro-ring resonant cavity is provided with tuning electrodes for controlling the alignment of resonant peaks of the two micro-ring resonant cavities, so that the bandwidths of the second micro-ring resonant cavity in the signal light and the idler frequency light resonant peaks are controlled, and the service lives of emitted photons are further controlled; when the two resonant cavities are not aligned, the service life of photons is only influenced by the resonance peak line width of the second micro-ring resonant cavity; in the process of gradually aligning the resonance peaks of the two micro-ring resonance cavities, the resonance peak of the second micro-ring resonance cavity is gradually widened, and the photon service life is gradually shortened.

Description

Single photon source with adjustable photon service life
Technical Field
The invention belongs to the field of quantum optics, and particularly relates to a single photon source with adjustable photon lifetime.
Background
The lifetime of a single photon or photon coherence time is an important property of a single photon. Single photons of different lifetimes have different applications in different integrated quantum technologies. A single photon light source with adjustable photon lifetime has important application in the light quantum technology, and a single photon source with adjustable photon lifetime based on a micro-ring resonant cavity is an integral part of the integrated light quantum technology. However, the conventional single photon source based on the micro-ring has a problem that the photon lifetime of the signal photons and idler photons generated in the micro-ring is only related to the ring path transmission coefficient of the micro-ring resonant cavity under the critical coupling condition, and the parameter cannot be conveniently adjusted in practical use, so that the photon lifetime of the single photon source is fixed. The position of the resonance peak of the micro-ring system can be adjusted by changing the spectrum structure of the micro-ring resonant cavity, and the bandwidth of the micro-ring system is controlled by utilizing the superposition of the resonance peaks of the two micro-ring resonant cavities, so that the photon service lives of the signal light photons and the idler light photons are regulated and controlled.
The single photon source with adjustable photon service life has important practical significance, and the output photon service life can be adjusted in a large range by simply adding an electrode to one micro-ring resonant cavity to adjust the resonance peak wavelength. Compared with the traditional photon emitter, the capacity of regulating the service life of photons can accurately and greatly control the pulse width of single photon pulses, and guarantees the subsequent realization of quantum operation by single photons. By utilizing the micro-ring resonant cavity, a beam of pulse pump light is coupled into the ring, under the action of the spontaneous four-wave mixing effect, a pair of signal photons and idler photons are spontaneously generated at the position where the frequency domain is symmetrical to the pump light, and the bandwidth of the signal photons and idler photons is completely regulated and controlled by the resonance peak of the micro-ring resonant cavity, as shown in figure 1; by utilizing the property, the photon life of the signal photons and the idler photons can be controlled by adjusting the resonance peak of the micro-ring resonant cavity.
In a single micro-ring resonator structure, the resonance peak of the idler light has the same width due to the resonance peak of the pump light and the signal light, and this width is determined by the coupling coefficients of the single waveguide and the ring. Therefore, when the resonance peak widths of the signal light and the idler light are adjusted, the resonance peak bandwidth of the pump light is also necessarily adjusted, and therefore the photon lives of the signal photons and the idler photons cannot be adjusted under the condition that the pump light is unchanged.
In existing on-chip nonlinear process-based single photon source schemes with adjustable photon lifetime, there are several methods to achieve efficient lifetime-adjusting operation. In a nonlinear single photon source based on a waveguide, photons are directly generated in the waveguide due to the absence of micro-ring and waveguide coupling, so that the photon lifetime is directly regulated by the photon lifetime of the pump light and the properties of the waveguide itself, without loss approximation. However, since there is no resonant structure in the waveguide, the density of pump photons is very small, resulting in very weak nonlinear effects, and thus a high brightness, high photon yield, tunable photon lifetime light source cannot be realized. The announced light source based on the micro-ring resonant cavity benefits from the extremely large field enhancement effect of the micro-ring, and the photon yield can be higher than that of the waveguide by several orders of magnitude, so that the announced light source has practical significance. In contrast, implementing a single photon source capable of lifetime tuning in a micro-ring resonator is of greater application value than experiments in waveguides.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a single photon source with adjustable photon life, and aims to solve the problem of fixed photon life in the single photon source based on spontaneous nonlinear process.
To achieve the above object, in a first aspect, the present invention provides a single photon source with adjustable photon lifetime, comprising: the waveguide, the first micro-ring resonant cavity and the second micro-ring resonant cavity;
the waveguide is coupled with the first micro-ring resonant cavity, and the second micro-ring resonant cavity is coupled with the first micro-ring resonant cavity;
the radius of the first micro-ring resonant cavity is half of that of the second micro-ring resonant cavity, so that the resonant peak interval of the first micro-ring resonant cavity is twice of that of the second micro-ring resonant cavity; setting the resonance peak of the first micro-ring resonant cavity as a first resonance peak, and setting the resonance peak of the second micro-ring resonant cavity as a second resonance peak;
an electrode is arranged on the first micro-ring resonant cavity or the second micro-ring resonant cavity, after a first resonant peak and a second resonant peak are aligned by using electric modulation through the electrode, an independent second resonant peak exists between every two pairs of aligned resonant peaks, the full width at half maximum of the aligned resonant peaks is larger than the full width at half maximum of the independent second resonant peaks, the aligned resonant peaks are respectively regarded as a wide resonant peak and a narrow resonant peak, then pump light is input to one side of a waveguide at the narrow resonant peak, signal light photons and idler light photons are spontaneously generated at the wide resonant peak, and the signal light photons and the idler light photons are coupled into the waveguide and output from the other side of the waveguide as a single photon source;
The service life of the single photon source is adjustable, the adjusting mode comprises a coarse adjusting part and a fine adjusting part, and the coarse adjusting part comprises the following steps: aligning the first resonance peak and the second resonance peak by using the electrode to widen the aligned resonance peak, wherein the better the first resonance peak is aligned with the second resonance peak, the wider the bandwidth of the wide resonance peak is; fine adjustment is as follows: after obtaining a wide resonance peak, controlling the intrinsic loss of the two micro-ring resonant cavities and the coupling coefficient of the waveguide and the first micro-ring resonant cavity to finely adjust the bandwidth of the wide resonance peak, wherein the wider the bandwidth of the wide resonance peak is, the shorter the service lives of signal light photons and idler frequency light photons generated at the wide resonance peak are; the bandwidth of the wide resonance peak is comprehensively regulated and controlled by two modes of coarse regulation and fine regulation so as to control the service life of photons of the single photon source.
Optionally, the coupling coefficient of the first micro-ring resonant cavity and the waveguide is set as a first coupling coefficient, and the coupling coefficient of the second micro-ring resonant cavity and the first micro-ring resonant cavity is set as a second coupling coefficient;
the first coupling coefficient and the second coupling coefficient are controlled to enable the resonant cavity system to be in critical coupling with the waveguide at the narrow resonance peak, so that the generation efficiency of signal light photons and idler frequency light photons at the wide resonance peak is improved;
the first micro-ring resonant cavity and the second micro-ring resonant cavity form a resonant cavity system, the waveguide is in a critical coupling state with the micro-ring resonant cavity system at a narrow resonant peak, so that pump light input to the waveguide at the narrow resonant peak is completely coupled into the first micro-ring resonant cavity and the second micro-ring resonant cavity, and resonance is built in the second micro-ring resonant cavity;
The waveguide is in a critical coupling state with the micro-ring resonant cavity system at a narrow resonance peak, and specifically comprises the following steps: and adjusting the first coupling coefficient by adjusting the distance between the waveguide and the first micro-ring resonant cavity so that the coupling loss introduced by the waveguide is equal to the sum of the intrinsic loss of the first micro-ring resonant cavity and the intrinsic loss of the second micro-ring resonant cavity.
Optionally, the fine adjustment is: after the control waveguide is in a critical coupling state with the micro-ring resonant cavity system at the narrow resonance peak, when the first coupling coefficient or/and the intrinsic loss of the first micro-ring resonant cavity are increased, the bandwidth of the wide resonance peak is increased.
In a second aspect, the present invention provides a single photon source of adjustable photon lifetime comprising: the first micro-ring resonant cavity, the second micro-ring resonant cavity and the waveguide;
the first micro-ring resonant cavity is coupled with the second micro-ring resonant cavity, the waveguide is coupled with the second micro-ring resonant cavity,
the radius of the first micro-ring resonant cavity is half of that of the second micro-ring resonant cavity, so that the resonant peak interval of the first micro-ring resonant cavity is twice of that of the second micro-ring resonant cavity; setting the resonance peak of the first micro-ring resonant cavity as a first resonance peak, and setting the resonance peak of the second micro-ring resonant cavity as a second resonance peak;
An electrode is arranged on the first micro-ring resonant cavity or the second micro-ring resonant cavity, after a first resonant peak and a second resonant peak are aligned by using electric modulation through the electrode, an independent second resonant peak exists between every two pairs of aligned resonant peaks, the full width at half maximum of the aligned resonant peaks is larger than the full width at half maximum of the independent second resonant peaks, the aligned resonant peaks are respectively regarded as a wide resonant peak and a narrow resonant peak, then pump light is input to one side of a waveguide at the narrow resonant peak, signal light photons and idler light photons are spontaneously generated at the wide resonant peak, and the signal light photons and the idler light photons are coupled into the waveguide and output from the other side of the waveguide as a single photon source;
the service life of the single photon source is adjustable, the adjusting mode comprises a coarse adjusting part and a fine adjusting part, and the coarse adjusting part comprises the following steps: aligning the first resonance peak and the second resonance peak by using the electrode to widen the aligned resonance peak, wherein the better the first resonance peak is aligned with the second resonance peak, the wider the bandwidth of the wide resonance peak is; fine adjustment is as follows: after obtaining a wide resonance peak, controlling the intrinsic loss of the two micro-ring resonant cavities and the coupling coefficient of the waveguide and the second micro-ring resonant cavity to finely adjust the bandwidth of the wide resonance peak, wherein the wider the bandwidth of the wide resonance peak is, the shorter the service lives of signal light photons and idler frequency light photons generated at the wide resonance peak are; the bandwidth of the wide resonance peak is comprehensively regulated and controlled by two modes of coarse regulation and fine regulation so as to control the service life of photons of the single photon source.
Optionally, the coupling coefficient of the second micro-ring resonant cavity and the waveguide is set as a first coupling coefficient, and the coupling coefficient of the second micro-ring resonant cavity and the first micro-ring resonant cavity is set as a second coupling coefficient;
the first coupling coefficient and the second coupling coefficient are controlled to enable the resonant cavity system to be in critical coupling with the waveguide at the narrow resonance peak, so that the generation efficiency of signal light photons and idler frequency light photons at the wide resonance peak is improved;
the first micro-ring resonant cavity and the second micro-ring resonant cavity form a resonant cavity system, the waveguide is in a critical coupling state with the micro-ring resonant cavity system at a narrow resonant peak, so that pump light input to the waveguide at the narrow resonant peak is completely coupled into the first micro-ring resonant cavity and the second micro-ring resonant cavity, and resonance is built in the second micro-ring resonant cavity;
the waveguide is in a critical coupling state with the micro-ring resonant cavity system at a narrow resonance peak, and specifically comprises the following steps: and adjusting the first coupling coefficient by adjusting the distance between the waveguide and the second micro-ring resonant cavity so that the coupling loss introduced by the waveguide is equal to the sum of the intrinsic loss of the first micro-ring resonant cavity and the intrinsic loss of the second micro-ring resonant cavity.
Optionally, the fine adjustment is: after the control waveguide is in a critical coupling state with the micro-ring resonant cavity system at the narrow resonance peak, when the first coupling coefficient or/and the intrinsic loss of the first micro-ring resonant cavity are increased, the bandwidth of the wide resonance peak is increased.
In a third aspect, the present invention provides a single photon source of adjustable photon lifetime comprising: the first waveguide, the first micro-ring resonant cavity, the second micro-ring resonant cavity and the second waveguide;
the first waveguide is coupled with the first micro-ring resonant cavity, the first micro-ring resonant cavity is coupled with the second micro-ring resonant cavity, and the second micro-ring resonant cavity is coupled with the second waveguide;
the radius of the first micro-ring resonant cavity is half of that of the second micro-ring resonant cavity, so that the resonant peak interval of the first micro-ring resonant cavity is twice of that of the second micro-ring resonant cavity; setting the resonance peak of the first micro-ring resonant cavity as a first resonance peak, and setting the resonance peak of the second micro-ring resonant cavity as a second resonance peak;
an electrode is arranged on the first micro-ring resonant cavity or the second micro-ring resonant cavity, after a first resonant peak and a second resonant peak are aligned by using an electric regulator through the electrode, an independent second resonant peak exists between every two pairs of aligned resonant peaks, the full width at half maximum of the aligned resonant peaks is larger than the full width at half maximum of the independent second resonant peaks, the aligned resonant peaks are respectively regarded as a wide resonant peak and a narrow resonant peak, then pump light is input to one side of a preset waveguide at the narrow resonant peak, signal light photons and idler light photons are spontaneously generated at the wide resonant peak, and the signal light photons and the idler light photons are coupled into the waveguide and output from the other side of the preset waveguide as a single photon source; the preset waveguide is a first waveguide or a second waveguide;
The service life of the single photon source is adjustable, the adjusting mode comprises a coarse adjusting part and a fine adjusting part, and the coarse adjusting part comprises the following steps: aligning the first resonance peak and the second resonance peak by using the electrode to widen the aligned resonance peak, wherein the better the first resonance peak is aligned with the second resonance peak, the wider the bandwidth of the wide resonance peak is; fine adjustment is as follows: after obtaining a wide resonance peak, controlling the intrinsic loss of the two micro-ring resonant cavities and the coupling coefficient of the preset waveguide and the micro-ring resonant cavities to finely adjust the bandwidth of the wide resonance peak, wherein the wider the bandwidth of the wide resonance peak is, the shorter the service lives of signal light photons and idler light photons generated at the wide resonance peak are; the bandwidth of the wide resonance peak is comprehensively regulated and controlled by two modes of coarse regulation and fine regulation so as to control the service life of photons of the single photon source.
Optionally, the coupling coefficient of the first micro-ring resonant cavity and the first waveguide is set as a first coupling coefficient, the coupling coefficient of the second micro-ring resonant cavity and the first micro-ring resonant cavity is set as a second coupling coefficient, and the coupling coefficient of the second micro-ring resonant cavity and the second waveguide is set as a third coupling coefficient;
when pump light is input from the first waveguide, the first coupling coefficient and the second coupling coefficient are controlled to enable the resonant cavity system to be in critical coupling with the first waveguide at a narrow resonance peak, so that the generation efficiency of signal light photons and idler frequency light photons at a wide resonance peak is improved; the first micro-ring resonant cavity and the second micro-ring resonant cavity form a resonant cavity system, the first waveguide is in a critical coupling state with the micro-ring resonant cavity system at a narrow resonant peak, so that pump light input to the first waveguide at the narrow resonant peak is completely coupled into the first micro-ring resonant cavity and the second micro-ring resonant cavity, and resonance is built in the second micro-ring resonant cavity;
The first waveguide is in a critical coupling state with the micro-ring resonant cavity system at a narrow resonance peak, and specifically comprises the following steps: and adjusting the first coupling coefficient by adjusting the distance between the first waveguide and the first micro-ring resonant cavity, so that the coupling loss introduced by the first waveguide is equal to the sum of the intrinsic loss of the first micro-ring resonant cavity, the intrinsic loss of the second micro-ring resonant cavity and the coupling loss introduced by the second waveguide.
Optionally, when the pump light is input from the second waveguide, the first coupling coefficient and the second coupling coefficient are controlled to enable the resonant cavity system to be in critical coupling with the second waveguide at the narrow resonance peak, so that the generation efficiency of the signal light photons and the idler light photons at the wide resonance peak is improved; the first micro-ring resonant cavity and the second micro-ring resonant cavity form a resonant cavity system, the second waveguide is in a critical coupling state with the micro-ring resonant cavity system at a narrow resonant peak, so that pump light input to the second waveguide at the narrow resonant peak is completely coupled into the first micro-ring resonant cavity and the second micro-ring resonant cavity, and resonance is built in the second micro-ring resonant cavity;
the second waveguide is in a critical coupling state with the micro-ring resonant cavity system at a narrow resonance peak, and specifically comprises the following steps: and adjusting a third coupling coefficient by adjusting the distance between the second waveguide and the second micro-ring resonant cavity, so that the coupling loss introduced by the second waveguide is equal to the sum of the intrinsic loss of the first micro-ring resonant cavity, the intrinsic loss of the second micro-ring resonant cavity and the coupling loss introduced by the first waveguide.
Optionally, the fine adjustment is: after the preset waveguide is controlled to be in a critical coupling state with the micro-ring resonant cavity system at the narrow resonance peak, when the third coupling coefficient or/and the intrinsic loss of the first micro-ring resonant cavity or/and the first coupling coefficient is/are increased, the bandwidth of the wide resonance peak is increased.
The coupling coefficient of the waveguide which is not used as an input/output is increased, and the intrinsic loss of the micro-ring resonator which corresponds to the coupling of the waveguide is increased. Thus, the intrinsic loss of the micro-ring can be adjusted by the corresponding coupling coefficient.
In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:
the invention provides a single photon source with adjustable photon service life, which can generate resonance in a second micro-ring resonant cavity by input pump light and cannot generate resonance in a first micro-ring resonant cavity. The signal light and the idler light can generate resonance in the second micro-ring resonant cavity, and cannot resonate in the first micro-ring resonant cavity. At this time, an electrode is added on the first micro-ring resonant cavity, and the position of the resonant peak of the first micro-ring resonant cavity is controlled by utilizing electric control, so that the aim of controlling the coupling of the resonant peaks of the two micro-ring resonant cavities is fulfilled. At this time, due to the field enhancement effect of the micro-ring resonator, the rate of signal photons and idler photons generation is increased compared to the waveguide. Meanwhile, due to the fact that the resonance peaks of the two micro-ring resonant cavities are coupled, the width of the resonance peaks is increased, the service life of photons is reduced, the bandwidths of signal light and idler frequency light can be further adjusted through adjusting and controlling the first coupling coefficient and the intrinsic loss of the micro-ring resonant cavities, the second micro-ring resonant cavities can be further coupled with one waveguide, and the bandwidth of pump light can be adjusted through further adjusting the coupling of the second micro-ring resonant cavities and the waveguide. The invention realizes the regulation and control of the output photon life, and becomes an effective single photon source with adjustable photon life.
The invention provides a single photon source with adjustable photon service life, which is based on a coupled structure of two micro-ring resonant cavities, wherein the micro-ring resonant cavities have smaller structures (generally radius is within micrometer scale), and can be better integrated on a chip compared with a highly nonlinear optical fiber structure (generally length is above hundred meters). In the invention, the first micro-ring resonant cavity, the second micro-ring resonant cavity and the waveguide are made of three-order nonlinear materials, the material loss is relatively low, and the power consumption can be reduced.
The invention provides a single photon source with adjustable photon service life, which comprises the following steps: powering on and adjusting the first micro-ring resonant cavity, so that the position of a resonant peak of the first micro-ring resonant cavity moves to couple with the resonant peak of the second micro-ring resonant cavity and generate the effect of stretching the resonant peak; the above-mentioned range of adjustment is such that the resonance peak has been coupled as one peak and is a stretched state compared to the original resonance peak; in this state, the lifetime of the output signal light and idler light photons can be effectively shortened and can be regulated and used for practical use.
Drawings
FIG. 1 is a schematic diagram of the principle of spontaneous four-wave mixing provided by the prior art;
FIG. 2 is a schematic diagram of a coupling structure of two micro-ring resonators and a waveguide according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of another embodiment of the present invention for coupling two micro-ring resonators to a waveguide;
FIG. 4 is a schematic diagram of a coupling structure of two micro-ring resonators and two waveguides provided by an embodiment of the present invention;
FIG. 5 is a graph of the intensity of the transmission spectrum of the waveguide output end provided by an embodiment of the present invention when the resonant peaks are aligned;
FIG. 6 is a graph of the intensity of the transmission spectrum of a waveguide output end provided by an embodiment of the present invention when the resonant peaks are not aligned;
fig. 7 is a flowchart of a photon lifetime adjustment method according to an embodiment of the present invention.
Detailed Description
For convenience of understanding, the following description will explain and describe english abbreviations and related technical terms related to the embodiments of the present application.
Embodiments of the present application are described below with reference to the accompanying drawings in the embodiments of the present application.
The invention provides a single photon source with adjustable photon service life, comprising; the first micro-ring resonant cavity and the second micro-ring resonant cavity are directly coupled; the radius of the first micro-ring resonant cavity is half of that of the second micro-ring resonant cavity; the waveguide is coupled with the first micro-ring resonant cavity, or coupled with the second micro-ring resonant cavity, or the second micro-ring resonant cavity can be coupled with a waveguide; the second micro-ring resonant cavity is used for resonating pump light, and under the action of spontaneous four-wave mixing, the signal light and idler frequency light wavelengths spontaneously generate photon pairs; the first micro-ring resonant cavity is provided with a tuning electrode which is used for controlling the alignment of a resonant peak with the second micro-ring resonant cavity so as to control the bandwidth of the second micro-ring resonant cavity in the signal light and the idler frequency light resonant peak and further control the service life of emitted photons; when the first micro-ring resonant cavity and the second micro-ring resonant cavity are not aligned, the service life of photons is only influenced by the resonance peak line width of the second micro-ring resonant cavity; in the process of aligning the first micro-ring resonant cavity with the second micro-ring resonant cavity, the resonant peak of the second micro-ring resonant cavity is gradually widened, and the photon service life is gradually shortened. According to the invention, the effect of regulating and controlling the service life of photons generated by a single photon source is achieved by regulating and controlling the resonance peak of the quantum light source based on the micro-ring resonant cavity.
Specifically, the first micro-ring resonant cavity is coupled with the second micro-ring resonant cavity, and the waveguide can be coupled with the first micro-ring resonant cavity or the second micro-ring resonant cavity; under the condition that the waveguide is coupled with the first micro-ring resonant cavity, the second micro-ring resonant cavity can be coupled with a waveguide; the radius of the first micro-ring resonant cavity is half of that of the second micro-ring resonant cavity, so that the resonance peak interval of the first micro-ring resonant cavity is twice of that of the second micro-ring resonant cavity, and when the resonance peaks of the second micro-ring resonant cavity and the resonance peaks of the first micro-ring resonant cavity are not overlapped, two resonance peaks of the second micro-ring resonant cavity are included between the resonance peaks of the two first micro-ring resonant cavities; and setting electrodes on the first micro-ring resonant cavity, aligning the resonant peak of the first micro-ring resonant cavity with the resonant peak of the second micro-ring resonant cavity by using electric tuning, wherein the second micro-ring resonant cavity has an overlapped resonant peak and a non-overlapped resonant peak, and the positions of the resonant peak of the first micro-ring resonant cavity and the overlapped resonant peak are the same, and one non-overlapped resonant peak exists between every two overlapped resonant peaks.
Pumping light is input to one side of the waveguide at a narrow resonance peak, signal light photons and idler frequency light photons are spontaneously generated at a wide resonance peak, the signal light photons and the idler frequency light photons are coupled into the waveguide, and the single photons with adjustable photon life are output from the other side of the waveguide; the intrinsic losses of the two micro-ring resonators are controlled, and the coupling coefficients of the waveguide and the first micro-ring resonator or the second micro-ring resonator are controlled to control the bandwidths of the wide resonance peak and the narrow resonance peak. The first micro-ring resonant cavity is provided with a tuning electrode to control the positions of the resonance peak of the first micro-ring resonant cavity and the resonance peak of the second micro-ring resonant cavity to be overlapped, and the bandwidth of the resonance peak of the second micro-ring resonant cavity is influenced by the resonance peak of the first micro-ring resonant cavity in the tuning process, so that the photon service lives of the signal light photons and the idler frequency light photons are controlled. The non-overlapping resonance peaks are narrow resonance peaks; the overlapped resonance peak is a wide resonance peak; the photon lifetime refers to the pulse width of a single photon in the time domain.
In an alternative example, the coupling coefficient of the first micro-ring resonator and the waveguide is a first coupling coefficient; the coupling coefficient of the first micro-ring resonant cavity and the second micro-ring resonant cavity is a second coupling coefficient; the coupling coefficient of the second micro-ring resonant cavity and the other waveguide is a third coupling coefficient.
The first coupling coefficient and the second coupling coefficient are controlled to enable the second micro-ring resonant cavity to be in critical coupling with the waveguide at the narrow resonance peak, so that the conversion efficiency of spontaneous four-wave mixing is improved, and the generation efficiency of signal light photons and idler frequency light photons at the wide resonance peak is improved.
In an alternative example, the first micro-ring resonant cavity and the second micro-ring resonant cavity form a resonant cavity system, the waveguide is in a critical coupling state with the micro-ring resonant cavity system at a narrow resonant peak, so that pump light input to the waveguide at the narrow resonant peak is completely coupled into the first micro-ring resonant cavity and the second micro-ring resonant cavity, and resonance is built in the second resonant cavity;
the waveguide is in a critical coupling state with the micro-ring resonant cavity system at a narrow resonance peak, and specifically comprises the following steps: and adjusting the first coupling coefficient by adjusting the distance between the waveguide and the first micro-ring resonant cavity so that the coupling loss introduced by the waveguide is equal to the sum of the intrinsic loss of the first micro-ring resonant cavity and the intrinsic loss of the second micro-ring resonant cavity. If the second waveguide is coupled with the second micro-ring resonant cavity, the coupling loss introduced by the first waveguide is equal to the sum of the intrinsic loss of the first micro-ring resonant cavity, the intrinsic loss of the second micro-ring resonant cavity and the coupling loss introduced by the second waveguide.
In an alternative example, the two resonance positions close to the resonance wavelength when the first micro-ring resonant cavity is not powered up are the first resonance positions; two resonance positions of the second micro-ring resonant cavity corresponding to the frequency of the signal light and the idler frequency light are second resonance positions; controlling the intrinsic loss of the first micro-ring resonant cavity, the intrinsic loss of the second micro-ring resonant cavity and the first coupling coefficient to adjust the bandwidth of the wide resonance peak; controlling the intrinsic loss and the third coupling coefficient of the second micro-ring resonant cavity to adjust the bandwidth of the narrow resonance peak;
the first resonance position and the second resonance position are electrically controlled to coincide, so that the resonance peak of the first micro-ring resonant cavity and the resonance peak of the second micro-ring resonant cavity are overlapped, the bandwidths of the signal light photons and the idler light photons are controlled, and the service lives of the signal light photons and the idler light photons are controlled.
After the control waveguide is in a critical coupling state with the micro-ring resonant cavity system at the narrow resonance peak, the bandwidth at the wide resonance peak is improved by increasing the first coupling coefficient and the intrinsic loss of the first micro-ring resonant cavity.
In an alternative example, the wavelengths of the signal light photons and idler light photons are symmetrical about the wavelength of the pump light;
The wavelength of the pump light is the wavelength corresponding to the narrow resonance peak; the wavelengths of the signal light photons and the idler light photons are the wavelengths corresponding to the wide resonance peaks; the wavelengths of the pump light, the signal light and the idler frequency light are all resonant wavelengths of the second micro-ring resonant cavity;
the pump light generates resonance in the second micro-ring resonant cavity, and cannot generate resonance in the first micro-ring resonant cavity; the signal light photons and idler light photons resonate within the first micro-ring resonator and the second micro-ring resonator.
The waveguide is used for inputting pump light, outputting signal light and idler frequency light; the first micro-ring resonant cavity is used for widening and adjusting the bandwidths of the signal light and idler light resonant peaks; the second micro-ring resonant cavity is used for resonating pump light, and signal light and idler frequency light are spontaneously generated under the action of spontaneous four-wave mixing;
wherein the wavelengths of the signal light and the idler light are symmetrical with respect to the wavelength of the pump light; the wavelength of the pump light is the wavelength corresponding to the resonance peak of the second micro-ring resonant cavity and is not the wavelength corresponding to the resonance peak of the first micro-ring resonant cavity; the wavelength of the signal light and the idler frequency light is the wavelength corresponding to the resonance peak coupling of the first micro-ring resonant cavity and the resonance peak coupling of the second micro-ring resonant cavity.
Preferably, the materials of the first micro-ring resonant cavity and the second micro-ring resonant cavity are three-order nonlinear materials.
Preferably, the method for acquiring the critical coupling state of the micro-ring resonant cavity system and the waveguide comprises the following steps:
and adjusting the first coupling coefficient by adjusting the distance between the waveguide and the first micro-ring resonant cavity so that the coupling loss introduced by the waveguide is equal to other residual loss.
Preferably, the electric tuning controls the resonance peak position of the first micro-ring resonant cavity to coincide with the resonance peak position of the second micro-ring resonant cavity, so that the resonance peak of the first micro-ring resonant cavity overlaps with the resonance peak of the second micro-ring resonant cavity.
Preferably, pump light is input to the waveguide at the narrow resonance peak, signal light photons and idler light photons are spontaneously generated at the widened resonance peak, the intrinsic loss of the micro-ring resonant cavity and the coupling coefficient of the waveguide and the micro-ring resonant cavity are controlled, the bandwidth of the resonance peak is controlled, the bandwidth of the widened resonance peak is far greater than that of the narrow resonance peak, the photon lives of the generated signal light photons and idler light photons are greatly shortened, and the photon lives can be regulated and controlled within a certain range through power-on regulation.
Preferably, the bandwidth (broad peak) of the coupled resonance peak can be controlled by controlling the intrinsic loss of the first micro-ring resonator and the intrinsic loss of the second resonator, and the first coupling coefficient; the intrinsic loss and the third coupling coefficient of the second micro-ring resonant cavity are controlled, so that the bandwidth of a resonance peak which is not coupled can be controlled; when the parameter setting meets the requirement of generating the pump light critical coupling, the signal light and idler frequency light resonance peaks can be widened by increasing the first coupling coefficient and the intrinsic loss of the first resonant cavity.
On the other hand, the invention provides a corresponding quantum photon generation method based on the single photon generation device with adjustable photon service life, which comprises the following steps:
inputting pump light into the second micro-ring resonant cavity for resonance enhancement, and improving the power in the second micro-ring resonant cavity;
under the action of spontaneous four-wave mixing, the signal light and the idler frequency light spontaneously generate signal photons and idler frequency photons in the second micro-ring resonant cavity based on the phase matching condition of the spontaneous four-wave mixing;
the signal light and the idler frequency light pass through the first micro-ring resonant cavity and are output by the output end of the waveguide;
the first micro-ring resonant cavity and the waveguide are in a critical coupling state, and a resonance peak of the first micro-ring resonant cavity is coupled with a resonance peak at the coupling wavelength of the second micro-ring resonant cavity; the radius of the first micro-ring resonant cavity is half of the radius of the second micro-ring resonant cavity;
the wavelengths of the signal light and the idler light are symmetrical with respect to the wavelength of the pump light; the wavelength of the pump light is the wavelength corresponding to the resonance peak of the second micro-ring resonant cavity and is not the wavelength corresponding to the resonance peak of the first micro-ring resonant cavity; the wavelength of the signal light and the idler frequency light is the wavelength corresponding to the resonance peak coupling of the first micro-ring resonant cavity and the resonance peak coupling of the second micro-ring resonant cavity.
Preferably, the method for obtaining the critical coupling state between the first micro-ring resonant cavity and the waveguide comprises the following steps:
and adjusting a first coupling coefficient by adjusting the distance between the waveguide and the first micro-ring resonant cavity, so that the coupling loss introduced by the waveguide is equal to other residual losses.
The invention adopts two different micro-ring resonant cavities to couple with each other, and adopts one waveguide to couple with the first micro-ring resonant cavity; the mutual coupling of the micro-ring resonant cavities, the effect brought by the waveguide on the coupling of the micro-ring resonant cavities and the coupling of the resonant peaks of the two micro-ring resonant cavities are utilized, the resonant peaks of the signal light and the idler light are regulated, the signal light and the idler light are widened, the high quality factor of the pumping resonant peak is not influenced, the efficiency of spontaneous four-wave mixing is ensured, the regulation and control on the service life of photons is realized, and therefore, the high-quality quantum light source with unique properties is successfully realized. The first micro-ring resonant cavity is provided with a heat regulating electrode, the coupling of the resonant peak is controlled by controlling heat regulation, and the resonant peak of the first micro-ring resonant cavity is utilized to influence the resonant peak of the second micro-ring resonant cavity so as to achieve the purpose of regulating and controlling the photon service life. Meanwhile, the high integration level and low power consumption of the system can well ensure that the system plays a role in integrated quantum application.
The single photon source generating device with adjustable photon service life provided by the invention has the following characteristics:
(1) The first micro-ring resonator and the second micro-ring resonator are different in size, and the perimeter of the first micro-ring resonator can be half of that of the second micro-ring resonator; at the same time, the lower the loss of the two micro-ring resonators is, the better, so as to ensure high photon generation efficiency.
(2) After power-on adjustment, the coupled signal light and idler frequency light resonance peaks ensure large bandwidth, so that the photon lives of the signal light photons and the idler frequency light photons can be greatly reduced.
(3) The coupling between the waveguide and the first resonant cavity is ensured to reach critical coupling; by regulating the coupling strength of the waveguide and the first resonant cavity, the coupling loss brought by the waveguide is approximately equal to the other overall losses of the system, and at the moment, critical coupling can be achieved, so that light input into the waveguide is basically extinction at the output port of the waveguide.
As an embodiment of the present invention, the first coupling coefficient and the second coupling coefficient are selected to ensure critical coupling of a narrow resonance peak, and the coupled resonance peak is widened; the first coupling coefficient refers to the coupling coefficient between the waveguide and the first micro-ring resonant cavity, and the second coupling coefficient refers to the coupling coefficient between the first micro-ring resonant cavity and the second micro-ring resonant cavity.
The single photon generating device with adjustable photon service life can be prepared according to the following method:
(1) According to the loss of the micro-ring resonant cavity, determining that the pump resonance peak is in a critical coupling state, for example, the extinction ratio of the pump resonance peak is required to be larger than 15dB;
(2) The coupling coefficient is determined according to the critical coupling state, for example, the coupling coefficient may be set as: the first coupling coefficient is 0.74, and the second coupling coefficient is 0.4;
(3) Determining the bandwidth of the signal light and the bandwidth of the idler frequency light according to the coupling coefficient, and determining that the bandwidth of a resonance peak of the signal light and the idler frequency light, which can be obtained by mode broadening, is larger than the bandwidth of a resonance peak of the pump light;
(4) And coupling the two first micro-ring resonant cavities with different sizes with the second micro-ring resonant cavity, and coupling the waveguide with the first micro-ring resonant cavity, thereby forming a double-resonant-cavity single-waveguide structure.
According to the single photon generating device with adjustable photon service life, a beam of pumping light which can resonate in the second resonant cavity but cannot resonate in the first micro-ring resonant cavity is input from one side of the waveguide coupled with the first micro-ring resonant cavity, and the wavelength of the generated signal light and the wavelength of the idler light are the wavelength corresponding to the coupling of the resonant peaks of the first micro-ring resonant cavity and the second micro-ring resonant cavity and are symmetrical about the pumping wavelength; because the critical coupling is achieved between the waveguide and the micro-ring resonant cavity system, the pump light is totally coupled into the second micro-ring resonant cavity, and the second resonant cavity is greatly enhanced in resonance, so that the power level in the second micro-ring resonant cavity is high, and the spontaneous four-wave mixing efficiency is high; in the first micro-ring resonant cavity, the pump light does not resonate, so that the pump light power is very low, and the spontaneous four-wave mixing process does not basically occur in the first resonant cavity;
According to the phase matching condition of spontaneous four-wave mixing, under the arrangement mode of the pump light, signal light can be generated at the signal light wavelength, idler light can be generated at the idler light wavelength, and the signal light wavelength and the idler light wavelength are symmetrical relative to the pump light wavelength; meanwhile, due to the arrangement mode of the spectrums, resonance peaks of the signal light and the idler frequency light are widened due to coupling of the two micro-ring resonant cavities, so that photon lives of the signal light and the idler frequency light are equivalently shortened.
The photon pair with adjustable photon life is very convenient to emit and design.
To further illustrate the advantages of the adjustable photon lifetime of the present invention over the generation device, a comparison analysis of the present invention with the prior art is now performed:
(1) Compared with a high-nonlinearity optical fiber system, the photon pair generating system provided by the invention comprises a double-resonant-cavity single-waveguide structure, and the resonance enhancement effect of the micro-ring resonant cavity is many times greater than that of the high-nonlinearity optical fiber system, so that the required material length is greatly reduced, the structure is more suitable for integration and miniaturization, and meanwhile, photon pair emission with adjustable photon service life can be realized without special dispersion management; and, there is a high nonlinearity of the integrated material platform.
(2) Compared with a waveguide structure, the photon pair generating system with adjustable photon service life can remarkably reduce power consumption by utilizing the resonance enhancement effect of the micro-ring resonant cavity, and the pumping resonance peak is in a critical coupling state and has the maximum nonlinear gain.
(3) The invention can well give consideration to the emission rate of photon pairs, the brightness of the light source and the emission of high-efficiency photon pairs, realizes the functionality and can be widely applied to quantum light sources.
(4) The invention solves the problem that the service life of single photon can not be regulated when the micro-ring resonant cavity is used for single photon source in structural design, and the structure can be applied to various integrated nonlinear material platforms and is not limited to a single material.
The principle of the spontaneous four-wave mixing to generate quantum photons is shown in figure 1 by using a double-resonant-cavity single-waveguide structure. By non-degenerate spontaneous four-wave mixing (SFWM), e.g. FIG. 1, a beam with a center frequency ω p Spontaneously transmitting energy to a frequency omega s And the signal light and frequency of (a) are omega i The frequencies of the signal light and the idler light are located on both sides of the pump light and are symmetrical with respect to the pump light. The frequency of the three beams of light meets 2 omega p ＝ω s +ω i 。
As shown in fig. 2, two micro-ring resonators having very low loss coefficients and different radii are used to couple to each other. According to the micro-ring resonance condition, when the wavelength of incident light meets the following condition When input light resonates within the microring resonator. Wherein m is the resonant order; n is n eff Is the effective refractive index of the material; l is the length of the micro-ring resonant cavity; the circumferences of the two micro-ring resonators in FIG. 2 are L respectively 1 ，L 2 The method comprises the steps of carrying out a first treatment on the surface of the Through selection of materials, selection of micro-ring radius and regulation and control of an external electrode, an aligned resonance peak is arranged between the two micro-ring resonant cavities, the circumference of the first micro-ring resonant cavity is required to be half of that of the second micro-ring resonant cavity, the aligned resonance peaks are mutually coupled, and corresponding wavelengths can reach a resonance state in the double rings at the same time.
As shown in fig. 3, alternatively, the coupling modes of the waveguides and the two micro-ring resonators may also be exchanged; as shown in fig. 4, a waveguide may be further connected to couple with the second micro-ring resonator based on fig. 2.
Generally, two micro-ring resonant cavities with the same materials and different radiuses can be selected. For example using n eff Material=2.45, L 1 ＝157um，L 2 Two rings of 314um at 1554.7nm are both resonant wavelengths of the two micro-ring resonators. Because of the different radii of the two microring resonators, there are some misaligned resonant peaks in the Free Spectral Range (FSR) at which the two microring resonators are not coupled and have minimal interaction, as shown by the resonant peaks in the middle of FIG. 5. Meanwhile, the circumferences of the two rings have a multiple relationship, so that the resonance peaks of the two rings are overlapped at regular intervals, and at the moment, the two micro-ring resonant cavities are in a coupling state, and the resonance peaks at the alignment position have large bandwidth and equivalent coupling coefficients due to the coupling effect, as shown by the resonance peaks at the left side and the right side of the graph in fig. 5.
In the case of using the resonance peak of the electrode regulation ring 1, the resonance peaks of both rings are deviated from each other, and a non-aligned resonance peak distribution occurs, as shown in the resonance peak distribution of fig. 6. The small ring resonance peak which is not aligned with the large ring resonance peak is gradually aligned with the large ring in the process of being tuned by the electrode, and the resonance peak of the large ring is gradually widened under the influence of the small ring resonance peak in the process, so that the service life of photons is gradually shortened. When the two ring formants are perfectly aligned, the formant distribution returns to the situation shown in FIG. 5 where the lifetime of the photon is minimized.
In the invention, the side coupling is performed through the waveguide and the micro-ring resonant cavity, and the specific steps are as follows: the waveguide coupled by the first micro-ring resonant cavity inputs pump light, the wavelength of the pump light corresponds to the resonance peak in the middle of FIG. 5, and the coupling between the waveguide and the resonant cavity system is regulated to be in a critical coupling state, so that the pump light is greatly enhanced in the second micro-ring resonant cavity; in the second micro-ring resonator, at the resonance peak satisfying the phase matching condition, as in the resonance peak at both sides of fig. 5, a signal light and idler photon pair is spontaneously generated, and it should be noted here that the FSR of the plurality of first micro-ring resonators may be spaced as long as the signal light wavelength and idler light wavelength are satisfied corresponding to the coupled resonance peak wavelength and symmetrical with respect to the pump light frequency.
The coupling coefficient of the waveguide and the first micro-ring resonant cavity is k 1 The transmission coefficient is r 1 The coupling coefficient between the first micro-ring resonant cavity and the second micro-ring resonant cavity is k 2 The transmission coefficient is r 2 . The first micro-ring resonant cavity has a ring pass coefficient of a 1 The second resonant cavity has a loop transmission coefficient of a 2 The loop transmission coefficient of the micro-ring resonator determines the magnitude of its own loss a=exp (- βl2), where β is the optical field transmission loss coefficient in the micro-ring resonator, including bending loss, scattering loss, and so on. The loop transmission coefficient a of the micro-ring resonant cavity is related to the cavity length of the micro-ring resonant cavity and the optical field transmission loss coefficient beta.
For a double micro-ring system, there areF p For the field enhancement factor +.>At the moment, the pump light is in a critical coupling state, has high gain, and the resonance peak of the signal light and the resonance peak of the idler frequency light are widened, so that a high equivalent coupling coefficient +.>A specific set of parameters as described aboveThe values are given in table 1 below;
TABLE 1
Under the condition that each resonance peak of the micro-ring resonant cavity can be independently regulated and controlled, the signal light resonance peak and the idler frequency light resonance peak can be widened, and the service life of photons emitted by the quantum light source is shortened.
According to the embodiment of the invention, the discrete regulation and control of the spectrum are realized by constructing the double-resonant-cavity single-waveguide coupling structure, and the signal light and idler frequency light resonance peaks are widened, so that quantum photon pair generation with adjustable photon service life is realized.
The input pump light generates resonance in the second micro-ring resonant cavity, and the resonance cannot be generated in the first micro-ring resonant cavity; the signal light and the idler light resonate within the first micro-ring resonator and the second micro-ring resonator. At this time, the coupling coefficients of the waveguide and the micro-ring resonant cavity are different at each resonant peak, so that the pump light has narrower resonant peak and small coupling coefficient, and the resonant peaks of the signal light and the idler frequency light are widened, thereby realizing the purposes of shortening and regulating the photon service life.
Fig. 7 is a flowchart of a single photon generation method for adjusting lifetime of photons, which is shown in fig. 7, and includes the following steps:
s101, coupling a waveguide with a first micro-ring resonant cavity, and coupling the first micro-ring resonant cavity with a second micro-ring resonant cavity; the radius of the first micro-ring resonant cavity is half of that of the second micro-ring resonant cavity, so that the resonant peak interval of the first micro-ring resonant cavity is twice of that of the second micro-ring resonant cavity, the resonant peak of the second micro-ring resonant cavity comprises an overlapped resonant peak and a non-overlapped resonant peak, the position of the resonant peak of the first micro-ring resonant cavity is overlapped with that of the overlapped resonant peak, and a non-overlapped resonant peak exists between every two overlapped resonant peaks;
S102, pump light is input to one side of a waveguide at a narrow resonance peak, signal light photons and idler light photons are spontaneously generated at a wide resonance peak, and the signal light photons and the idler light photons are coupled into the waveguide and output from the other side of the waveguide as a declarative single photon source; the intrinsic loss of the two micro-ring resonant cavities and the coupling coefficient of the waveguide and the first micro-ring resonant cavity are controlled to control the bandwidths of the wide resonant peak and the narrow resonant peak, so that the bandwidths of the output signal light photons and the idler frequency light photons are controlled, and the photon lives of the output signal light photons and the idler frequency light photons are controlled; the photon lifetime refers to the pulse width of a single photon in the time domain.
S103, pump light is input to one side of the waveguide at a narrow resonance peak, signal light photons and idler light photons are spontaneously generated at a wide resonance peak, and the signal light photons and the idler light photons are coupled into the waveguide and output from the other side of the waveguide as a declarative single photon source; controlling the intrinsic loss of the two micro-ring resonators and the coupling coefficient of the waveguide and the micro-ring resonators to control the bandwidths of the wide resonance peak and the narrow resonance peak; controlling the electrode of the first micro-ring resonant cavity to control the position of a first micro-ring resonant peak so as to regulate and control the bandwidths of the signal optical resonant peak and the idler optical resonant peak, thereby controlling the photon lives of the output signal optical photons and the idler optical photons; the photon lifetime refers to the pulse width of a single photon in the time domain.
Specifically, the detailed implementation of each step in fig. 7 may be referred to the description in the foregoing embodiment of the apparatus, which is not described herein.
It is to be understood that the terms such as "comprises" and "comprising," when used in this application, specify the presence of stated features, operations, or components, and are not to be limited to one or more additional features, operations, or components. In this application, terms such as "comprising" and/or "having" are to be construed to mean that a particular feature, number, operation, constituent element, component, or combination thereof is specified, but is not to be construed to exclude the presence or addition of one or more other features, numbers, operations, constituent elements, components, or combination thereof.
The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. A single photon source of adjustable photon lifetime comprising: the waveguide, the first micro-ring resonant cavity and the second micro-ring resonant cavity;
the waveguide is coupled with the first micro-ring resonant cavity, and the second micro-ring resonant cavity is coupled with the first micro-ring resonant cavity;
the radius of the first micro-ring resonant cavity is half of that of the second micro-ring resonant cavity, so that the resonant peak interval of the first micro-ring resonant cavity is twice of that of the second micro-ring resonant cavity; setting the resonance peak of the first micro-ring resonant cavity as a first resonance peak, and setting the resonance peak of the second micro-ring resonant cavity as a second resonance peak;
an electrode is arranged on the first micro-ring resonant cavity or the second micro-ring resonant cavity, after a first resonant peak and a second resonant peak are aligned by using an electric regulator through the electrode, an independent second resonant peak exists between every two pairs of aligned resonant peaks, the full width at half maximum of the aligned resonant peaks is larger than the full width at half maximum of the independent second resonant peaks, the aligned resonant peaks are respectively regarded as a wide resonant peak and a narrow resonant peak, then pumping light with the wavelength corresponding to the narrow resonant peak is input to one side of the waveguide, signal light photons and idler light photons are spontaneously generated at the wavelength corresponding to the wide resonant peak, and the signal light photons and the idler light photons are coupled into the waveguide and output from the other side of the waveguide as a single photon source;
The service life of the single photon source is adjustable, the adjusting mode comprises a coarse adjusting part and a fine adjusting part, and the coarse adjusting part comprises the following steps: aligning the first resonance peak and the second resonance peak by using the electrode to widen the aligned resonance peak, wherein the better the first resonance peak is aligned with the second resonance peak, the wider the bandwidth of the wide resonance peak is; fine adjustment is as follows: after obtaining a wide resonance peak, controlling the intrinsic loss of the two micro-ring resonant cavities and the coupling coefficient of the waveguide and the first micro-ring resonant cavity to finely adjust the bandwidth of the wide resonance peak, wherein the wider the bandwidth of the wide resonance peak is, the shorter the service lives of signal light photons and idler frequency light photons generated at the wavelength corresponding to the wide resonance peak are; the bandwidth of the wide resonance peak is comprehensively regulated and controlled by two modes of coarse regulation and fine regulation so as to control the service life of photons of the single photon source.
2. The single photon source as in claim 1 wherein the coupling coefficient of the first micro-ring resonator and the waveguide is set to be a first coupling coefficient, and the coupling coefficient of the second micro-ring resonator and the first micro-ring resonator is set to be a second coupling coefficient;
the first coupling coefficient and the second coupling coefficient are controlled to enable the resonant cavity system to be in critical coupling with the waveguide at the wavelength corresponding to the narrow resonance peak, and the generation efficiency of the signal light photons and the idler frequency light photons at the wavelength corresponding to the wide resonance peak is improved;
The first micro-ring resonant cavity and the second micro-ring resonant cavity form a resonant cavity system, the waveguide and the micro-ring resonant cavity system are in a critical coupling state at the wavelength corresponding to the narrow resonant peak, so that pump light input to the waveguide at the wavelength corresponding to the narrow resonant peak is completely coupled into the first micro-ring resonant cavity and the second micro-ring resonant cavity, and resonance is built in the second micro-ring resonant cavity;
the waveguide is in a critical coupling state with the micro-ring resonant cavity system at a wavelength corresponding to a narrow resonance peak, and specifically comprises the following steps: and adjusting the first coupling coefficient by adjusting the distance between the waveguide and the first micro-ring resonant cavity so that the coupling loss introduced by the waveguide is equal to the sum of the intrinsic loss of the first micro-ring resonant cavity and the intrinsic loss of the second micro-ring resonant cavity.
3. The single photon source of claim 2 wherein the fine tuning is: after the control waveguide is in a critical coupling state with the micro-ring resonant cavity system at a wavelength corresponding to the narrow resonance peak, when the first coupling coefficient or/and the intrinsic loss of the first micro-ring resonant cavity are increased, the bandwidth of the wide resonance peak is increased.
4. A single photon source of adjustable photon lifetime comprising: the first micro-ring resonant cavity, the second micro-ring resonant cavity and the waveguide;
The first micro-ring resonant cavity is coupled with the second micro-ring resonant cavity, the waveguide is coupled with the second micro-ring resonant cavity,
the radius of the first micro-ring resonant cavity is half of that of the second micro-ring resonant cavity, so that the resonant peak interval of the first micro-ring resonant cavity is twice of that of the second micro-ring resonant cavity; setting the resonance peak of the first micro-ring resonant cavity as a first resonance peak, and setting the resonance peak of the second micro-ring resonant cavity as a second resonance peak;
an electrode is arranged on the first micro-ring resonant cavity or the second micro-ring resonant cavity, after a first resonant peak and a second resonant peak are aligned by using an electric regulator through the electrode, an independent second resonant peak exists between every two pairs of aligned resonant peaks, the full width at half maximum of the aligned resonant peaks is larger than the full width at half maximum of the independent second resonant peaks, the aligned resonant peaks are respectively regarded as a wide resonant peak and a narrow resonant peak, then pumping light with the wavelength corresponding to the narrow resonant peak is input to one side of the waveguide, signal light photons and idler light photons are spontaneously generated at the wavelength corresponding to the wide resonant peak, and the signal light photons and the idler light photons are coupled into the waveguide and output from the other side of the waveguide as a single photon source;
the service life of the single photon source is adjustable, the adjusting mode comprises a coarse adjusting part and a fine adjusting part, and the coarse adjusting part comprises the following steps: aligning the first resonance peak and the second resonance peak by using the electrode to widen the aligned resonance peak, wherein the better the first resonance peak is aligned with the second resonance peak, the wider the bandwidth of the wide resonance peak is; fine adjustment is as follows: after obtaining a wide resonance peak, controlling the intrinsic loss of the two micro-ring resonant cavities and the coupling coefficient of the waveguide and the second micro-ring resonant cavity to finely adjust the bandwidth of the wide resonance peak, wherein the wider the bandwidth of the wide resonance peak is, the shorter the service lives of signal light photons and idler frequency light photons generated at the wavelength corresponding to the wide resonance peak are; the bandwidth of the wide resonance peak is comprehensively regulated and controlled by two modes of coarse regulation and fine regulation so as to control the service life of photons of the single photon source.
5. The single photon source as in claim 4 wherein the coupling coefficient of the second micro-ring resonator and the waveguide is set to be a first coupling coefficient, and the coupling coefficient of the second micro-ring resonator and the first micro-ring resonator is set to be a second coupling coefficient;
the first coupling coefficient and the second coupling coefficient are controlled to enable the resonant cavity system to be in critical coupling with the waveguide at the wavelength corresponding to the narrow resonance peak, and the generation efficiency of the signal light photons and the idler frequency light photons at the wavelength corresponding to the wide resonance peak is improved;
the first micro-ring resonant cavity and the second micro-ring resonant cavity form a resonant cavity system, the waveguide and the micro-ring resonant cavity system are in a critical coupling state at the wavelength corresponding to the narrow resonant peak, so that pump light input to the waveguide at the wavelength corresponding to the narrow resonant peak is completely coupled into the first micro-ring resonant cavity and the second micro-ring resonant cavity, and resonance is built in the second micro-ring resonant cavity;
the waveguide is in a critical coupling state with the micro-ring resonant cavity system at a wavelength corresponding to a narrow resonance peak, and specifically comprises the following steps: and adjusting the first coupling coefficient by adjusting the distance between the waveguide and the second micro-ring resonant cavity so that the coupling loss introduced by the waveguide is equal to the sum of the intrinsic loss of the first micro-ring resonant cavity and the intrinsic loss of the second micro-ring resonant cavity.
6. The single photon source as in claim 5 wherein said fine tuning is: after the control waveguide is in a critical coupling state with the micro-ring resonant cavity system at a wavelength corresponding to the narrow resonance peak, when the first coupling coefficient or/and the intrinsic loss of the first micro-ring resonant cavity are increased, the bandwidth of the wide resonance peak is increased.
7. A single photon source of adjustable photon lifetime comprising: the first waveguide, the first micro-ring resonant cavity, the second micro-ring resonant cavity and the second waveguide;
the first waveguide is coupled with the first micro-ring resonant cavity, the first micro-ring resonant cavity is coupled with the second micro-ring resonant cavity, and the second micro-ring resonant cavity is coupled with the second waveguide;
the radius of the first micro-ring resonant cavity is half of that of the second micro-ring resonant cavity, so that the resonant peak interval of the first micro-ring resonant cavity is twice of that of the second micro-ring resonant cavity; setting the resonance peak of the first micro-ring resonant cavity as a first resonance peak, and setting the resonance peak of the second micro-ring resonant cavity as a second resonance peak;
an electrode is arranged on the first micro-ring resonant cavity or the second micro-ring resonant cavity, after a first resonant peak and a second resonant peak are aligned by using an electric tone through the electrode, an independent second resonant peak exists between every two pairs of aligned resonant peaks, the full width at half maximum of the aligned resonant peaks is larger than the full width at half maximum of the independent second resonant peaks, the aligned resonant peaks are respectively regarded as a wide resonant peak and a narrow resonant peak, then pumping light with the wavelength corresponding to the narrow resonant peak is input to one side of a preset waveguide, signal light photons and idler light photons are spontaneously generated at the wavelength corresponding to the wide resonant peak, and the signal light photons and the idler light photons are coupled into the waveguide and output from the other side of the preset waveguide as a single photon source; the preset waveguide is a first waveguide or a second waveguide;
The service life of the single photon source is adjustable, the adjusting mode comprises a coarse adjusting part and a fine adjusting part, and the coarse adjusting part comprises the following steps: aligning the first resonance peak and the second resonance peak by using the electrode to widen the aligned resonance peak, wherein the better the first resonance peak is aligned with the second resonance peak, the wider the bandwidth of the wide resonance peak is; fine adjustment is as follows: after obtaining a wide resonance peak, controlling the intrinsic loss of the two micro-ring resonant cavities and the coupling coefficient of the preset waveguide and the micro-ring resonant cavities to finely adjust the bandwidth of the wide resonance peak, wherein the wider the bandwidth of the wide resonance peak is, the shorter the service lives of signal light photons and idler frequency light photons are generated at the wavelength corresponding to the wide resonance peak; the bandwidth of the wide resonance peak is comprehensively regulated and controlled by two modes of coarse regulation and fine regulation so as to control the service life of photons of the single photon source.
8. The single photon source as in claim 7 wherein the first coupling coefficient of the first micro-ring resonator and the first waveguide is a first coupling coefficient, the second coupling coefficient of the second micro-ring resonator and the first micro-ring resonator is a second coupling coefficient, and the second coupling coefficient of the second micro-ring resonator and the second waveguide is a third coupling coefficient;
when pump light is input from the first waveguide, the first coupling coefficient and the second coupling coefficient are controlled to enable the resonant cavity system to be in critical coupling with the first waveguide at the wavelength corresponding to the narrow resonance peak, and the generation efficiency of signal light photons and idler frequency light photons at the wavelength corresponding to the wide resonance peak is improved; the first micro-ring resonant cavity and the second micro-ring resonant cavity form a resonant cavity system, the first waveguide and the micro-ring resonant cavity system are in a critical coupling state at the wavelength corresponding to the narrow resonant peak, so that pump light input to the first waveguide at the wavelength corresponding to the narrow resonant peak is completely coupled into the first micro-ring resonant cavity and the second micro-ring resonant cavity, and resonance is built in the second micro-ring resonant cavity;
The first waveguide is in a critical coupling state with the micro-ring resonant cavity system at a wavelength corresponding to a narrow resonance peak, specifically: and adjusting the first coupling coefficient by adjusting the distance between the first waveguide and the first micro-ring resonant cavity, so that the coupling loss introduced by the first waveguide is equal to the sum of the intrinsic loss of the first micro-ring resonant cavity, the intrinsic loss of the second micro-ring resonant cavity and the coupling loss introduced by the second waveguide.
9. The single photon source as in claim 8 wherein when pump light is input from the second waveguide, the first coupling coefficient and the second coupling coefficient are controlled to enable the resonant cavity system to be critically coupled with the second waveguide at a wavelength corresponding to a narrow resonance peak, thereby improving the generation efficiency of signal light photons and idler light photons at a wavelength corresponding to a wide resonance peak; the first micro-ring resonant cavity and the second micro-ring resonant cavity form a resonant cavity system, the second waveguide is in a critical coupling state with the micro-ring resonant cavity system at the wavelength corresponding to the narrow resonant peak, so that pump light input to the second waveguide at the wavelength corresponding to the narrow resonant peak is completely coupled into the first micro-ring resonant cavity and the second micro-ring resonant cavity, and resonance is built in the second micro-ring resonant cavity;
The second waveguide is in a critical coupling state with the micro-ring resonant cavity system at a wavelength corresponding to the narrow resonance peak, specifically: and adjusting a third coupling coefficient by adjusting the distance between the second waveguide and the second micro-ring resonant cavity, so that the coupling loss introduced by the second waveguide is equal to the sum of the intrinsic loss of the first micro-ring resonant cavity, the intrinsic loss of the second micro-ring resonant cavity and the coupling loss introduced by the first waveguide.
10. The single photon source as in any one of claims 7 to 9 wherein the fine tuning is: after the preset waveguide is controlled to be in a critical coupling state with the micro-ring resonant cavity system at the wavelength corresponding to the narrow resonance peak, when the third coupling coefficient or/and the intrinsic loss of the first micro-ring resonant cavity or/and the first coupling coefficient are increased, the bandwidth of the wide resonance peak is increased.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10372014B1 (en) * 2018-11-15 2019-08-06 Psiquantum, Corp. Coupled resonator photon-pair sources
CN114137664A (en) * 2020-09-03 2022-03-04 华中科技大学 Double-resonant-cavity double-waveguide coupling structure for improving all-optical wavelength conversion efficiency
CN114280730A (en) * 2021-06-29 2022-04-05 华中科技大学 Double-resonant-cavity double-waveguide filtering system and method
CN114675465A (en) * 2022-03-29 2022-06-28 华中科技大学 System and method for generating spectral de-entangled photon pairs
CN114675466A (en) * 2022-03-29 2022-06-28 华中科技大学 Quantum light source system and method for improving brightness of quantum light source
CN115268162A (en) * 2021-04-30 2022-11-01 华中科技大学 Nonlinear optical device
CN115268161A (en) * 2021-04-30 2022-11-01 华中科技大学 System and method for realizing phase regeneration with low power consumption
CN115561944A (en) * 2022-09-06 2023-01-03 华中科技大学 Declared single photon source generation device and method

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10372014B1 (en) * 2018-11-15 2019-08-06 Psiquantum, Corp. Coupled resonator photon-pair sources
CN114137664A (en) * 2020-09-03 2022-03-04 华中科技大学 Double-resonant-cavity double-waveguide coupling structure for improving all-optical wavelength conversion efficiency
CN115268162A (en) * 2021-04-30 2022-11-01 华中科技大学 Nonlinear optical device
CN115268161A (en) * 2021-04-30 2022-11-01 华中科技大学 System and method for realizing phase regeneration with low power consumption
CN114280730A (en) * 2021-06-29 2022-04-05 华中科技大学 Double-resonant-cavity double-waveguide filtering system and method
CN114675465A (en) * 2022-03-29 2022-06-28 华中科技大学 System and method for generating spectral de-entangled photon pairs
CN114675466A (en) * 2022-03-29 2022-06-28 华中科技大学 Quantum light source system and method for improving brightness of quantum light source
CN115561944A (en) * 2022-09-06 2023-01-03 华中科技大学 Declared single photon source generation device and method

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Bowen Zhang等.Bandwidth Tunable Optical Bandpass Filter Based on Parity-Time Symmetry.《micromachines》.2022,第13卷(第89期),全文. *

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