Optical fiber telephone system with single-end power supply

Abstract

The invention discloses a single-end power supply optical fiber telephone system, which comprises a power supply telephone end, a non-power supply telephone end and a single-mode optical fiber for connecting the power supply telephone end and the non-power supply telephone end, and is characterized in that the power supply telephone end comprises a power supply unit, an energy supply light source unit, a voice sending unit, a first voice receiving unit and a first wavelength division multiplexer; the power supply unit supplies power to the energy supply light source unit, the voice sending unit and the first voice receiving unit; the non-power-supply telephone end comprises a light energy conversion power supply unit, a passive voice sending unit, a second voice receiving unit and a second wavelength division multiplexer, and the light energy conversion power supply unit provides a power supply for the second voice receiving unit; one end of the single-mode optical fiber is in optical fiber connection with the voice sending unit, the first voice receiving unit and the energy supply light source unit through the first wavelength division multiplexer, and the other end of the single-mode optical fiber is in optical fiber connection with the light energy conversion power supply unit, the second voice receiving unit and the passive voice sending unit through the second wavelength division multiplexer.

Description

Technical Field

[0001] The invention relates to the field of optical fiber communication, and in particular to an optical fiber telephone system with single-end power supply. Background Art

[0002] Fiber optic communication is a technology that uses light to transmit information in an optical fiber medium. It has the advantages of long transmission distance, anti-electromagnetic interference, large transmission bandwidth, and high reliability. It is widely used in the Internet, television transmission, military communications and other fields. For areas with harsh environments such as underground mines and pipeline corridors, communication facilities are affected, resulting in restrictions on the application of traditional communication methods such as radio waves and microwave communications. The advantages of communication methods based on fiber optic communication technology continue to emerge. The emergence of fiber optic telephones solves the problem of point-to-point communication. Compared with traditional telephone communications, it can not only realize more voice data transmission at the same time and ensure stable and reliable communication, but also realize barrier-free communication in areas with harsh environments, becoming the preferred method for long-distance voice communication.

[0003] The working principle of fiber-optic telephone is to convert the electrical signal at the transmitting end into an optical signal through two photoelectric conversions, and then convert it back into an electrical signal at the receiving end. With the continuous development of communication technology, the use of wavelength division multiplexing technology can combine multi-wavelength optical signals in a single optical fiber for transmission, which not only improves the transmission capacity and network transmission efficiency, but also reduces the operating cost. It can realize a variety of services such as telephone and video, which is very suitable for point-to-point fiber-optic voice and video communication.

[0004] However, most fiber optic devices are passive devices, which limits the development of fiber optic sensing technology to a certain extent. The introduction of active optical devices in underground mines and pipeline corridors often requires a continuous external power supply, which also increases the cost of the system. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a single-end powered fiber optic telephone system that realizes two-way voice transmission by powering one end, the single-end powered fiber optic telephone system comprising:

[0006] A power supply telephone end, comprising a power supply unit, a power supply light source unit, a voice sending unit, a first voice receiving unit and a first wavelength division multiplexer, wherein the power supply unit provides power supply for the power supply light source unit, the voice sending unit and the first voice receiving unit;

[0007] The non-powered telephone terminal includes a light energy conversion power supply unit, a passive voice sending unit, a second voice receiving unit and a second wavelength division multiplexer, wherein the light energy conversion power supply unit provides power supply for the second voice receiving unit;

[0008] A single-mode optical fiber connects the powered telephone end and the non-powered telephone end, one end of which is optically connected to the voice sending unit, the first voice receiving unit, and the power supply light source unit through the first wavelength division multiplexer, and the other end of which is optically connected to the light energy conversion power supply unit, the second voice receiving unit, and the passive voice sending unit through the second wavelength division multiplexer.

[0009] The voice sending unit provides the second voice receiving unit with signal light having a central wavelength of the first wavelength λ1, the passive voice sending unit provides the first voice receiving unit with signal light having a central wavelength of the second wavelength λ2, and the power supply light source unit provides the light energy conversion power supply unit with energy light having a central wavelength of the third wavelength λ3.

[0010] Furthermore, the voice sending unit includes a microphone, a signal converter and an optical transmitting end electrically connected in sequence, and the optical transmitting end is connected to the first wavelength division multiplexer optical fiber; the second voice receiving unit includes an optical receiving end and a power amplifier electrically connected in sequence, and a second earpiece and a second speaker electrically connected to the power amplifier, and the optical receiving end is connected to the second wavelength division multiplexer optical fiber.

[0011] Furthermore, the passive voice sending unit includes a reflection unit and an optical fiber coil connected in sequence by optical fiber, and the optical fiber coil is connected to the second wavelength division multiplexer by optical fiber; the first voice receiving unit includes a first photodetector and a demodulation module electrically connected in sequence, a first earpiece and a first speaker electrically connected to the demodulation module, and an interference module connected to the first photodetector by optical fiber, and the interference module is connected to the first wavelength division multiplexer by optical fiber.

[0012] Furthermore, the light energy conversion power supply unit includes a second photodetector and a DC power supply unit which are electrically connected in sequence, the second photodetector is optically connected to the second wavelength division multiplexer, and the DC power supply unit is electrically connected to the second voice receiving unit.

[0013] Furthermore, part of the energy light with a central wavelength of the third wavelength λ3 of the power supply light source unit at the powered telephone end is used to perform Raman amplification on signal light with a central wavelength of the first wavelength λ1 and signal light with a central wavelength of the second wavelength λ2; the other part is converted into electrical energy at the non-powered telephone end and provides power supply for the second voice receiving unit at the non-powered telephone end.

[0014] Further, the energy light with a central wavelength of the third wavelength λ3 provided by the energy supply light source unit enhances the signal light with a central wavelength of the first wavelength λ1 and the signal light with a central wavelength of the second wavelength λ2 through the Raman amplification effect, and the Raman gain is expressed by the following formula:

[0015]

[0016] Among them G v (Δv) is the Raman gain, g v (Δv) is the Raman gain coefficient, is the optical power of the energy source unit, L eff is the effective fiber length.

[0017] Further, the frequency difference between the energy light having the third wavelength λ3 as the center wavelength and the signal light having the first wavelength λ1 as the center wavelength and the signal light having the second wavelength λ2 as the center wavelength is expressed by the following formula:

[0018]

[0019] Furthermore, the Raman amplification efficiency δ R It is expressed by the following formula:

[0020]

[0021] Furthermore, the energy light of the other part with the central wavelength of the third wavelength λ3 is received by the second photodetector at the non-powered telephone end and converted into electrical energy, and the photoelectric conversion efficiency δ of the energy light with the central wavelength of the third wavelength λ3 is E It is expressed by the following formula:

[0022]

[0023] Wherein, CE is the photoelectric conversion coefficient of the second photodetector, and

[0024] CE=QE×(1-e -αd ),

[0025] Where QE is the quantum efficiency; α is the absorption coefficient; and d is the material thickness.

[0026] Furthermore, the comprehensive utilization rate of Raman amplification efficiency and photoelectric conversion efficiency δ Total It is expressed by the following formula:

[0027]

[0028] The single-end powered fiber optic telephone system provided by the present invention connects the fiber optic telephones at both ends through the single-mode optical fiber, and only provides power supply to the powered telephone end, and remotely powers the non-powered telephone end through the energy light of the powered telephone end. The non-powered telephone end does not require an additional power supply, which greatly saves costs and reduces energy consumption.

[0029] Moreover, the present invention utilizes wavelength division multiplexing technology and uses only one core optical fiber to transmit signal light and energy light of different wavelengths in the same core, and based on the use of optical signals of the same wavelength between transmission and reception, ensures stable sound signal transmission over long distances. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic diagram of a single-ended powered fiber optic telephone system of the present invention.

[0032] Figure 2 A schematic diagram of the application of the single-ended powered fiber optic telephone system of the present invention underground. DETAILED DESCRIPTION

[0033] The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the description 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.

[0034] The directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front”, “back”, “top”, “bottom”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, or are the directions or positional relationships in which the inventive product is usually placed when used. They are only for the convenience of description and simplified description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0035] The terms "comprises," "comprising," or any other variations thereof, are intended to cover a non-exclusive inclusion of the elements listed and may also include additional elements not expressly listed.

[0036] See also Figure 1 The present invention provides a single-ended powered optical fiber telephone system, comprising:

[0037] The power supply telephone terminal 100 includes a power supply unit 110, a power supply light source unit 120, a voice sending unit 130, a first voice receiving unit 140 and a first wavelength division multiplexer 150, wherein the power supply unit 110 provides power supply for the power supply light source unit 120, the voice sending unit 130 and the first voice receiving unit 140;

[0038] The non-powered telephone terminal 200 includes a light energy conversion power supply unit 220, a passive voice sending unit 240, a second voice receiving unit 230 and a second wavelength division multiplexer 210, wherein the light energy conversion power supply unit 220 provides power supply for the second voice receiving unit 230;

[0039] The single-mode optical fiber 300 connects the powered telephone terminal 100 and the non-powered telephone terminal 200, one end of which is connected to the voice sending unit 130, the first voice receiving unit 140, and the power supply light source unit 120 through the first wavelength division multiplexer 150, and the other end of which is connected to the light energy conversion power supply unit 220, the second voice receiving unit 230, and the passive voice sending unit 240 through the second wavelength division multiplexer 210.

[0040] Among them, the voice sending unit 130 provides signal light of the first wavelength λ1 to the second voice receiving unit 230, the passive voice sending unit 240 provides signal light of the second wavelength λ2 to the first voice receiving unit 140, and the power supply light source unit 120 provides energy light of the third wavelength λ3 to the light energy conversion power supply unit 220.

[0041] The voice sending unit 130 includes a microphone 131, a signal converter 132 and an optical transmitting end 133 electrically connected in sequence, and the optical transmitting end 133 is optically connected to the first wavelength division multiplexer 150; the second voice receiving unit 230 includes an optical receiving end 231 and a power amplifier 232 electrically connected in sequence, and a second earpiece 233 and a second speaker 234 electrically connected to the power amplifier 232, and the optical receiving end 231 is optically connected to the second wavelength division multiplexer 210.

[0042] The passive voice sending unit 240 includes a reflection unit 241 and an optical fiber coil 242 connected in sequence by optical fiber, and the optical fiber coil 242 is optically connected to the second wavelength division multiplexer 210; the first voice receiving unit 140 includes a first photodetector 142 and a demodulation module 143 electrically connected in sequence, a first earpiece 144 and a first speaker 145 electrically connected to the demodulation module 143, and an interference module 141 connected to the first photodetector 142 by optical fiber, and the interference module 141 is optically connected to the first wavelength division multiplexer 150.

[0043] The light energy conversion power supply unit 220 includes a second photodetector 221 and a DC power supply unit 222 which are electrically connected in sequence. The second photodetector 221 is optically connected to the second wavelength division multiplexer 210 , and the DC power supply unit 222 is electrically connected to the second voice receiving unit 230 .

[0044] Part of the energy light of the third wavelength λ3 of the power supply light source unit 120 of the powered telephone end 100 is used to perform Raman amplification on the signal light of the first wavelength λ1 and the signal light of the second wavelength λ2; the other part is converted into electrical energy at the non-powered telephone end 200 and provides power for the second voice receiving unit 230 of the non-powered telephone end 200.

[0045] In this embodiment, the signal light having the first wavelength λ1 as the center wavelength and the signal light having the second wavelength λ2 as the center wavelength are both signal lights having center wavelengths within the C band.

[0046] More specifically, the output end of the power supply unit 110 is connected to the power supply light source unit 120, and the power supply light source unit 120 outputs high-power energy light with a central wavelength of the third wavelength λ3. In this embodiment, the energy light with a central wavelength of the third wavelength λ3 is selected as energy light with a central wavelength of 1455nm, and is connected to the first wavelength division multiplexer 150 through the single-mode optical fiber 300.

[0047] The first wavelength division multiplexer 150 is connected to the second wavelength division multiplexer 210 through the single-mode optical fiber 300, and the high-power 1455nm energy light with a central wavelength of the third wavelength λ3 can be Raman amplified with the central wavelengths of the first wavelength λ1 and the second wavelength λ2 in the C band transmitted by the optical transmitting end 133 and the optical fiber coil 242 during the transmission of the single-mode optical fiber 300.

[0048] The input end of the first wavelength division multiplexer 150 and the output end of the second wavelength division multiplexer 210 are divided into three paths. The energy light output by the energy supply light source unit 120 is connected to the second photodetector 221 through the single-mode optical fiber 300, and then connected to the DC power supply unit 222. The DC power supply unit 222 provides power supply for the optoelectronic devices of the second voice receiving unit 230.

[0049] The output end of the microphone 131 of the voice sending unit 130 of the power supply telephone end 100 is connected to the signal converter 132, the output end of the signal converter 132 is connected to the optical sending end 133, and the output end of the optical sending end 133 and the input end of the interference module 141 are connected to the first wavelength division multiplexer 150 together.

[0050] The optical transmitting end 133 outputs signal light with a specific central wavelength of the first wavelength λ1 in the C band, and then enters the second wavelength division multiplexer 210, and then connects to the optical receiving end 231 through the single-mode optical fiber 300 at the output end of the second wavelength division multiplexer 210. The optical receiving end 231 receives the signal light with a central wavelength of the first wavelength λ1, and connects to the second handset 233 and the second speaker 234 by connecting to the power amplifier 232, thereby realizing voice transmission from the powered telephone end 100 to the non-powered telephone end 200.

[0051] After the optical fiber coil 242 of the non-powered telephone end 200 is subjected to sound vibration, the phase of the signal light with a specific central wavelength of the second wavelength λ2 in the C band is changed, and the optical signal with the changed wavelength is transmitted to the second wavelength division multiplexer 210 through the reflection unit 241, and then the output end of the second wavelength division multiplexer 210 is connected to the first wavelength division multiplexer 150 through the single-mode optical fiber 300, and the first wavelength division multiplexer 150 is connected to the interference module 141 through the optical fiber, and the output end of the interference module 141 is connected to the first photodetector 142, and the first photodetector 142 is connected to the demodulation module 143 and completes the restoration of the voice signal of the passive voice sending unit 240 of the non-powered telephone end 200. The demodulation module 143 realizes the voice transmission from the non-powered telephone end 200 to the powered telephone end 100 by connecting the first receiver 144 and the first speaker 145.

[0052] In this embodiment, the first wavelength division multiplexer 150 and the power supply light source unit 120, the first wavelength division multiplexer 150 and the optical transmitting end 133, the first wavelength division multiplexer 150 and the interference module 141, the second wavelength division multiplexer 210 and the second photodetector 221, the second wavelength division multiplexer 210 and the optical receiving end 231, and the second wavelength division multiplexer 210 and the optical fiber coil 242 are also connected using the single-mode optical fiber 300; the second photodetector 221 and the DC power supply unit 222, the microphone 131 and the signal converter 132, the optical receiving end 231 and the power amplifier 232, the power amplifier 232 and the second earpiece 233 and the second speaker 234, the first photodetector 142 and the demodulation module 143, the demodulation module 143 and the first earpiece 144 and the first speaker 145 are connected through a power line.

[0053] In more detail, in this embodiment, the power supply light source unit 120 is used to: emit high-power energy light with a central wavelength of a third wavelength λ3 of 1455nm, first to Raman amplify the C-band optical signal between the powered telephone terminal 100 and the non-powered telephone terminal 200, and the remaining part to power the non-powered telephone terminal 200.

[0054] The second photodetector 221 is used for: after the signal light with the first wavelength λ1 as the central wavelength and the second wavelength λ2 as the central wavelength are removed by the second wavelength division multiplexer 210, the photodiode of the second photodetector 221 receives the signal as an electrical signal and supplies it to the DC power supply unit 222, and the DC power supply unit 222 supplies power to the second voice receiving unit 230 of the non-powered telephone end 200.

[0055] The optical transmitting end 133 is used to: modulate the electrical signal input from the microphone 131 via the signal converter 132, convert it into a signal light with a center wavelength of the first wavelength λ1 within the C band, and further transmit the voice information of the powered telephone end 100 to the non-powered telephone end 200.

[0056] The optical receiving end 231 is used to convert the received signal light of the first wavelength λ1 of the central wavelength in the C band into an electrical signal through phase demodulation, amplitude demodulation and other methods, and then extract the original signal from the electrical signal amplified by the power amplifier 232 for use in the second earpiece 233 and the second speaker 234.

[0057] The optical fiber coil 242 is used for: when the sound wave propagates to the optical fiber coil 242, it causes a small strain on the optical fiber, which in turn causes the refractive index of the optical fiber itself to change, thereby changing the phase of the signal light with a central wavelength of the second wavelength λ2 in the C band transmitted in the optical fiber. The signal light with a central wavelength of the second wavelength λ2 after the phase change passes through the reflection unit 241 and enters the second wavelength division multiplexer 210, and finally reaches the power supply telephone terminal 100. After the interference of the interference module 141, the photoelectric conversion of the first photodetector 142, and the demodulation of the demodulation module 143, the original voice information is obtained, and finally the voice is answered through the first receiver 144 and the first speaker 145.

[0058] In summary, in the present invention, the microphone 131, the signal converter 132, the optical transmitting end 133, the first wavelength division multiplexer 150, the single-mode optical fiber 300, the second wavelength division multiplexer 210, the optical receiving end 231, the power amplifier 232, the second handset 233, and the second speaker 234 are a unidirectional voice transmission line from the powered telephone end 100 to the non-powered telephone end 200. The electrical signal is converted into an optical signal and then converted into an electrical signal through the optical transmitting end 133 and the optical receiving end 231. The signal light with a central wavelength of the first wavelength λ1 in a specific C band transmitted between the two ends of the optical fiber telephone remains unchanged after passing through the first wavelength division multiplexer 150 and the second wavelength division multiplexer 210. The original information is obtained by demodulation, which can reduce signal distortion.

[0059] In the present invention, the optical fiber coil 242, the reflection unit 241, the second wavelength division multiplexer 210, the single-mode optical fiber 300, the first wavelength division multiplexer 150, the interference module 141, the first photodetector 142, the demodulation module 143, the first receiver 144, and the first speaker 145 are a unidirectional voice transmission line from the non-powered telephone end 200 to the powered telephone end 100. The collected sound signals are directly converted into phase changes through the optical fiber coil 242. These signals are finally demodulated to obtain the original sound waveform, and voice transmission can be achieved at the non-powered telephone end 200 without power supply.

[0060] See also Figure 2 The present invention is applied in harsh environment areas such as underground mines, pipeline corridors, or remote areas with poor signals. Through the single-ended power supply fiber optic telephone system, one-way power supply can be realized between points, and long-distance real-time and accurate calls can be completed.

[0061] In this example, based on the single-ended powered fiber optic telephone system, the high-power optical conversion efficiency of 1455 nm with a central wavelength of the third wavelength λ3 is calculated. The light source of 1455 nm with a central wavelength of the third wavelength λ3 has two uses. First, it performs Raman amplification on the signal light with a central wavelength of the first wavelength λ1 in the C band and the signal light with a central wavelength of the second wavelength λ2, and the remaining light is converted into electrical energy by the second photodetector 221.

[0062] In this embodiment, the energy light of 1455 nm with a central wavelength of the third wavelength λ3 provided by the energy supply light source unit 120 can enhance the signal light with a central wavelength of the first wavelength λ1 and the signal light with a central wavelength of the second wavelength λ2 through the Raman amplification effect, wherein the Raman gain is expressed by the following formula:

[0063]

[0064] Among them G v (Δv) is the Raman gain, g v (Δv) is the Raman gain coefficient, is the optical power of the energy supply light source unit 120, L eff is the effective fiber length.

[0065] Furthermore, the frequency difference between the energy light having the third wavelength λ3 as the center wavelength and the signal light having the first wavelength λ1 as the center wavelength and the signal light having the second wavelength λ2 as the center wavelength is expressed by the following formula:

[0066]

[0067] Raman amplification efficiency δ R It is expressed by the following formula:

[0068]

[0069] Further, part of the energy light with a central wavelength of the third wavelength λ3 of the power supply light source unit 120 of the power supply telephone end 100 is used to perform Raman amplification on the signal light with a central wavelength of the first wavelength λ1 and the signal light with a central wavelength of the second wavelength λ2; the other part is converted into electrical energy at the non-power supply telephone end 200 and provides power supply to the second voice receiving unit 230 of the non-power supply telephone end 200, and the other part of the energy light with a central wavelength of the third wavelength λ3 is received by the second photodetector 221 of the non-power supply telephone end 200 and converted into electrical energy, and the photoelectric conversion efficiency δ of the energy light with a central wavelength of the third wavelength λ3 is E It is expressed by the following formula:

[0070]

[0071] The ability of the photodiode of the second photodetector 221 to convert incident photons into electron pairs can be represented by the conversion efficiency CE (Conversion Efficiency), that is, CE is the photoelectric conversion coefficient of the second photodetector 221, and

[0072] CE=QE×(1-e -αd ),

[0073] Among them, QE is quantum efficiency, which is mainly related to the composition ratio and manufacturing process; α is the absorption coefficient, which is related to the band structure of the material and the wavelength of the incident light; d is the material thickness, that is, the thickness of the photodiode. In this embodiment, the photodiode is an indium gallium arsenide diode.

[0074] Therefore, the comprehensive utilization rate of Raman amplification efficiency and photoelectric conversion efficiency δ is obtained TotalIt is expressed by the following formula:

[0075]

[0076] The beneficial effects of the single-ended powered optical fiber telephone system provided by the present invention are as follows:

[0077] 1. The present invention connects the fiber optic telephones at both ends through a single-mode optical fiber, only provides power supply to the powered telephone end, and remotely powers the non-powered telephone end through the energy light of the powered telephone end. The non-powered telephone end does not need additional power supply, which greatly saves costs and reduces energy consumption.

[0078] 2. The present invention uses high-power 1455nm wavelength energy light to firstly perform Raman amplification of the transmitted C-band light source, and the remaining light energy is converted into electrical energy at the receiving end to provide power supply for the second voice receiving part of the non-powered telephone end.

[0079] 3. The present invention uses two sets of voice transmission methods, one of which is the conversion of electrical signals into optical signals and then into electrical signals. It uses the signal light with a first wavelength λ1 as the center wavelength in the C-band for long-distance transmission, and changes the light intensity in the sound-transmitting single-mode optical fiber by changing the frequency of the electrical signal. Finally, the received light is demodulated into the original electrical signal through a power amplifier to obtain the original sound information. The other set modulates the phase change of the signal light with a second wavelength λ2 as the center wavelength in the C-band by sound vibration, demodulates it into an electrical signal, and finally restores the original sound information.

[0080] 4. The present invention utilizes wavelength division multiplexing technology and uses only one core optical fiber to transmit signal light and energy light of different wavelengths in the same core, and based on the use of optical signals of the same wavelength between transmission and reception, ensures the stable transmission of sound signals over long distances.

[0081] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A single-ended powered fiber optic telephone system, characterized in that: include: A power supply telephone end, comprising a power supply unit, a power supply light source unit, a voice sending unit, a first voice receiving unit and a first wavelength division multiplexer, wherein the power supply unit provides power supply for the power supply light source unit, the voice sending unit and the first voice receiving unit; The non-powered telephone terminal includes a light energy conversion power supply unit, a passive voice sending unit, a second voice receiving unit and a second wavelength division multiplexer, wherein the light energy conversion power supply unit provides power supply for the second voice receiving unit; A single-mode optical fiber connects the powered telephone end and the non-powered telephone end, one end of which is optically connected to the voice sending unit, the first voice receiving unit, and the power supply light source unit through the first wavelength division multiplexer, and the other end of which is optically connected to the light energy conversion power supply unit, the second voice receiving unit, and the passive voice sending unit through the second wavelength division multiplexer. The voice sending unit provides the second voice receiving unit with signal light having a central wavelength of the first wavelength λ1, the passive voice sending unit provides the first voice receiving unit with signal light having a central wavelength of the second wavelength λ2, and the power supply light source unit provides the light energy conversion power supply unit with energy light having a central wavelength of the third wavelength λ3.

2. The single-ended powered fiber optic telephone system according to claim 1, characterized in that: The voice sending unit includes a microphone, a signal converter and an optical transmitting end electrically connected in sequence, and the optical transmitting end is connected to the first wavelength division multiplexer optical fiber; the second voice receiving unit includes an optical receiving end and a power amplifier electrically connected in sequence, and a second earpiece and a second speaker electrically connected to the power amplifier, and the optical receiving end is connected to the second wavelength division multiplexer optical fiber.

3. The single-ended powered fiber optic telephone system according to claim 1, characterized in that: The passive voice sending unit includes a reflection unit and an optical fiber coil connected in sequence by optical fiber, and the optical fiber coil is connected to the second wavelength division multiplexer by optical fiber; the first voice receiving unit includes a first photodetector and a demodulation module electrically connected in sequence, a first earpiece and a first speaker electrically connected to the demodulation module, and an interference module connected to the first photodetector by optical fiber, and the interference module is connected to the first wavelength division multiplexer by optical fiber.

4. The single-ended powered fiber optic telephone system according to claim 1, characterized in that: The light energy conversion power supply unit includes a second photodetector and a DC power supply unit which are electrically connected in sequence, the second photodetector is optically connected to the second wavelength division multiplexer, and the DC power supply unit is electrically connected to the second voice receiving unit.

5. The single-ended powered fiber optic telephone system according to claim 1, characterized in that: Part of the energy light with a central wavelength of the third wavelength λ3 of the power supply light source unit at the powered telephone end is used to perform Raman amplification on the signal light with a central wavelength of the first wavelength λ1 and the signal light with a central wavelength of the second wavelength λ2; the other part is converted into electrical energy at the non-powered telephone end and provides power supply for the second voice receiving unit at the non-powered telephone end.

6. The single-ended powered fiber optic telephone system according to claim 5, characterized in that: The energy light with the central wavelength λ3 provided by the energy supply light source unit enhances the signal light with the central wavelength λ1 and the signal light with the central wavelength λ2 through the Raman amplification effect, and the Raman gain is expressed by the following formula: Among them G v (Δv) is the Raman gain, g v (Δv) is the Raman gain coefficient, is the optical power of the energy source unit, L eff is the effective fiber length.

7. The single-ended powered fiber optic telephone system according to claim 6, characterized in that: The frequency difference between the energy light having the third wavelength λ3 as the center wavelength and the signal light having the first wavelength λ1 as the center wavelength and the signal light having the second wavelength λ2 as the center wavelength is expressed by the following formula:

8. The single-ended powered fiber optic telephone system according to claim 6, characterized in that: Raman amplification efficiency δ R It is expressed by the following formula:

9. The single-ended powered fiber optic telephone system according to claim 6, characterized in that: The energy light of the other part with the central wavelength of the third wavelength λ3 is received by the second photodetector at the non-powered telephone end and converted into electrical energy. The photoelectric conversion efficiency δ of the energy light with the central wavelength of the third wavelength λ3 is E It is expressed by the following formula: Wherein, CE is the photoelectric conversion coefficient of the second photodetector, and CE=QE×(1-e-αd), Where QE is the quantum efficiency; α is the absorption coefficient; and d is the material thickness.

10. The single-ended powered fiber optic telephone system according to claim 9, characterized in that: The comprehensive utilization rate of Raman amplification efficiency and photoelectric conversion efficiency δ Total It is expressed by the following formula:

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