A narrow linewidth pulse laser for Rydberg atom excitation

Abstract

The invention discloses a pulse laser system for realizing a single photon source by Rydberg atom excitation, which comprises at least one seed source laser unit, a continuous laser monitoring unit, a pulse laser generating unit, a pulse laser monitoring unit, a laser power amplifying unit, and a laser wavelength conversion unit. The seed source laser unit is connected to the pulse generating unit by optical fiber, the pulse laser generating unit is connected to the laser power amplifying unit by optical fiber, the laser power amplifying unit is connected to the laser wavelength conversion unit by optical fiber, the seed source laser unit, the pulse laser generating unit and the laser monitoring unit are connected to optical fiber and output by optical fiber. The invention belongs to the field of laser technology, and specifically refers to a pulse laser that generates narrow line width pulse light for realizing a single photon source by Rydberg atom excitation.

Description

Technical Field

[0001] The invention relates to the technical field of lasers, in particular to a narrow line width pulse laser for Rydberg atom excitation. Background Art

[0002] As a quantum resource, single photons have important application value in quantum computing and quantum secure communication. High-purity single photon sources can carry out linear quantum computing; as flying bits of quantum information transmission, single photons have weak interactions with the environment and are suitable for long-distance quantum information transmission; single photons that match atomic transition lines are suitable for quantum state manipulation and as a medium for quantum computing and quantum storage, playing an important role in quantum networks and quantum interfaces.

[0003] With the deepening of single-photon source research, high-efficiency and high-fidelity single-photon sources have been realized based on physical carriers such as single atoms, single molecules, single ions, single quantum dots, and single NV centers. Single-photon source systems based on the above systems usually require ultra-low temperatures or extreme environments to operate, which limits the practical development of the system. The Rydberg atomic ensemble with strong interactions can achieve single-particle excitation through the excitation blockade effect, which provides a scalable miniaturized single-photon source solution with practical value.

[0004] The atomic system in the micrometer gas chamber has a coherence time of nanoseconds due to strong spatial localization and the interaction between atoms and the material surface. This makes it possible to realize a single photon source with a GHz bandwidth, but also poses a challenge to the nanosecond scale coherent manipulation of atomic systems. 133 The Rydberg state excitation of Cs atoms requires 852 nm and 510 nm laser systems. The 852 nm laser can chop continuous light into nanosecond pulse light through an electro-optical intensity modulator (EOIM); the maximum input optical power of the chopped pulse light scheme based on EOIM is less than 100 mW, and the chopping power loss is greater than 60 dB. For 510 nm lasers, due to device material and process limitations, there are currently no ns-scale EOIM devices. The strong interaction of Rydberg atoms is used to realize a single-photon source in a room-temperature ensemble atom. The regulation of atomic states at the ns scale is the core content, and a high-power ns pulse laser system is a key device. At present, there are no laser systems with relevant parameters for sale at home and abroad. Therefore, the present invention designs a high-power narrow-linewidth pulse laser for Rydberg atom excitation. This design can be extended to Rydberg excitation applications in various atomic systems such as rubidium and cesium. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a narrow line width pulse laser for Rydberg atom excitation.

[0006] To solve the above technical problems, the present invention is implemented through the following technical solutions: a narrow linewidth pulse laser for Rydberg atom excitation is provided, comprising at least one seed source laser unit, a continuous laser monitoring unit, a pulse laser generating unit, a pulse laser monitoring unit, a laser power amplification unit, and a laser wavelength conversion unit, wherein the seed source laser unit is optically connected to the pulse laser generating unit, the pulse laser generating unit is optically connected to the laser power amplification unit, the laser power amplification unit is optically connected to the laser wavelength conversion unit, the seed source laser unit is optically connected to the continuous laser monitoring unit and outputs optical fiber, and the pulse laser generating unit is optically connected to the pulse laser monitoring unit and outputs optical fiber.

[0007] A further technical solution is: the seed source laser unit is a wavelength-adjustable narrow-linewidth continuous output light source.

[0008] Its further technical solution is: the continuous laser monitoring unit is an optical fiber integrated 10 / 90 laser power beam splitter connected to the output end of the seed source laser unit, and the beam splitter inputs the output laser to an oscilloscope to monitor the laser output by the seed source laser unit.

[0009] A further technical solution is as follows: the pulse laser generating unit is a Mach-Zehnder type electro-optic intensity modulator (EOIM), the material used is LiNbO3 crystal, and the bandwidth is 20 GHz.

[0010] Its further technical solution is: the pulse laser monitoring unit is an optical fiber integrated 10 / 90 laser power beam splitter connected to the output end of the pulse laser generating unit, and the beam splitter inputs the output laser to an oscilloscope to monitor the laser output by the pulse laser generating unit.

[0011] A further technical solution is: the laser power amplification unit is a pulse fiber amplifier.

[0012] A further technical solution is: the laser wavelength conversion unit is a fiber-integrated PPLN frequency-doubling crystal.

[0013] Compared with the prior art, the present invention has the following beneficial effects: the present invention modulates the intensity of a wavelength-adjustable narrow linewidth continuous seed source. Specifically, the bias voltage of the MZ electro-optic intensity modulator (EOIM) port is adjusted to change the refractive index of the light wave during the transmission of the two arms, and then the phase changes, which is then converted into intensity changes after beam combining interference, thereby generating ns-scale pulsed lasers. After that, the pulsed fiber amplifier is cascaded to output a pulsed laser with a power of 5000 kW, an adjustable repetition frequency of 0.1~100MHz, and an adjustable pulse width of 1~100 ns. Finally, the wavelength of the generated pulsed laser is converted using a PPLN frequency-doubling crystal to obtain a high-power ns-scale narrow linewidth pulsed laser.

[0014] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0016] Figure 1 A schematic block diagram of a narrow linewidth pulse laser for Rydberg atom excitation provided by an embodiment of the present invention.

[0017] Figure 2 A pulse waveform diagram of a 1018 nm laser output from the output end of a pulse laser fiber provided in an embodiment of the present invention.

[0018] Figure 3 This is a relationship diagram between the 1018nm laser power output from the output end of the pulsed laser fiber and the pump laser power provided in an embodiment of the present invention.

[0019] Figure 4 The pulse laser provided in the embodiment of the present invention generates a 509 nm frequency-doubled laser pulse waveform.

[0020] Figure 5 A relationship diagram between the 509 nm frequency-doubled laser power and the 1018 nm laser power of the pulsed laser provided in an embodiment of the present invention.

[0021] Figure 1 Component markings: 1-seed source, 2-continuous laser monitoring unit (Minitor), 3-electro-optical intensity modulator (EOIM), 4-pulse laser monitoring unit (Minitor), 5-pulse fiber amplifier, 6-PPLN frequency doubling crystal, 7-fiber output (Output) end. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] like Figure 1 The invention discloses a narrow linewidth pulse laser for Rydberg atom excitation, which comprises a seed source 1; a continuous laser monitoring unit (Minitor) 2; an electro-optical intensity modulator (EOIM) 3; a pulse laser monitoring unit (Minitor) 4; a pulse fiber amplifier 5; a PPLN frequency doubling crystal 6; and an optical fiber output (Output) end 7. The seed source 1 is intensity modulated by the electro-optical intensity modulator (EOIM) 3, the electro-optical intensity modulator (EOIM) 3 is connected to the pulse fiber amplifier 5, the pulse fiber amplifier 5 is connected to the PPLN frequency doubling crystal 6, and the PPLN frequency doubling crystal 6 is connected to the optical fiber output (Output) end 7.

[0024] The seed source 1 outputs a continuous laser with a central wavelength of 1017.5064 nm and a tuning range of 0.6 nm and a narrow line width.

[0025] The continuous laser monitoring unit (Minitor) 2 monitors the seed source 1 to output an adjustable narrow line width continuous laser.

[0026] The pulse laser monitoring unit (Minitor) 4 monitors the pulse laser obtained by the electro-optic intensity modulator (EOIM) 3 .

[0027] The optical fiber output (Output) end 7 outputs the pulsed laser after the wavelength is converted by the PPLN frequency doubling crystal.

[0028] The pulse laser uses an electro-optic intensity modulator (EOIM) 3 to modulate the phase-locked 1018 nm narrow-linewidth continuous laser output by the seed source 1 to generate a ns-scale continuously adjustable pulse laser. After cascade amplification by a pulse fiber amplifier 5, a pulse laser with kW power, MHz repetition frequency, and ns pulse width is output. The central wavelength is 1017.8 nm, the tuning range is 0.9 nm, the output power is 5000 KW, the repetition frequency is adjustable from 0.1 to 100 MHz, the pulse width is adjustable from 1 to 100 ns, and the pulse delay is continuously adjustable. The output continuously adjustable pulse laser is converted into a laser wavelength using a PPLN frequency doubling crystal to obtain a high-power, ns-scale 509 nm single-frequency pulse laser.

[0029] Figure 2 The pulse waveform diagram of 1018 nm laser output from the output end of the pulse laser fiber provided in the embodiment of the present invention. Figure 2 , The waveform of the 1018 nm laser pulse is obtained when the 1018 nm laser power is 12 W, the repetition frequency of the input pulse signal is 1 MHz, the amplitude is 300 mV, and the pulse width is 5 ns.

[0030] Figure 3 The relationship between the 1018 nm laser power output from the output end of the pulsed laser fiber and the pump laser power provided by the embodiment of the present invention. Figure 3 The relationship between the 1018 nm laser power output from the fiber output (Output) end of the pulsed laser and the pump laser power was measured when the repetition frequency of the input pulse signal was 100 MHz, the amplitude was 300 mV, and the pulse width was 5 ns. The 1018 nm laser power output from the fiber output (Output) end increased with the pump laser power.

[0031] Figure 4 The pulse laser provided in the embodiment of the present invention generates a 509 nm frequency-doubled laser pulse waveform. Figure 4 , when the 1018 nm laser power is 12 W, the repetition frequency of the input pulse signal is 1 MHz, the amplitude is 300 mV, and the pulse width is 5 ns, the waveform of the 509 nm frequency-doubled laser pulse is obtained.

[0032] Figure 5 The relationship between the 509 nm frequency-doubled laser power and the 1018 nm laser power of the pulsed laser provided in the embodiment of the present invention is shown in FIG. Figure 5 The relationship between the 509 nm laser power output by the laser wavelength conversion unit in the pulse laser and the 1018 nm laser power was measured when the input pulse signal repetition frequency was 1 MHz and the pulse width was 5 ns. The 509 nm laser power increased with the 1018 nm laser power and tended to saturation at a certain power. When the 1018 nm laser power reached 15 W, the 509 nm laser power tended to saturation.

[0033] It is expected that the present invention will be used to realize the pulsed laser of a single photon source. The prior art uses an electro-optical intensity modulator to chop continuous light into nanosecond pulsed light, but the pulsed light produced has the disadvantages of low power and poor beam quality, resulting in poor stability of the single photon source produced by the pulsed light. Therefore, a pulsed laser with KW output power, MHz repetition frequency, and ns-scale pulse width is prepared by using the above-mentioned narrow linewidth pulse laser for Rydberg atom excitation, wherein the central wavelength is 1017.8nm, the tuning range is 0.9 nm, the output power is 5000 KW, the repetition frequency is adjustable from 0.1 to 100 MHz, the pulse width is adjustable from 1 to 100 ns, and the pulse delay is continuously adjustable. Afterwards, the laser wavelength is converted by a PPLN frequency doubling crystal to obtain a high-power, ns-scale 509 nm single-frequency pulsed laser. Thus, a pulsed laser for a single photon source is realized.

[0034] The present invention and its embodiments are described above, and such description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design a structure and embodiment similar to the technical solution without creativity, which should belong to the protection scope of the present invention.

Claims

1. A narrow linewidth pulse laser for Rydberg atom excitation, characterized in that: The invention comprises at least one seed source laser unit, a continuous laser monitoring unit, a pulse laser generating unit, a pulse laser monitoring unit, a laser power amplifying unit and a laser wavelength conversion unit. The seed source laser unit is connected to the pulse laser generating unit by optical fiber, the pulse laser generating unit is connected to the laser power amplifying unit by optical fiber, the laser power amplifying unit is connected to the laser wavelength conversion unit by optical fiber, the seed source laser unit is connected to the continuous laser monitoring unit by optical fiber and outputs optical fiber, the pulse laser generating unit is connected to the pulse laser monitoring unit by optical fiber and outputs optical fiber; the pulse laser generating unit is an electro-optical intensity modulator; the laser wavelength conversion unit is an optical fiber integrated PPLN frequency doubling crystal.

2. A narrow linewidth pulse laser for Rydberg atom excitation according to claim 1, characterized in that: The seed source laser unit is a wavelength-adjustable narrow-linewidth continuous laser output fiber laser.

3. A narrow linewidth pulse laser for Rydberg atom excitation according to claim 1, characterized in that: The continuous laser monitoring unit is an optical fiber integrated 10 / 90 laser power beam splitter connected to the output end of the seed source laser unit.

4. A narrow linewidth pulse laser for Rydberg atom excitation according to claim 1, characterized in that: The pulse laser monitoring unit is an optical fiber integrated 10 / 90 laser power beam splitter connected to the output end of the pulse laser generating unit.

5. A narrow linewidth pulse laser for Rydberg atom excitation according to claim 1, characterized in that: The laser power amplification unit is a pulse fiber amplifier.

6. A narrow linewidth pulse laser for Rydberg atom excitation according to claim 1, characterized in that: The intensity of the wavelength-adjustable narrow-linewidth continuous laser output by the fiber laser is modulated by an electro-optic intensity modulator to generate ns-scale pulsed laser, which is then cascade-amplified by a pulse fiber amplifier to output a pulsed laser with a power of 5000 kW, an adjustable repetition frequency of 0.1~100 MHz, and an adjustable pulse width of 1~100 ns. The wavelength of the generated pulsed laser is then converted using a PPLN frequency-doubling crystal to obtain a high-power ns-scale narrow-linewidth pulsed laser.

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