Telecommunication network

Abstract

The present invention provides a method for operating a central node in a telecommunications network, the telecommunications network comprising an optical network and a plurality of distributed nodes, each distributed node being configured to use a first optical signal of a first wavelength, the method comprising the steps of: generating a first optical signal of a second wavelength; directing the first optical signal into a first path for the first optical signal and a second path for the first optical signal, wherein the first path for the first optical signal is connected to a first optical stabilizer to stabilize the first optical signal generated by the central node, and the second path for the first optical signal provides the first optical signal to the optical network for distribution to each of the plurality of distributed nodes, wherein the second wavelength has a lower transmission loss than the first wavelength.

Description

Technical Field

[0001] The present invention relates to a telecommunication network including an optical network. Background Art

[0002] Many technologies require a stable laser signal, such as emerging Rydberg atom-based technologies including atomic radio detectors, atomic clocks, and atomic gravimeters. These Rydberg atom-based technologies typically use a laser signal to excite electrons in an atomic medium (usually including rubidium, cesium, or strontium atoms) to the Rydberg state. For example, in an atomic radio detector with an atomic medium based on rubidium-85 atoms, a first laser signal at 780 nm can be used to excite electrons from the ground state of rubidium atoms to the first excited state, and then a second laser signal can be used to excite the electrons from this first excited state to the Rydberg state. For long-term operation, these laser signals should be stable at these wavelengths. In one example, the stability of the laser signal required to transition electrons from the ground state of rubidium-85 atoms to the first excited state (which has a linewidth of about 6 MHz) should be less than 1 MHz within the time range of operation (i.e., its deviation should not exceed 1 MHz) to ensure effective operation. This can be achieved using saturated absorption spectroscopy techniques, but this requires expensive and dedicated equipment. Therefore, the large-scale deployment of devices incorporating Rydberg atom-based technologies (such as in a wireless telecommunication network where each wireless device includes a Rydberg atom-based radio frequency detector) may be prohibitively expensive because each device requires local application of saturated absorption spectroscopy to stabilize the laser signal. Summary of the Invention

[0003] According to a first aspect of the present invention, there is provided a method of operating a central node in a telecommunication network, the telecommunication network including an optical network and a plurality of distributed nodes, each distributed node being configured to use a first optical signal at a first wavelength, the method comprising the steps of: generating a first optical signal at a second wavelength; directing the first optical signal into a first path for the first optical signal and a second path for the first optical signal, wherein the first path for the first optical signal is connected to a first optical stabilizer to stabilize the first optical signal generated by the central node, and the second path for the first optical signal provides the first optical signal to the optical network for distribution to each of the plurality of distributed nodes, wherein the second wavelength has a lower transmission loss than the first wavelength.

[0004] The first path for the first optical signal may include a first wavelength converter for converting the first optical signal from the second wavelength to the first wavelength before stabilization by the optical stabilizer.

[0005] The second wavelength can be in the range from 1260 nm to 1625 nm.

[0006] Each of the plurality of distributed nodes can be configured to use a second optical signal of a third wavelength, and the method may further include the steps of: generating a second optical signal of a fourth wavelength; guiding the second optical signal into a first path for the second optical signal and a second path for the second optical signal, wherein the first path for the second optical signal is connected to a second optical stabilizer to stabilize the second optical signal generated by the central node, and the second path for the second optical signal provides the second optical signal to the optical network for distribution to each of the plurality of distributed nodes, wherein the fourth wavelength has a lower transmission loss than the third wavelength.

[0007] The first path for the second optical signal may include a second wavelength converter for converting the second optical signal from the fourth wavelength to the third wavelength before stabilization by the second optical stabilizer.

[0008] The fourth wavelength can be in the range from 1260 nm to 1625 nm.

[0009] After the first wavelength converter converts the first optical signal, the second wavelength converter can convert the second optical signal from the fourth wavelength to the third wavelength by mixing the second optical signal of the fourth wavelength with the first optical signal of the first wavelength.

[0010] Each of the plurality of distributed nodes can use the first optical signal of the first wavelength to excite the electron of the Rydberg atom from the first state to the second state.

[0011] Each of the plurality of distributed nodes can use the second optical signal of the third wavelength to excite the electron of the Rydberg atom from the second state to the third state.

[0012] The Rydberg atom can be part of a Rydberg-atom-based radio frequency (RF) receiver.

[0013] The optical network can distribute the first optical signal on a hollow-core optical fiber.

[0014] The optical network can distribute the second optical signal on a hollow-core optical fiber.

[0015] According to a second aspect of the present invention, there is provided a computer program comprising instructions which, when executed by a computer, cause the computer to perform the steps of the first aspect of the present invention. The computer program can be stored on a computer-readable carrier medium.

[0016] According to a third aspect of the present invention, there is provided a node for a telecommunications network, the telecommunications network comprising an optical network and a plurality of distributed nodes, each distributed node being configured to use a first optical signal of a first wavelength, the node comprising: a first light source configured to generate a first optical signal of a second wavelength, wherein the second wavelength has a lower transmission loss than the first wavelength; a first optical stabilizer configured to stabilize the first optical signal; a communication interface connectable to the optical network; and a first splitting unit configured to direct the first optical signal into a first path for the first optical signal and a second path for the first optical signal, wherein the first path for the first optical signal is connected to the first optical stabilizer and the second path for the first optical signal is connected to the communication interface so as to provide the first optical signal to the optical network for distribution to each of the plurality of distributed nodes. The node may be part of a telecommunications network which also includes an optical network and a plurality of distributed nodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] For a better understanding of the present invention, embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0018] Figure 1 is a schematic diagram of a cellular telecommunications network according to a first embodiment of the present invention;

[0019] Figure 2 is Figure 1 a schematic diagram of a Rydberg atom-based radio frequency receiver of a base station of the network of

[0020] Figure 3 is a flow chart of a first embodiment of the method of the present invention, showing a first process implemented by a core networking node of the network of Figure 1 ;

[0021] Figure 4 is a flow chart of a first embodiment of the method of the present invention, showing a second process implemented by each base station of the network of Figure 1 ;

[0022] Figure 5 is a schematic diagram of a cellular telecommunications network according to a second embodiment of the present invention; and

[0023] Figure 6 is a schematic diagram of a cellular telecommunications network according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0024] Reference will now be made to Figure 1Describe a first embodiment of a telecommunications network. This embodiment is based on a cellular telecommunications network including a core network node 10 and a plurality of base stations 20, 30, 40, 50. The core network node 10 is connected to each of the plurality of base stations via an optical distribution network 60.

[0025] As Figure 1 shown, the core network node 10 includes a master laser 12 configured to generate a laser signal at 1560 nm. The core network 10 also includes a splitter 14, a wavelength converter 16, and a laser stabilizer 18. In this embodiment, the wavelength converter 16 is based on second harmonic generation (SHG) periodic poling of nonlinear (PPLN) optical waveguides to halve the wavelength of the 1560 nm laser signal from the master laser 12 to 780 nm. An example of this technique is described in European Patent No. 0331303 B1. Additionally, in this embodiment, the laser stabilizer 18 is based on modulation transfer spectroscopy (MTS), and the laser stabilizer 18 stabilizes the 780 nm laser signal after conversion by the wavelength converter to the desired level of stability. Examples of this technique are described in U.S. Patent No. 4590597.

[0026] Figure 1 Also shown is that each of the plurality of base stations 20, 30, 40, 50 includes an amplifier 22, 32, 42, 52, wavelength converters 24, 34, 36, 46, and a Rydberg atom-based radio frequency (RF) receiver 26, 36, 46, 56. The Rydberg atom-based RF receiver 26 of the first base station 20 among the plurality of base stations 20, 30, 40, 50 is Figure 2 shown and operates as follows (and those skilled in the art will recognize that the Rydberg atom-based RF receivers of the other base stations among the plurality of base stations can operate in the same manner). An atomic medium 26a is provided, which in this example is a glass cell filled with a low-density vapor of an alkaline atom such as rubidium-85. Each rubidium-85 atom has a number of electronic states, including a ground state (|1>) and a plurality of excited states. The outer electron of the rubidium-85 atom can be excited from the ground state (|1>) (e.g., by absorbing photons of a specific wavelength) to an excited state. Then, the electron can decay from the excited state to a lower excited state (i.e., an excited state of a lower energy level) or decay to the ground state (|1>). However, some of these transitions are not allowed because they are dipole forbidden.

[0027] In an RF receiver, a laser signal (initially received from core network node 10) is passed through an atomic medium 26a, and the outer electrons of rubidium-85 atoms are lifted from their ground state (|1>) to the first excited state (|2>). This lifting occurs due to the 780 nm wavelength of the laser signal, which corresponds to the energy required to lift the outer electrons of rubidium-85 atoms from the ground state (|1>) to the first excited state (|2>). In this article, the laser signal may be referred to as a "probe" signal. A second "coupling" laser signal (generated by coupling laser 26b) is also passed through the atomic medium 26a in the opposite direction at a relatively large power level (compared to the probe laser) and at a second wavelength corresponding to the energy required to lift the outer electrons of rubidium-85 atoms from the first excited state (|2>) to the Rydberg state (|3>). The transition from the Rydberg state (|3>) to the ground state (|1>) is forbidden, making the ground state (|1>) less populated, and thus fewer atoms can absorb the 780 nm laser signal. As a result, the atomic medium 26a becomes more transparent to the 780 nm laser signal, increasing the transmission of the 780 nm laser signal through the atomic medium 26a, which can be observed at the optical detector 26c. This phenomenon is called electromagnetically induced transparency (EIT), and the received signal is called an EIT signal. Specifically, the above-described is the ladder scheme EIT effect, but those skilled in the art will understand that the EIT effect can be achieved through alternative electronic transitions, such as the Vee and Lambda schemes.

[0028] Once the atomic medium 26a becomes transparent to 780 nm, a further physical effect can be utilized to detect the RF electric field. Since the outer electrons of rubidium-85 atoms are much farther from the atomic nucleus when in the Rydberg state compared to the ground state, a large dipole moment is created, and it becomes responsive to the incident RF electric field. The incident RF electric field can cause further transitions of the electrons from the Rydberg state to another Rydberg state. If the transition from the other Rydberg state to the ground state is not forbidden, the electrons may then drop to the ground state, making the atomic medium 26a less transparent to the 780 nm laser signal, resulting in a decrease in the amplitude of the EIT signal. This decrease in the amplitude of the EIT signal is proportional to the amplitude of the incident RF electric field, thus creating a Rydberg-atom-based AM RF receiver. In the article "A Multiple-Band Rydberg-Atom Based Receiver / Antenna: AM / FM Stereo Reception", Holloway et al., National Institute of Standards and Technology).

[0029] In addition, Rydberg-atom-based FM RF receivers work in a similar manner. That is, when the RF electric field changes (or "detunes") from its resonant RF transition frequency, the EIT signal splits into two asymmetric peaks. The separation of the two peaks increases with RF detuning. By locking the 780 nm laser signal and coupling the laser to a specific frequency, the photodetector output is directly related to the FM RF electric field. In the article "A Multiple-Band Rydberg-Atom Based Receiver / Antenna: AM / FM Stereo Reception", Holloway et al., National Institute of Standards and Technology) and the article "Using frequency detuning to improve the sensitivity of electric field measurements via electromagnetic induced transparency and Autler-Townes splitting in Rydberg atoms", Appl. Phys. Lett. 108, 174101 (2016), Matt T. Simons.

[0030] Rydberg RF receivers can also be used to detect phase-modulated RF fields, such as those of binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), and quadrature amplitude modulation (QAM) signals (used in many wireless and cellular communication protocols). In these modulation schemes, data is sent by modulating the phase of a carrier wave. To detect the phase of the carrier wave, a reference RF field with a resonance for a transition to the Rydberg state is applied to the atomic medium acting as a local oscillator. The difference frequency or "intermediate frequency" is detected, and the phase of the intermediate frequency signal directly corresponds to the relative phase between the local oscillator and the incident RF electric field.

[0031] Regardless of the modulation scheme (amplitude, frequency, or phase) used, a Rydberg-atom-based RF detector can be configured to detect an RF field at a specific frequency by selecting a specific second wavelength of the coupling laser 26b such that electrons in the atomic medium 26a are promoted to a specific Rydberg state. This Rydberg state is selected such that photons at the specific frequency to be detected promote the electrons from this Rydberg state to its adjacent Rydberg state, thereby creating a detectable change in the EIT signal observable at the photodetector 26c.

[0032] Reference will now be made to Figure 1 the cellular telecommunications network andFigure 3 and Figure 4 The first embodiment of the method of the present invention is described by the flow chart of Figure 3 . In the first step S101, as shown in Figure 3 , the master laser 12 generates a laser signal of 1560 nm. In step S103, the laser signal is transmitted to the splitter 14, and the splitter 14 splits the laser signal into a local path and a plurality of distribution paths. The local path guides the 1560 nm laser signal to the wavelength converter 16 of the core network node, and each distribution path guides the 1560 nm laser signal to a specific base station among the plurality of base stations 20, 30, 40, 50. Along the local path, in step S105, the wavelength converter 16 converts the 1560 nm laser signal into a 780 nm laser signal, and then guides it to the laser stabilizer 18. In step S107, the laser stabilizer 18 generates an error signal. In step S109, the error signal is fed back to the master laser 12 to stabilize its laser signal in step S109.

[0033] Along the distribution path, the 1560 nm laser signal is distributed to each of the plurality of base stations 20, 30, 40, 50 through a specific distribution path in the optical network 60. In step S201, as shown in Figure 4 , each of the plurality of base stations 20, 30, 40, 50 receives the 1560 nm laser signal from the core network node 10 at the amplifiers 22, 32, 42, 52, and the amplifiers 22, 32, 42, 52 amplify the 1560 nm signal to compensate for any power reduction of the wavelength converters 24, 34, 44, 54. In step S203, the amplified 1560 nm laser signal is guided to the wavelength converters 24, 34, 44, 54, and the wavelength converters 24, 34, 44, 54 convert the 1560 nm laser signal into a 780 nm laser signal. In step S205, the 780 nm laser signal is guided to the Rydberg-atom-based RF receivers 26, 36, 46, 56 and is used to excite the electrons of the atomic medium of rubidium-85 atoms from the ground state to the first excited state (as described above).

[0034] The above embodiment can distribute a stable laser signal from a single node to multiple devices, and each device uses a Rydberg-atom-based RF receiver. In the prior art, each device using a Rydberg-atom-based RF receiver would require its own stabilizer. However, by distributing the laser signal and implementing a stabilizer in the core network node before distribution, the number of stabilizers required in the network is reduced from N (where N is the count of devices using Rydberg-atom-based RF receivers) to 1.

[0035] ​​​​In addition, when the wavelength converters of each base station 20, 30, 40, 50 apply the same conversion to the wavelength converter 16 of the core network node (i.e., output laser signals of the same wavelength), the laser signals used in the laser stabilizer 18 of the core network node and the Rydberg-atom-based RF receivers 26, 36, 46, 56 of the multiple base stations 20, 30, 40, 50 have the same wavelength. This ensures that the error signal generated by the laser stabilizer 18 stabilizes the master laser 12 to the precision required for the operation of the Rydberg-atom-based RF receivers in each of the multiple base stations 20, 30, 40, 50. However, this is not necessary because the stabilization unit can be based on an alternative technology that does not require wavelength conversion, such as a frequency comb or a stable cavity.

[0036] The above-described embodiment also allocates a stabilized laser signal of a wavelength of 1560 nm instead of the 780 nm wavelength required for the Rydberg-atom-based RF receivers because the laser signal will experience much less attenuation (<0.3 db / km, compared to ~4 db / km for the laser signal at 780 nm) when transmitted between the core network node 10 and each of the multiple base stations 20, 30, 40, 50 at this wavelength. However, those skilled in the art will understand that it is not necessary to allocate a stabilized laser signal at 1560 nm. That is, the core network node 10 can transmit a laser signal of any wavelength, but preferably transmits a laser signal with lower transmission loss compared to the laser signal having the wavelength required for the Rydberg-atom-based RF receiver. Therefore, the allocated laser signal can have a wavelength between 1260 nm and 1625 nm, or more preferably one of the original (O) band (1260 - 1360 nm), extended (E) band (1360 - 1460 nm), short (S) band (1460 - 1530 nm), conventional (C) band (1530 - 1565 nm), or long (L) band (1565 - 1625 nm). Since wavelength conversion between 780 nm and 1560 nm is relatively easy, it is beneficial to allocate a 1560 nm laser signal to the multiple base stations 20, 30, 40, 50 using the Rydberg-atom-based RF receivers that require a 780 nm laser signal.

[0037] In the above-described first embodiment, the RF receiver of each base station includes a coupling laser for generating a coupling signal. However, the telecommunication network can also be adapted to generate a signal (alternatively, or in addition to the signal used as a probe signal in each RF receiver) in the core network node that is used as a coupling signal in the RF receivers of each base station. Now, reference will be made to Figure 5Describe the second embodiment, which illustrates a central network node 10 that generates a detection signal and a coupling signal (the same reference numerals as those used in the first embodiment are used for similar components). The master laser 12 (identified as the first master laser 12 in this second embodiment), the splitter 14 (identified as the first splitter 14 in this second embodiment), the SHG 16 (identified as the first SHG 16 in this second embodiment), and the MTS 18 (identified as the first MTS 18 in this second embodiment) operate in the same manner as in the first embodiment. In this second embodiment, the core network node 10 includes a second master laser node 13, a second splitter 15, a second SHG 17, and a second MTS 19. The second master laser 13 generates a laser signal at 960 nm, and the second splitter 15, the second SHG 17, and the second MTS 19 operate to separate and stabilize the 960 nm signal (in the same manner as the first splitter 14, the first SHG 16, and the first MTS 18 operate to separate and stabilize the 1560 nm signal). The core network node 10 also includes a multiplexer 11 that multiplexes the 1560 nm and 960 nm signals for distribution by the optical network 60 to each of a plurality of base stations 20, 30, 40, 50. At each base station, the 1560 nm and 960 nm signals are amplified (by amplifiers 22, 32, 42, 52) and demultiplexed (by demultiplexers 23, 33, 43, 53). The 1560 nm signal is directed to the first SHG 24, 34, 44, 54 to be wavelength-converted to 780 nm, and the 960 nm signal is directed to the second SHG 25, 35, 45, 55 to be wavelength-converted to 480 nm. Then, the 780 nm signal is used as the detection signal in each RF receiver 26, 36, 46, 56, and then the 480 nm signal is used as the coupling signal in each RF receiver 26, 36, 46, 56.

[0038] Accordingly, this second embodiment has the advantage that both the detection signal and the coupling signal are centrally generated, stabilized, and distributed to each of the base stations 20, 30, 40, 50. Since the 960 nm signal will attenuate more severely than the 1560 nm signal during each distribution path through the optical network 60, one or more amplifiers (such as a neodymium-doped fiber amplifier (NDFA)) can be provided on each distribution path to amplify the 960 nm signal.

[0039] Now, reference will be made to Figure 6 Describe the third embodiment. Figure 6Another telecommunications network is shown, in which the probe signal and the coupling signal are generated centrally. However, in this third embodiment, the second master laser 13 generates a signal at 1248 nm, and the second SHG is replaced by a mixer. The 1248 nm signal is split by a splitter 14 into a first path and a second path. The first path directs the 1248 nm signal to the mixer, where it is mixed with the 780 nm signal from the SHG 16 to generate a 480 nm signal. This 480 nm signal is then passed to the second MTS 19 to stabilize the 1248 nm signal. The second path directs the 1248 nm signal to the multiplexer 11, which multiplexes the 1560 nm signal and the 1248 nm signal for distribution by the optical network 60 to each of a plurality of base stations 20, 30, 40, 50. At each base station 20, 30, 40, 50, the 1560 nm and 1248 nm signals are amplified (by amplifiers 22, 32, 42, 52) and demultiplexed (by demultiplexers 23, 33, 43, 53). The 1560 nm signal is passed to the SHG to be wavelength-converted to 780 nm and then passed to the RF receivers 26, 36, 46, 56 (to be used as the probe signal) and the mixers 27, 37, 47, 57, where it is mixed with the demultiplexed 1248 nm signal to generate a 480 nm signal. The 480 nm signal is then also passed to the RF receivers 26, 36, 46, 56 to be used as the coupling signal. This third embodiment has the advantage over the second embodiment in that the 1248 nm signal experiences less attenuation than the 960 nm signal, reducing the need for amplifiers on the distribution path.

[0040] In the above embodiments, the optical network 60 may use an optical fiber such as a single-mode optical fiber or a hollow-core optical fiber. The hollow-core optical fiber can be designed such that the attenuation of the signal (e.g., at 1560 nm, 1248 nm, and / or 960 nm) is less than that experienced using a single-mode optical fiber. This can also reduce the need for amplifiers on the distribution path and / or at each distribution node.

[0041] In the second and third embodiments above, multiplexers / demultiplexers are used to distribute multiple signals. However, this is not necessary, and dedicated optical fibers can be used to distribute each signal.

[0042] Those skilled in the art will understand that it is not necessary to implement the present invention in an optical network that is part of a cellular telecommunications network. That is, the present invention can be implemented with any form of telecommunications network in which laser signals are distributed from a central node to a plurality of distributed nodes via an optical network.

[0043] In addition, those skilled in the art will understand that it is not necessary for each of the multiple distributed nodes to implement a Rydberg-atom-based RF receiver. That is, the benefits of distributing a stable laser signal can be achieved in any telecommunications network where multiple distributed nodes each require a stable laser signal. Each of the multiple distributed nodes can implement an alternative form of a Rydberg-atom-based technology or any other technology that requires a stable laser signal. In addition, those skilled in the art will understand that it is not necessary for the stable laser to be used to transition electrons from the ground state to the first excited state (i.e., to probe the laser signal), and it can be used for any other electronic transition. In addition, the central node can use the above-described techniques to provide multiple stable laser signals to each of the multiple distributed nodes such that the first stable laser signal can be used as the probe laser signal while the second stable laser signal can be used as the coupling laser signal.

[0044] Those skilled in the art will also understand that it is not necessary to use a splitter in the core network node 10 because any other device capable of splitting (i.e., routing or directing) the laser signal to the local path and the multiple distribution paths can be used alternatively. This can include, for example, an optical coupler. In addition, those skilled in the art will understand that it is not necessary for the laser to generate each optical signal in the above-described embodiments. That is, another optical transmitter (or coherent optical transmitter), such as a light-emitting diode LED, can be used.

[0045] Those skilled in the art will understand that any combination of features is possible within the scope of the claimed invention.

Claims

1. A method in a telecommunication network, the telecommunication network comprising a central node, an optical network, and a plurality of distributed nodes, the method comprising the following steps: At the central node, generating a first optical signal of a first wavelength; At the central node, guiding the first optical signal into a first path for the first optical signal and a second path for the first optical signal, wherein the first path for the first optical signal is connected to a first optical stabilizer to stabilize the first optical signal generated by the central node, and the second path for the first optical signal provides the stabilized first optical signal to the optical network for distribution to each of the plurality of distributed nodes; At each of the plurality of distributed nodes, converting the stabilized first optical signal from the first wavelength to a second wavelength; and At each of the plurality of distributed nodes, using the stabilized first optical signal of the second wavelength, wherein the first wavelength has a lower transmission loss than the second wavelength.

2. The method according to claim 1, wherein, The first path for the first optical signal includes a first wavelength converter that converts the first optical signal from the first wavelength to the second wavelength before the first optical stabilizer performs stabilization.

3. The method according to claim 1 or 2, wherein The first wavelength is in the range from 1260 nm to 1625 nm.

4. The method according to claim 1, the method further comprising the following steps: At the central node, generating a second optical signal of a third wavelength; At the central node, guiding the second optical signal into a first path for the second optical signal and a second path for the second optical signal, wherein the first path for the second optical signal is connected to a second optical stabilizer to stabilize the second optical signal generated by the central node, and the second path for the second optical signal provides the stabilized second optical signal to the optical network for distribution to each of the plurality of distributed nodes; and At each of the plurality of distributed nodes, converting the stabilized second optical signal from the third wavelength to a fourth wavelength; and At each of the plurality of distributed nodes, using the stabilized second optical signal of the fourth wavelength, wherein the third wavelength has a lower transmission loss than the fourth wavelength.

5. The method according to claim 4, wherein, The first path for the second optical signal includes a second wavelength converter that converts the second optical signal from the third wavelength to the fourth wavelength before the second optical stabilizer performs stabilization.

6. The method according to claim 4 or 5, wherein The third wavelength is in the range from 1260 nm to 1625 nm.

7. The method according to claim 4, wherein, The first path for the second optical signal includes a mixer that mixes the second optical signal of the third wavelength with the first optical signal of the second wavelength after the first wavelength converter converts the first optical signal.

8. The method according to claim 1, wherein Each of the plurality of distributed nodes uses the stabilized first optical signal of the second wavelength to excite an electron of a Rydberg atom from a first state to a second state.

9. The method according to claim 8, the method further comprising the following steps: At the central node, generating a second optical signal of a third wavelength; At the central node, guiding the second optical signal into a first path for the second optical signal and a second path for the second optical signal, wherein the first path for the second optical signal is connected to a second optical stabilizer to stabilize the second optical signal generated by the central node, and the second path for the second optical signal provides the stabilized second optical signal to the optical network for distribution to each of the plurality of distributed nodes; At each of the plurality of distributed nodes, converting the stabilized second optical signal from the third wavelength to a fourth wavelength; and At each of the plurality of distributed nodes, using the stabilized second optical signal of the fourth wavelength, wherein the third wavelength has a lower transmission loss than the fourth wavelength, and each of the plurality of distributed nodes uses the stabilized second optical signal of the fourth wavelength to excite an electron of a Rydberg atom from the second state to the third state.

10. The method according to claim 8 or 9, wherein, The Rydberg atom is part of a radio frequency (RF) receiver based on Rydberg atoms.

11. The method according to claim 1, wherein, The optical network distributes the stabilized first optical signal onto a hollow-core optical fiber.

12. The method according to claim 4 or 5, wherein The optical network distributes the stabilized second optical signal onto a hollow-core optical fiber.

13. A telecommunication network, the telecommunication network comprising: A central node, the central node comprising: A first light source configured to generate a first optical signal of a first wavelength; A first optical stabilizer configured to stabilize the first optical signal; A communication interface capable of being connected to an optical network; and A first splitting unit configured to guide the first optical signal into a first path for the first optical signal and a second path for the first optical signal, wherein the first path for the first optical signal is connected to the first optical stabilizer, and the second path for the first optical signal is connected to the communication interface to provide the stabilized first optical signal to the optical network for distribution to each of a plurality of distributed nodes; and The plurality of distributed nodes configured to use the stabilized first optical signal of a second wavelength, each distributed node comprising: A wavelength converter configured to convert the stabilized first optical signal from the first wavelength to the second wavelength, wherein the first wavelength has a lower transmission loss than the second wavelength.

14. The telecommunications network according to claim 13, wherein, The central node further comprises a first wavelength converter configured to convert the first optical signal from the first wavelength to the second wavelength before the first optical stabilizer performs stabilization.

15. The telecommunications network according to claim 13 or 14, wherein The first wavelength is in the range from 1260 nm to 1625 nm.

16. The telecommunications network according to claim 13, wherein, The central node further comprises: A second light source configured to generate a second optical signal of a third wavelength; A second optical stabilizer configured to stabilize the second optical signal; and A second splitting unit configured to direct the second optical signal into a first path for the second optical signal and a second path for the second optical signal, wherein the first path for the second optical signal is connected to the second optical stabilizer, and the second path for the second optical signal is connected to the communication interface to provide the stabilized second optical signal to the optical network for distribution to each of the plurality of distributed nodes, and Each of the plurality of distributed nodes is configured to use the stabilized second optical signal at a fourth wavelength and further includes: A wavelength converter configured to convert the stabilized second optical signal from the third wavelength to the fourth wavelength, Wherein the third wavelength has a lower transmission loss than the fourth wavelength.

17. The telecommunications network according to claim 16, wherein, The central node further includes a second wavelength converter configured to convert the second optical signal from the third wavelength to the fourth wavelength before stabilization by the second optical stabilizer.

18. The telecommunications network according to claim 16 or 17, wherein, The third wavelength is in the range from 1260 nm to 1625 nm.

19. The telecommunications network according to claim 16, wherein, The first path for the second optical signal further includes a mixer for mixing the second optical signal at the third wavelength with the first optical signal at the second wavelength after the first wavelength converter converts the first optical signal.

20. The telecommunications network according to claim 13, wherein, Each of the plurality of distributed nodes uses the stabilized first optical signal at the second wavelength to excite the electrons of Rydberg atoms from a first state to a second state.

21. The telecommunications network according to claim 20, wherein, The central node further includes: A second light source configured to generate a second optical signal at a third wavelength; A second optical stabilizer configured to stabilize the second optical signal; and A second splitting unit configured to direct the second optical signal into a first path for the second optical signal and a second path for the second optical signal, wherein the first path for the second optical signal is connected to the second optical stabilizer, and the second path for the second optical signal is connected to the communication interface to provide the stabilized second optical signal to the optical network for distribution to each of the plurality of distributed nodes, and Each of the plurality of distributed nodes is configured to use the stabilized second optical signal at a fourth wavelength and further includes: A wavelength converter configured to convert the stabilized second optical signal from the third wavelength to the fourth wavelength, Wherein the third wavelength has a lower transmission loss than the fourth wavelength, and each of the plurality of distributed nodes uses the stabilized second optical signal at the fourth wavelength to excite the electrons of Rydberg atoms from the second state to the third state.

22. The telecommunications network according to claim 20 or 21, wherein, The Rydberg atoms are part of a Rydberg atom-based radio frequency (RF) receiver.

23. The telecommunications network according to claim 20, wherein, The optical network distributes the stabilized first optical signal onto a hollow-core optical fiber.

24. The telecommunications network according to claim 20, wherein, The optical network distributes the stable second optical signal onto the hollow-core optical fiber.

25. A computer-readable medium storing a computer program comprising instructions that cause a telecommunications network according to any one of claims 13 to 24 to perform a method according to any one of claims 1 to 12.

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