Self adaptation regulates the optical fiber telecommunications system of received optical power
Technical field
The utility model relates to electronic communication field, is specifically related to the optical fiber telecommunications system that a kind of self adaptation regulates received optical power.
Background technology
Current, along with the data volume of communication system is increasing, signal bandwidth is more and more wider, analog signal optical fiber communication, the especially optical fiber communication of high-frequency analog signal are widely used.Existing analog optical fiber communication technology is comprised of optical sender, optical cable, optical receiver, and because transmission range is different, cable length is different, the loss of transmitting procedure is different, so the luminous power receiving in receiver is different.The optimum reception luminous power of current most of optical receiver is 2 ± 0.5dBm, and high-frequency optical receiver, such as the optical receiver optimum reception luminous power of 20GHz, 50GHz is greater than 2 ± 0.5dBm.The optimum reception luminous power that the luminous power receiving when optical receiver is greater than optical receiver can cause the saturated of receiver, causes signal of telecommunication distortion, non-linear increase, and optical receiver works long hours and in saturation condition, can reduce the useful life of device.The optimum reception luminous power that the luminous power receiving when optical receiver is less than optical receiver can cause that system gain reduces, signal amplitude declines, signal to noise ratio is deteriorated.Visible, whether the optical power value that optical receiver receives is equivalent to its optimum reception luminous power, is related to the quality of analog signal transmission in whole optical fiber telecommunications system.Just because of this reason, existing analog signal optical fiber telecommunications system is only suitable for being operated in the occasion of the specific cable length (transmission range) of system, has limited greatly the application of analog signal optical fiber telecommunications system.On the other hand, in the situation that some fused fiber splice of transmission cable, optical interface connect, thereby also can cause the received optical power of optical receiver too small because of the optical power loss that artificial origin strengthens optic path, impact receives the quality of signal.
Utility model content
The purpose of this utility model is to provide the optical fiber telecommunications system that a kind of self adaptation regulates received optical power, the Output optical power of the analog laser of its optical sender be greater than the higher limit of optimum reception power bracket of optical receiver and transmission attenuation and, in optical receiver, increase a controlled optical attenuator and detect control circuit, the light that enters optical receiver is introduced into optical attenuator and enters optical receiver again, the operating voltage access control testing circuit of the photo-detector in optical receiver, the output of controlling testing circuit accesses the control end of optical attenuator.Photo-detector in optical receiver is voltage signal access control testing circuit by received optical power size conversion, controlling testing circuit detects reception light intensity and is worth the attenuation of regulating and controlling optical attenuator according to this, through optical attenuator, regulate the laggard light power stabilising that enters optical receiver in the optimum reception luminous power of optical receiver, guarantee the quality of optical fiber communication.
The self adaptation of the utility model design regulates the optical fiber telecommunications system of received optical power, comprise optical sender and optical receiver, optical sender is connected by optical cable with optical receiver, the analog optical signal power of analog laser in described optical sender output be greater than optical receiver optimum reception power bracket higher limit and transmission attenuation with, in described optical receiver, be connected to optical attenuator and detect control circuit, analog optical signal is introduced into optical attenuator, enter again optical receiver, the voltage access control testing circuit of the sample resistance that photo-detector connects in optical receiver, control the control end of the output access optical attenuator of testing circuit.
Described control testing circuit comprises single-chip microcomputer and analog-to-digital conversion module, D/A converter module, the voltage signal access analog-to-digital conversion module of described photo-detector, access single-chip microcomputer, the control signal of single-chip microcomputer is digital signal again, is converted to analog signal sends into optical attenuator again through D/A converter module.
Can integrated analog-to-digital conversion module and D/A converter module in described single-chip microcomputer.
Described optical attenuator is the adjustable optical attenuator that attenuation minimum resolution is less than 0.1dB.
Described single-chip microcomputer is furnished with RS-232 interface, through this interface, is connected with host computer, and host computer arranges the received optical power value that Single-chip Controlling regulates, to be suitable for different optical receivers.
When the self adaptation of the utility model design regulates the operation of optical fiber telecommunications system of received optical power, the analog optical signal power of optical sender output be greater than optical receiver optimum reception power bracket higher limit and transmission attenuation with, after optical cable transmission, arrive receiving terminal, through optical attenuator, enter optical receiver; The operating current of the photo-detector in optical receiver is directly proportional to received optical power, and sample resistance transfers the variation of this operating current to detection magnitude of voltage, detects voltage and sends into analog-to-digital conversion module, and the analog information that detects voltage is converted to digital signal; Detect voltage digital signal and send into single-chip microcomputer; Single-chip microcomputer judges the received optical power of current optical receiver according to the detection voltage digital signal of current reception, optimum reception luminous power comparison with stored optical receiver, if current received optical power, in the optimum reception reference optical power of stored optical receiver, proceeds to receive the power detection of light; Otherwise single-chip microcomputer is determined the attenuation of optical attenuator according to the difference of the two, the digital signal of controlling attenuation is sent into D/A converter module, convert a continuous analog voltage signal to, output to optical attenuator; Optical attenuator regulates light decrement under the control of single-chip microcomputer, and the reception light after decay is sent into optical receiver, proceeds to receive the power detection of light.
In native system running, current received optical power is detected to judgement, dynamic adjustments, the received optical power of optical receiver is remained in optimum reception reference optical power.
Compared with prior art, the utility model self adaptation regulates the advantage of the optical fiber telecommunications system of received optical power to be: 1, adopt negative-feedback principle, optical receiver and the optical attenuator connecing, control testing circuit and form a feedback loop, automatically adapt to and regulate received optical power to be stabilized in optimum reception luminous power state, in be accurately controlled at ± 0.5dBm of fluctuation range, efficiently solve the quality problems of the analog signal optical fiber communication causing because optical receiver received optical power is uncontrollable, also exempted preferably the excessive or too small harmful effect that system device is caused of the luminous power receiving because of receiver, 2, the Optical Fiber Transmission between native system optical sender and optical receiver distance is zero when changing in the scope of tens kilometers, and native system all can self adaptation regulates the power of optical receiver, has greatly expanded the application of analog signal optical fiber telecommunications system, the optimum reception luminous power that 3, optical receiver can be set by the RS-232 interface of single-chip microcomputer, is suitable for different optical receivers, 4, all devices are conventional device, so native system is easy to implement, and cost is not high yet, is easy to apply.
Accompanying drawing explanation
Fig. 1 is the optical fiber telecommunications system example structure block diagram of this self adaptation adjusting received optical power.
Embodiment
The optical fiber telecommunications system embodiment of self adaptation adjusting received optical power as shown in Figure 1, comprise optical sender and optical receiver, optical sender is connected by optical cable with optical receiver, the Output optical power of the analog laser in this routine optical sender is 18dBm, operation wavelength is 1550nm, and the optimum reception luminous power of described optical receiver is 1.5dBm~2.5dBm.This routine transmission cable is random length in 0 to tens kilometer range, and native system all can self adaptation regulate the optimum reception luminous power that received optical power is its optical receiver, guarantees the good quality of optical fiber communication.
In optical receiver, be connected to optical attenuator and detect control circuit, analog optical signal is introduced into optical attenuator, enter again optical receiver, the voltage access control testing circuit of the sample resistance that connects of the photo-detector in optical receiver, the output of controlling testing circuit accesses the control end of optical attenuator.In figure, pecked line represents light path, fine line indication circuit.
Described control testing circuit comprises single-chip microcomputer and analog-to-digital conversion module, D/A converter module, the voltage signal access analog-to-digital conversion module of described photo-detector, access single-chip microcomputer, the control signal of single-chip microcomputer is digital signal again, is converted to analog signal sends into optical attenuator again through D/A converter module.
This routine optical attenuator is adjustable optical attenuator, and its attenuation minimum resolution is less than 0.1dB.
Described single-chip microcomputer is furnished with RS-232 interface, is connected with host computer, and host computer arranges the received optical power value that Single-chip Controlling regulates, to be suitable for different optical receivers.
Above-described embodiment, is only the specific case that the purpose of this utility model, technical scheme and beneficial effect are further described, and the utility model is not defined in this.All any modifications of making, be equal to replacement, improvement etc., within being all included in protection range of the present utility model within scope of disclosure of the present utility model.