Optical receiving assembly for signal detection and optical power monitoring

Abstract

The utility model relates to the technical field of microwave photon communication, and discloses an optical receiving assembly used for signal detection and optical power monitoring, the optical receiving assembly comprises a housing and an optical receiving assembly arranged in the housing, the optical receiving assembly comprises an optical path unit used for refracting incident light and then transmitting the refracted incident light, the optical path unit comprises an inclined plane optical fiber, and the inclined plane optical fiber is used for transmitting the refracted incident light. A receiving part is arranged at one end of the inclined plane optical fiber, an emitting part is arranged at the other end of the inclined plane optical fiber, and a reflecting inclined plane is arranged on the emitting part; the photoelectric conversion unit is used for converting an optical signal into an electric signal, and the photoelectric conversion unit comprises a detector directly coupled with the output end of the optical path unit; the microwave unit is connected with the photoelectric conversion unit and used for amplifying and outputting the converted current signal, and the microwave unit comprises an amplifier; and the monitoring unit is connected with the photoelectric conversion unit and is used for monitoring the optical power.

Description

Technical Field

[0001] The utility model relates to the technical field of microwave photon communications, in particular to an optical receiving component used for signal detection and optical power monitoring. Background Art

[0002] In the microwave photonic RF transmission system link, in order to achieve optical signal monitoring, optoelectronic conversion and signal amplification, after the optical receiver receives the photon signal, it converts the optical signal into an electrical signal through optoelectronic conversion; the converted electrical signal is transmitted throughout the link through a cable connection; but the converted electrical signal is generally relatively weak, and there will be losses during cable transmission, so the received electrical signal will be amplified to ensure complete signal transmission; usually an amplifier is added to the back end of the receiving component to amplify the signal; at the same time, when the optical receiver receives the optical signal, if the input optical power needs to be monitored in the link, an optical splitter must be added on the optical input side of the optoelectronic receiving component to perform real-time monitoring of the optical power and confirm the strength of the signal input, thereby achieving the monitoring effect of the link.

[0003] The above system is implemented by constructing discrete components such as amplifiers, optical receiving components, optical splitters, and control circuit components, and realizes electrical connection and signal transmission through optical fibers, radio frequency cables, wires, etc. The packaging of such systems is large in size and heavy in weight, and cannot meet the trend of miniaturization and integration. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the deficiencies of the existing technology, provide an optical receiving component for signal detection and optical power monitoring, reduce the loss of signal light in link transmission, improve the transmission rate and transmission quality, and realize real-time monitoring of optical power.

[0005] The technical solution of the utility model is as follows: comprising a housing and a light receiving assembly arranged in the housing, the light receiving assembly comprising:

[0006] An optical path unit, the optical path unit comprising an inclined optical fiber, wherein one end of the inclined optical fiber is provided with a receiving portion and the other end is provided with an emitting portion, the emitting portion is provided with a reflective inclined surface, and light is totally reflected on the reflective inclined surface;

[0007] a photoelectric conversion unit, configured to convert the optical signal into a current signal, the photoelectric conversion unit comprising a detector directly coupled to the output end of the optical path unit;

[0008] a microwave unit connected to the photoelectric conversion unit, configured to amplify the converted current signal and output it, the microwave unit comprising an amplifier;

[0009] A monitoring unit is connected to the photoelectric conversion unit and is used to monitor the optical power through a current signal. The monitoring unit includes a resistor and an operational amplifier connected to the resistor.

[0010] It can be seen from the above scheme that the beveled optical fiber reflects the optical signal input from the receiving end to the detection chip through the reflective bevel of the output part. The microwave unit is used to input the radio frequency signal into the low-noise amplifier through the radio frequency microstrip after receiving the radio frequency signal. The low-noise amplifier is used to amplify the received current signal and reduce the noise introduced by the amplifier as much as possible. The attenuator is used to buffer the impedance transformation and improve the impedance matching. The monitoring unit is used to connect the passing current signal to the operational amplifier through a resistor in series. After the operational amplifier amplifies the signal, it outputs the corresponding voltage value, thereby realizing the monitoring of optical power. The utility model realizes the hybrid integration of spatial optical path, radio frequency link and control circuit in the shell, realizes airtight packaging, reduces the loss of optical signal transmission in the cable, improves the transmission rate, has good channel isolation, low power consumption, and greatly improves the integration of the system. The utility model fully chips the low-noise amplifier and attenuator parts in the radio frequency link and integrates them into a cavity, thereby improving the system integration, reducing the volume and saving space.

[0011] A photosensitive surface is provided on one side of the detector, and the photosensitive surface is correspondingly provided below the emission portion. Thus, the detector receives the light signal reflected by the reflective inclined surface through the photosensitive surface and converts the received light signal into a current signal.

[0012] The attenuator output end is connected to a radio frequency cable, and a radio frequency coaxial connector is provided between the attenuator and the radio frequency cable. It can be seen that the radio frequency coaxial connector is used to connect the attenuator and the radio frequency cable, and the radio frequency coaxial connector is used to transmit analog signals and reduce radio frequency signal loss.

[0013] The optical receiving component further includes a control circuit, which is connected to the photoelectric conversion unit, the microwave unit and the monitoring unit respectively.

[0014] The resistor is an adjustable resistor, and the resistance value of the resistor corresponds to the amplification factor of the operational amplifier. Therefore, the amplification factor of the operational amplifier can be adjusted by adjusting the resistance value of the resistor. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of the utility model;

[0016] Figure 2 It is a structural diagram of the utility model;

[0017] Figure 3 It is a connection diagram of the utility model;

[0018] Figure 4 It is a schematic diagram of light transmission mode in an inclined optical fiber;

[0019] Figure 5 This is the circuit schematic diagram of the detector;

[0020] Figure 6 It is a partial connection diagram of the utility model. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0022] like Figures 1 to 6 As shown, the present invention provides an optical receiving assembly for signal detection and optical power monitoring, including a housing 100 and an optical receiving assembly disposed in the housing 100, the optical receiving assembly including:

[0023] An optical path unit 1, comprising an inclined optical fiber 11, wherein one end of the inclined optical fiber 11 is provided with a receiving portion and the other end is provided with an emitting portion, wherein the emitting portion is provided with a reflective inclined surface 12, and light is totally reflected on the reflective inclined surface 12;

[0024] A photoelectric conversion unit 2, configured to convert the optical signal into a current signal, wherein the photoelectric conversion unit 2 comprises a detector 21 directly coupled to the output end of the optical path unit 1;

[0025] A microwave unit 3 connected to the photoelectric conversion unit 2, configured to amplify the converted current signal and output it, the microwave unit 3 including an amplifier 31;

[0026] The monitoring unit 4 is connected to the photoelectric conversion unit 2 and is used to monitor the optical power through the current signal. The monitoring unit 4 includes a resistor 41 and an operational amplifier 42 connected to the resistor 41 .

[0027] In this embodiment, the housing 100 is made of a volatile alloy, which has excellent airtightness and signal shielding. The beveled optical fiber 11 is fixed by welding or gluing. Chips, resistors and capacitors, and circuit boards are all bonded to the housing 100 using conductive glue. A cover plate 200 is provided on the housing 100, and a storage space adapted to the light receiving component is provided inside the housing 100. The housing 100 and the cover plate 200 are sealed in parallel, and an airtightness test is required after the packaging is completed. The beveled optical fiber 11 adopts a direct coupling method to couple the input optical signal to the photosensitive surface of the detector 21 of the photoelectric conversion unit 2 through the reflective bevel 12, and then the beveled optical fiber 11 and the detector 21 are fixed inside the housing 100 by resistance welding or laser welding.

[0028] A photosensitive surface is provided on one side of the detector 21, and the photosensitive surface is correspondingly arranged below the emission portion. In this embodiment, the detector 21 is a detector chip, the photoelectric conversion unit also includes a matching circuit, the beveled optical fiber 11 is arranged horizontally within the housing, and the detector 21 is correspondingly arranged below the reflective bevel 12. The light signal is totally reflected by the reflective bevel 12, and the reflected light signal is output to the photoelectric conversion unit 2. The detector 21 is used to receive the light signal through the photosensitive surface and convert it into a current signal.

[0029] The amplifier 31 is a low noise amplifier. The output end of the amplifier 31 is connected to an attenuator 32 . The output end of the attenuator 32 is connected to a radio frequency cable. A radio frequency coaxial connector is provided between the attenuator 32 and the radio frequency cable.

[0030] The resistor 41 is an adjustable resistor, and the resistance value of the resistor 41 corresponds to the amplification factor of the operational amplifier 42. In this embodiment, the amplification factor of the operational amplifier 42 is adjusted by adjusting the resistance value of the resistor 41.

[0031] The optical receiving component further includes a control circuit 5 , which is connected to the photoelectric conversion unit 2 , the microwave unit 3 , and the monitoring unit 4 respectively.

[0032] In this embodiment, the transmission angle α of light in the receiving part satisfies the following formula:

[0033] α=90°-sin -1 (n2 / n1);

[0034] The angle β between the reflecting slope 12 and the horizontal plane satisfies the following formula:

[0035] β=90°-α-sin -1 (1 / n1);

[0036] Wherein, α is the light transmission angle, β is the fiber bevel angle, n1 is the fiber core refractive index, n2 is the fiber cladding refractive index, and n1>n2.

[0037] When the bevel optical fiber 11 used is a single-mode optical fiber, the angles α and β can be calculated by referring to the n1 and n2 parameters of the single-mode optical fiber. The angle β between the reflecting bevel 12 and the horizontal plane can be set in the range of 41° to 44°.

[0038] The working process of the present invention is as follows: when light is input, the light is horizontally incident in the oblique optical fiber 11, and the light is emitted to the detector 21 after being totally reflected at the reflecting inclined surface 12. The photosensitive surface of the detector 21 receives the light signal, and converts the light signal into a current signal through photoelectric conversion and outputs it. The microwave unit 3 amplifies the current signal through the low-noise amplifier 31, while minimizing the noise introduced after the signal amplification. The amplified electrical signal is buffered and impedance transformed through the attenuator 32 to improve impedance matching. At the same time, the monitoring unit 4 amplifies the current signal passing through the resistor 41 through the operational amplifier 42 and outputs the corresponding voltage value, thereby realizing the monitoring of the optical power.

[0039] Finally, it should be emphasized that the above description is not intended to limit the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An optical receiving assembly for signal detection and optical power monitoring, comprising a housing (100) and an optical receiving assembly disposed in the housing (100), characterized in that: The light receiving component includes: An optical path unit (1), the optical path unit (1) comprising an inclined optical fiber (11), one end of the inclined optical fiber (11) being provided with a receiving portion, the other end being provided with an emitting portion, the emitting portion being provided with a reflecting inclined surface (12), and light being totally reflected on the reflecting inclined surface (12); A photoelectric conversion unit (2) is used to convert the optical signal into a current signal, the photoelectric conversion unit (2) comprising a detector (21) directly coupled to the output end of the optical path unit (1); A microwave unit (3) is connected to the photoelectric conversion unit (2) and is used to amplify the converted current signal and output it. The microwave unit (3) includes an amplifier (31); A monitoring unit (4) is connected to the photoelectric conversion unit (2) and is used to monitor the optical power through a current signal. The monitoring unit (4) includes a resistor (41) and an operational amplifier (42) connected to the resistor (41).

2. The optical receiving component for signal detection and optical power monitoring according to claim 1, characterized in that: A photosensitive surface is provided on one side of the detector (21), and the photosensitive surface is correspondingly provided below the emission portion.

3. The optical receiving component for signal detection and optical power monitoring according to claim 2, characterized in that: The amplifier (31) is a low-noise amplifier, and the output end of the amplifier (31) is connected to an attenuator (32).

4. The optical receiving component for signal detection and optical power monitoring according to claim 3, characterized in that: The output end of the attenuator (32) is connected to a radio frequency cable, and a radio frequency coaxial connector is provided between the attenuator (32) and the radio frequency cable.

5. The optical receiving component for signal detection and optical power monitoring according to claim 4, characterized in that: The light receiving component further comprises a control circuit (5), and the control circuit (5) is respectively connected to the photoelectric conversion unit (2), the microwave unit (3), and the monitoring unit (4).

6. The optical receiving component for signal detection and optical power monitoring according to claim 5, characterized in that: The resistor (41) is an adjustable resistor, and the resistance value of the resistor (41) corresponds one-to-one to the amplification factor of the operational amplifier (42).

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