RU2782236C1 - Photoelectric receiving device of optical communication line - Google Patents

Abstract

FIELD: communication technology.

SUBSTANCE: invention relates to communication technology and can be used in optical communication systems. To achieve the effect, the photoelectric receiver of the optical communication line includes an information radiation concentrator, in the focus of which a high-speed infrared photodiode is installed, connected to an electronic information signal processing unit, the output of which is intended for connection to the input of the active equipment of an autonomous communication node. The photocell is installed in front of the information radiation concentrator and connected to the device for converting and accumulating electricity, in which a DC-converter-stabilizer (18) of DC voltage and a charge regulator (19) connected in series are installed in front of the energy storage device (20).

EFFECT: absence of the need for a wired power supply line.

10 cl, 2 dwg

Description

The invention relates to the fields of optical communication and wireless power transmission, in particular to laser information transmission systems, and can be used to organize the reception and transmission of data within line of sight via an atmospheric or space optical channel at an autonomous communication node, devoid of a power supply for communication equipment.

In the field of data transmission, an increasing niche is occupied by fiber optic systems, characterized by high data transmission speed, long range, and noise immunity. At present, developments have appeared in the field of light energy transmission through optical fiber for the purpose of photoelectric conversion at the terminal device for low-current power supply of the terminal device equipment, eliminating the need to supply electricity through metal wires, which reduces noise immunity and increases the cost of laying communication networks. In cases where it is impossible or impractical to lay a fiber optic line, an atmospheric optical communication line (AOLS) is installed. The use of AOLS is promising when communication nodes are within line of sight, especially if at least one of them is located on a moving object, or when a temporary communication line is required.

A device for an optical receiver of a laser communication line is known (see patent RU 2126592, IPC H04V 10/06, publ. 20.02.1999), containing an optical receiving system (OPS), a holographic reflective filter, a light filter, the first and second photodetectors arranged in series on the optical axis , the outputs of which are electrically connected to the processing device. The holographic reflective filter is located on the optical axis at an angle a to the axis between the OPS and the light filter.

The device takes into account the change in the background environment in the process of receiving a message, however, it requires the presence of a power source in the device for its operation.

A radiation receiver of a laser-beam control channel is known (see patent RU 196583, IPC G01J 1/02, publ. 03/05/2020), containing a single-lens lens and a silicon photodiode installed in the housing. The lens of the objective is made of colored optical infrared (IR) glass with a lower passband limit close to the wavelength of the laser emitter of 1.06 μm, for example, colored optical IR glass of the IKS970 brand. The implementation of the lens of the objective of colored optical IR glass allows you to simplify the design of the radiation receiver and increase the transmittance of the lens.

The known receiver of the laser control channel is designed to create laser teleorientation systems for moving objects and, due to the very low power of the received radiation, cannot be used to create full-fledged optical communication lines with wireless power supply.

A photoelectric receiver of an optical communication system is known (see patent RU 2154909, IPC H04V 10/12, publ. 08/20/2000), containing a superconducting photodetector with properties that recover after annealing, change under radiation and electromagnetic irradiation, a cryogenic system, a unit for installing and stabilizing a working point and annealing, and demodulator.

The well-known photoelectric receiver provides an increase in sensitivity to optical radiation in a wide spectral range due to the high steepness of the superconducting transition. A disadvantage of the known photoelectric receiver is the complexity of its design and significant resource or energy consumption of the cryogenic system and annealing unit, which prevents its use on an autonomous communication node.

A photoelectric receiver of an optical communication line is known (see patent RU 2170491, IPC H04V 10/12, publ. mechanically with a matrix, a displacement unit, a control unit that calculates the coordinates of the energy center of the optical radiation spot on the specified matrix and generates a mismatch signal between the coordinates of the energy center of the optical radiation spot on the matrix and the center of the receiving aperture of the receiver.

The advantage of the known photoelectric receiver is the use of a matrix of optical sensors in its composition, which allows for precise and dynamically adjustable adjustment of the position of the radiation receiver and, with a reduced divergence of optical radiation, to reduce the requirements for transmitter power, or increase the communication range, or increase the speed and quality of information transmission. . A disadvantage of the known photoelectric receiving device is a large number of optoelectronic components, which reduces its reliability, as well as significant power consumption for the needs of the movement unit, which prevents its use in the absence of a wireless power reception channel.

A photoelectric receiving device for atmospheric optical communication is known (patent RU 2174741, IPC H04V 10/10, publ. 10.10.2001), including a multi-aperture receiving antenna consisting of N (where N ≥ 2) receiving lenses connected using a fiber-receiving bus , made in the form of N optical fibers, with a receiver, while the input ends of the optical fibers are installed at the focus, respectively, of the N receiving lenses, and the output ends of the N optical fibers are installed in the focal plane of the collimating lens of the receiving device. The receiving device also contains sequentially installed behind the collimating lens optically and mechanically connected a disk for automatically adjusting the gain of the optical signal, an interference filter, a focusing lens, a photodetector, a normalizing amplifier, an information flow formation unit, an amplifier, a threshold unit, an actuator, a drive control unit, on which the automatic optical gain control dial is installed.

The advantage of the known receiving device is its ability to provide effective compensation for signal fluctuations caused by atmospheric turbulence due to a certain way arranged receiving sub-apertures, increasing the reliability of operation under any atmospheric conditions. The disadvantages of the known device include the loss of part of the received radiation due to the spaced nature of the receiving subapertures - receiving lenses, in which the radiation falling between the surfaces of the lenses does not participate in the generation of the information signal, which necessitates the use of more powerful radiation sources and leads to a decrease in energy device efficiency.

A photoelectric receiver of an optical communication line is known (see patent RU 56097, IPC H04V 11/00, H04V 10/10, publ. 27.08.2006), including an infrared receiver, a conversion unit containing an amplifier, a signal comparison device (comparator), an electronic key. The infrared receiver is additionally equipped with an individual parabolic reflector with a lens, and the infrared receiver is permanently installed within the line of sight.

The advantage of the known receiving device is the simplicity of its design. As a disadvantage, one can point to the non-optimal location relative to each other of the concentrating elements - the lens and the parabolic mirror, which have duplicate functions.

A photoelectric receiver of a wireless optical communication line is known (see patent RU 2451397, IPC H04V 10/10, publ. 05/02/2012), including a focusing lens, a narrow-band light filter and a photodetector located one after the other, while a matrix concentrator of optical radiation is installed in the photodetector , consisting of a matrix of short-focus focusing lens elements and a matrix of prism deflecting elements.

Known photoelectric receiver allows you to concentrate the incoming information optical radiation on the photosensitive surface of the photodetector of a small area, even if the direction of incidence of radiation from the optical axis of the concentrator. The disadvantages of the known device are a large number of surfaces of the optical concentrating system in the path of radiation, which leads to spurious reflections on these surfaces and the weakening of the optical information signal, as well as the need for a power source in the device.

Known radiation receiver laser-beam control channel (see patent RU 157846, IPC G01J 1/02, publ. the lower limit of the bandwidth, close to the wavelength of the laser emitter 1.06 µm, having a bandwidth of 0.96 µm to 2.4 µm.

The advantage of the known receiver is the simplification of the design, as a result of which the transmittance of the lens has increased and the labor intensity of manufacturing and the cost of the receiver have decreased by reducing the number and simplifying its structural elements. The disadvantages include the inability of the single-lens design of the lens to effectively concentrate radiation on the photodiode, the direction of propagation of which deviates from the optical axis of the lens.

A photoelectric receiver of an optical communication line is known (see application JP 2009027215, IPC H04B 10/04, H01L 31/0232, H01L 31/10, H04B 10/02, H04B 10/06, H04B 10/14, publ. 05.02.2009 ), coinciding with the present technical solution for the largest number of essential features and taken as a prototype. The prototype photoelectric receiving device includes an information radiation concentrator, consisting of a focusing lens, in the focus of which a photodiode is installed for receiving information light, connected to an electronic information signal processing unit, the output of which is intended for connection to the input of active equipment of an autonomous communication node, a photoelectric converter for receiving energy of light, equipped with an electrode for removing electricity and biasing the photodiode, and connected by an electrode to an electricity storage device in the form of a capacitor connected to the photodiode and the photoelectric converter at the point of their serial connection by the anode of one to the cathode of the other, while the other end of the capacitor is electrically connected to the ground. The saturation current of the photoelectric converter must be greater than the saturation current of the photodiode. Radiation is supplied to the photodiode and photoelectric converter by means of an optical fiber and is focused by a lens. The photosensitive surfaces of the photodiode and the photoelectric converter can be displaced relative to each other in the plane of the substrate, in which case an illumination bundle of two optical fibers is used, or the semiconductor layers of the photodiode can be formed on the surface of the photoelectric converter grown on the carrier substrate, in this case one optical fiber is used , along which signal and supply radiation propagate simultaneously, and their wavelengths differ.

The objective of this technical solution is to develop a photoelectric receiver of an optical communication line that would not require both a wired power supply line and the use of an energy storage device with large weight and size characteristics for long-term power supply of an autonomous communication node.

The problem is solved by the fact that the photoelectric receiver of the optical communication line includes at least one information radiation concentrator, in the focus of which there is a photodiode connected to an electronic information signal processing unit, the output of which is intended for connection to the input of the active equipment of an autonomous communication node, at least at least one photoelectric converter for receiving radiation energy, equipped with electrodes for removing electricity and connected by electrodes to an electricity storage device. What is new in the photoelectric receiver is that a photoelectric converter designed to receive high-power laser radiation is installed in front of the information radiation concentrator, the photodiode is made in the form of a high-speed infrared photodiode, the electronic information signal processing unit includes an amplifier, a comparator, a Schmidt trigger and a decoder connected in series, and a series-connected DC-converter-DC voltage stabilizer and a charge regulator for the electric power storage device are installed in front of the electric power storage device.

The concentrator can be made in the form of a focusing parabolic mirror.

The concentrator can be made in the form of a conical focon, in particular, pyramidal, with a focusing lens placed in the plane of the wide edge of the focon and inscribed in its aperture.

The focusing lens can be made in the form of a Fresnel lens.

The focusing lens can be made in the form of a plano-convex lens.

The focon can be made with a mirrored inner surface. The focon can be made with a blackened matte inner surface.

A light filter can be installed in front of the fast infrared photodiode.

The high-speed photodiode can be made on the basis of an avalanche or pin structure based on Ge or on the basis of InGaAs semiconductor structures with a spectral absorption band in the infrared region.

Both electrodes on opposite surfaces of the photoelectric converter for receiving laser radiation energy can be made in the form of a grid.

The photoelectric converter can be made on the basis of a silicon HJT structure with two-sided sensitivity.

The photovoltaic converter must have a significant external quantum yield at the wavelength of the laser radiation that transmits energy, and have a relatively large area to collect the maximum amount of laser radiation, which has the peculiarity to diverge at a considerable distance from the source, as well as to ensure efficient convective cooling and discharge of excess heat, released in the photovoltaic converter when absorbing radiation that has not been converted into electricity, which should prevent a decrease in the efficiency of photovoltaic conversion due to parasitic heating. The plane of the photoelectric converter can form a small angle with a plane perpendicular to the axis of the information beam, the value of which depends on the divergence of the information radiation and the distance between the communication nodes, ensuring that there is no specular reflection of the information beam in the direction of its emitter. The photovoltaic converter can be made, for example, based on a silicon HJT structure used for mass production of solar cells, with two-sided sensitivity. To ensure the operability of the photoelectric receiving device, the photoelectric converter must have a design that provides transmission of a significant fraction of information radiation, for example, have a rear electrode in the form of a light-transmitting contact grid, and its materials must not have significant absorption in the spectral range of information radiation. The wavelengths of energy and information radiation must correspond to the spectral "windows" of atmospheric transparency in the case of organizing an atmospheric communication line and can satisfy the requirement of invisibility for the human eye. In this case, the radiation of the laser transmitting energy must lie in the spectral range in which the radiation will be almost completely absorbed in the photoelectric converter and not affect the performance of the high-speed photodiode. In practical terms, this means that the energy laser radiation wavelength must be shorter than the information radiation wavelength, for example, an energy laser emits at a wavelength of (0.78-1.0) μm, and a high-speed infrared photodiode receives radiation at a wavelength of (1.2-1.55) µm. The photoelectric converter located in front of the high-speed photodiode will protect the photodiode from part of the external parasitic illumination, acting as an additional light filter. Directly above the photosensitive surface of the high-speed photodiode, a light filter can be placed that protects the photodiode from external spurious radiation in the range of optical transparency of the photoelectric converter. An information photodiode should have a small area of the photosensitive surface to reduce its electrical capacitance and increase its speed, and to increase the level of the recorded information signal, a concentrator should be used that collects information radiation from a relatively large area on the photodiode. If a focusing lens and a conical focon with a mirror inner surface are used as a concentrator, the latter provides reflection of a part of the information radiation concentrator scattered or deviated from the optical axis onto the photosensitive surface of a high-speed photodiode located at the top of the focon. Focon can have an inner surface made of black matte material to prevent re-reflecting onto the photosensitive surface of a high-speed photodiode of radiation coming in a direction not parallel to the optical axis of the concentrator, in order to geometrically highlight a narrow solid angle in space, on the axis of which there is a source of optical information radiation and thus reducing the parasitic illumination of the high-speed photodiode by radiation coming from the rest of the space outside the specified solid angle, which is applicable if the level of direct information radiation is sufficient for its reliable reception, and the direction to the source of information radiation can be maintained with sufficient high accuracy. In the event that the aperture of the laser beam transmitting energy near the photoelectric receiving device occupies a large area, and it is required to generate more electrical energy to power a more powerful load, then several photoelectric converters can be used, possibly of different shapes and sizes, placed in the same plane, forming a photodetector panel with a large total area of photosensitive surfaces and the most dense packing of photoelectric converters, the technological gaps between which are filled with a material opaque for energy laser radiation, while the photodetector panel must have a center of symmetry and allow forming groups of photoelectric converters, each of which contains photoelectric converters will be electrically connected in parallel, each group will generate approximately the same photocurrent under the condition of a centrosymmetric distribution of the intensity of the energy about the beam in the plane of the photodetector panel and the coincidence of their centers of symmetry, and the groups must be electrically connected to each other in series. To save semiconductor materials and reduce the cost of a photodetector panel, it is possible to use not dense packing of photoelectric converters in a common plane, but their placement with gaps that are filled with reflectors in the form of pyramids (or their individual faces) with mirror outer surfaces of the faces that reflect the laser radiation incident on them. on the surface of photovoltaic converters, which makes it possible to choose such an arrangement of photovoltaic converters of a standard shape and size, in which the currents photogenerated in each of them will be close in their values, which will simplify switching between them and increase the overall efficiency of the photodetector panel. If in this case the aperture of the information beam also has a large area near the photoelectric receiving device, and it is necessary to increase the sensitivity of the photoelectric receiving device to information signals, then behind the photodetector panel, close to it, an array of concentrators with fast photodiodes can be placed, forming an axisymmetric figure, the axis of which is perpendicular to the plane photodetector panel and passes through its center of symmetry. In this case, the light-collecting surface of the array of concentrators does not protrude beyond the edges of the photosensitive surface of the photodetector panel. High-speed photodiodes are recommended to be connected with external bias and electrically connected in parallel, while the electronic unit must be optimized for processing current pulses.

This technical solution is illustrated by drawings, where:

figure 1 shows the structure of the photoelectric receiving device of the optical communication line in the form of a block diagram;

FIG. 2 is an enlarged view of the area A of the focusing lens and photoelectric converter shown in FIG. 1. FIG.

This photoelectric receiver of the optical communication line (see figure 1) includes, for example, three flat with a relatively large area photoelectric converter 1 of powerful laser radiation with bilateral sensitivity, each of which is enclosed (see figure 2) between a protective transparent polymer laminating film 2 and clarified glass 3, which protects the photoelectric converter 1 from bending. On the surface of the clarified glass 3, opposite from the photoelectric converter 1, a focusing lens 4, such as a Fresnel lens or a plano-convex lens, is formed. The focusing lens 4 is made, for example, of transparent silicone, and focuses the information radiation passed through the photoelectric converter 1 on a high-speed photodiode 5, protected from stray light by a light filter b. Rigid frame 7 connects into a single structure clarified glass 3 with a photoelectric converter 1 located on it, a protective transparent polymeric laminating film 2 and a focusing lens 4 with a high-speed photodiode Bis-conical focon 7, for example, with a mirror inner surface. Focon 7 (see figure 1) occupies the gap between the focusing lens 4 and high-speed photodiode 5, forming together with the focusing lens 4 concentrator 8 information radiation. High-speed photodiodes 5 are connected in parallel to the first switching board (KP1) 9, the output of which is connected to the input of the electronic unit 10 for processing information signals, containing a series-connected amplifier (A) 11, an RF converter (HFC) 12 with a comparator and a Schmidt trigger (on not shown in the drawing) and a decoder (D) 13, the output of which is intended for connection to the input of active equipment (OUS) 14 of an autonomous communication node. Photoelectric converters 1 for receiving laser radiation energy are equipped with electrodes 15 for removing electricity, installed in front of the concentrators 8 of information radiation and connected by electrodes 15 to the second switching board (KP2) 16, the output of which is connected to the input of the device 17 for converting and accumulating electricity, including series-connected DC -converter-stabilizer (DSP) 18 DC voltage, charge regulator (RC) 19 and energy storage device (NE) 20 (for example, in the form of a battery or ionistor), connected to the power supply circuit of the electronic unit 10 and to the power supply circuit of the OUS 14.

The present photoelectric optical link receiver operates as follows.

On one of the communication nodes via an open optical channel, for example, a laser communication, acting as a subscriber access station, two optical beams are formed, one of which is a powerful laser with continuous or quasi-continuous, for example, invisible to the human eye, radiation with a wavelength for example, (0.78-1.0) µm, intended for power transmission, another - high-frequency modulated, for example, laser, with a wavelength, for example, (1.2-1.55) µm, intended for data transmission. The radiation pattern of each of the beams is formed by its own collimator, which provides a given, as a rule, minimum divergence and an intensity distribution in the beam aperture that is close to uniform (with a "flat" top). The output collimators are located next to each other, and the output beams are directed to one point at a remote autonomous communication node. Taking into account the significant distances of transmission along laser communication lines, two beams can be considered parallel, their apertures at a remote autonomous communication node - coinciding. A real photoelectric receiving device is placed on an autonomous communication node. The center of the photodetector panel is aligned with the center of the beam aperture. The shorter-wavelength high-power laser radiation that has passed through the protective polymer laminating film 2 and entered the silicon HJT structure of the photoelectric converters 1 of the photodetector panel is completely absorbed in this structure, participating in photoelectric conversion. Longer-wavelength information radiation, partially scattered and reflected at the interfaces between the polymer film 3 and the silicon HJT structure of the photoelectric converter 1, the silicon HJT structure and the clarified glass 3, the clarified glass 3 and the silicone of the focusing lens 4 (for example, Fresnel lenses), silicone focusing lens 4 and air, passes through polymer film 2, photoelectric converter 1 (practically not absorbed in it), clarified glass 3 and silicone of focusing lens 4 and then is focused by focusing lenses 4 on the photosensitive surfaces of the array of high-speed photodiodes 5. Part of the information radiation that has passed through the focusing Fresnel lens 4, but scattered on its faces, or when falling on the focusing lens 4, which had a direction different from normal to the plane of the focusing lens 4 so that it is focused outside the photosensitive surface of the fast photodiode 5, falls on the mirror outer the morning surface of the focon 7 and is largely re-reflected on the surface of the photodiode 5. Also, the focon 7 protects the high-speed photodiode 5 from parasitic external side illumination. Part of the information radiation that has reached the photosensitive surface of the high-speed photodiode 5 is converted in it into a photocurrent. High-speed photodiodes 5 are preferably included with external bias to increase performance. High-speed photodiodes 5 of the photodiode array are connected to KP1 9, in which they are electrically connected in parallel to add their photocurrents. The total photocurrent is fed to the U 11 of the electronic unit 10 for processing information signals, then the amplified signal is fed to the VChP 12, in which the comparator cuts off pulses with an amplitude less than a predetermined value, which significantly improves the signal-to-noise ratio, and the missed pulses with sufficient amplitude are fed to Schmidt trigger, at the output of which pulses of a given shape, amplitude and duration are formed. Next, the generated "standardized" pulses enter D 13, which generates an information data stream in accordance with the protocol accepted by the active equipment of the OUS 14. The power supply of the active equipment of the OUS 14, as well as the electronic components of the electronic unit 10, is carried out due to the laser radiation energy absorbed and 1 photodetector panel converted by photoelectric converters. Photoelectric converters 1 of one group inside the photodetector panel using bypass diodes are electrically connected in parallel. Groups are formed based on the centrally symmetrical arrangement of photoelectric converters 1 in such a way that each group generates approximately the same photocurrent. This approach is especially relevant in the case of a centrosymmetric, but not uniform intensity distribution in the energy beam aperture, for example, a Gaussian distribution. The outputs of each group of photoelectric converters 1 are connected to KP2 16, in which the groups are electrically connected to each other in series. KP2 16 is connected to the EAF 18, which supplies "standardized" power to the RH 19, which provides recharging of the NO 20, which, in turn, provides a continuous noise-immune power supply to the active equipment of the OUS 14, as well as electronic components and devices of the electronic unit 10.

Claims (10)

1. A photoelectric receiver of an optical communication line, including at least one information radiation concentrator, in the focus of which a photodiode is installed connected to an electronic information signal processing unit, the output of which is intended for connection to the input of the active equipment of an autonomous communication node, at least one photoelectric a converter for receiving radiation energy, equipped with electrodes for removing electricity and connected by electrodes to an energy storage device, characterized in that a photoelectric converter designed to receive high-power laser radiation is installed in front of an information radiation concentrator with a fast photodiode made in the form of an infrared photodiode, an electronic processing unit information signals includes a series-connected amplifier, a comparator, a Schmidt trigger and a decoder; series-connected DC converters are installed in front of the energy storage device. DC voltage stabilizer and charge controller for the energy storage device. 2. The receiving device according to claim 1, characterized in that the concentrator is made in the form of a focusing parabolic mirror. 3. The receiving device according to claim 1, characterized in that the concentrator is made in the form of a conical focon with a focusing lens placed in the plane of the wide edge of the focon and inscribed in its aperture. 4. The receiving device according to claim. 3, characterized in that the focusing lens is made in the form of a Fresnel lens. 5. The receiving device according to claim 3, characterized in that the focusing lens is made in the form of a plano-convex lens. 6. The receiving device according to claim. 3, characterized in that the faucon is made with a mirror inner surface. 7. The receiving device according to claim 3, characterized in that the faucon is made with a blackened matte inner surface. 8. The receiving device according to claim 1, characterized in that a light filter is installed in front of the high-speed photodiode. 9. The receiving device according to claim 1, characterized in that the high-speed photodiode is made on the basis of an avalanche or pin structure based on Ge, or based on InGaAs semiconductor structures with a spectral absorption band in the infrared region. 10. The receiving device according to claim 1, characterized in that the photoelectric converter for receiving laser radiation energy is made on the basis of a silicon HJT structure with two-sided sensitivity, in which both electrodes on opposite surfaces of the photoelectric converter are made in the form of a contact grid.

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