A driving circuit and driving system of an optical filter

Abstract

The present invention relates to the field of optical filter driving technology, and specifically to a driving circuit of an optical filter, including a low-voltage digital-to-analog conversion circuit module, which is used to convert an external control signal into a first analog signal; a differential circuit module, which is connected to the low-voltage digital-to-analog conversion circuit module to receive the first analog signal and output a second analog signal and a third analog signal after differential conversion; a first driving circuit module, which is connected to the differential circuit module to receive the second analog signal and amplify and output it to the first control end of the optical filter; and a second driving circuit module, which is connected to the differential circuit module to receive the third analog signal and amplify and output it to the second control end of the optical filter. The present invention also relates to a driving system for an optical filter. A differential circuit module is provided to convert a control signal into two signals to drive the optical filter to work, so that the optical filter can be driven by one control pin, and the circuit structure is simple, the application is simple, and the circuit and software control costs are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of optical filter driving, and in particular to a driving circuit and a driving system for an optical filter. Background Art

[0002] Fiber amplifiers are optical amplifiers used in fiber optic communication systems to directly amplify optical signals. In communication systems using optical fibers, a technology that directly amplifies optical signals without converting them into electrical signals is used. Erbium-doped fiber amplifiers are a type of fiber amplifier. Erbium-doped fiber amplifiers use optical filters to filter out stray light. The optical filter has three pins, two of which are drive pins that require high voltage drive, and the other is a ground pin.

[0003] In the existing optical filter driving circuit, two control pins are used to provide driving voltage to the two driving pins of the optical filter to control the operation of the optical filter and the output wavelength of the optical filter. If one control pin is used to control the two driving pins of the optical filter, the circuit control cost is high, the software control cost is high, and the application is complex. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a driving circuit and a driving system for an optical filter in view of the above-mentioned defects of the prior art, so as to overcome the problems of high circuit control cost, high software control cost and complex application of the prior art which uses one control pin to realize the driving control of the optical filter.

[0005] The technical solution adopted by the present invention to solve the technical problem is: to provide a driving circuit of an optical filter, the optical filter comprising a first control end and a second control end for controlling the filtering wavelength, the driving circuit comprising:

[0006] A low-voltage digital-to-analog conversion circuit module, used for converting a digital signal into a first analog signal;

[0007] A differential circuit module is connected to the low-voltage digital-to-analog conversion circuit module to receive the first analog signal and output a second analog signal and a third analog signal after performing differential conversion;

[0008] A first driving circuit module is connected to an output end of the differential circuit module to receive the second analog signal and amplify the second analog signal before outputting it to the first control end of the optical filter;

[0009] The second driving circuit module is connected to the other output end of the differential circuit module to receive the third analog signal and amplify the third analog signal before outputting it to the second control end of the optical filter.

[0010] A further preferred embodiment of the present invention is that the differential circuit module includes a follower unit connected to the low voltage digital-to-analog conversion circuit module and the first driving circuit module respectively, and a subtractor unit connected to the low voltage digital-to-analog conversion circuit module and the second driving circuit module respectively.

[0011] A further preferred solution of the present invention is that the follower unit comprises a first operational amplifier connected to the low voltage digital-to-analog conversion circuit module and the first driving circuit module respectively.

[0012] A further preferred solution of the present invention is that the subtractor unit includes a second operational amplifier connected to the low-voltage digital-to-analog conversion circuit module and the second driving circuit module respectively.

[0013] A further preferred solution of the present invention is that both the first driving circuit module and the second driving circuit module include a high-voltage amplifier unit.

[0014] A further preferred solution of the present invention is that the high-voltage amplifier unit includes a third operational amplifier connected to the differential circuit module and the optical filter respectively.

[0015] A further preferred embodiment of the present invention is that the optical filter comprises a tunable optical filter.

[0016] The technical solution adopted by the present invention to solve its technical problem is: to provide a driving system for an optical filter, including the driving circuit, a control unit whose output end is connected to the driving circuit and outputs a control signal to the driving circuit, and an optical filter connected to the driving circuit, wherein the driving circuit receives the control signal of the control unit and converts it into a second analog signal and a third analog signal, then outputs the second analog signal to the first control end of the optical filter, and outputs the third analog signal to the second control end of the optical filter.

[0017] The beneficial effect of the present invention is that, compared with the prior art, a differential circuit module is set to perform differential transformation on the first analog signal converted by the low-voltage digital-to-analog conversion circuit module, and then output a second analog signal and a third analog signal, which are respectively amplified by the first drive circuit module and the second drive circuit module and then output to the first control end and the second control end of the optical filter, respectively, so that the operation of the optical filter can be controlled by one control pin, the circuit structure is simple, the application is simple, and the circuit control cost and the software control cost are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0019] Figure 1 It is a brief principle block diagram of the driving circuit of the optical filter of the present invention;

[0020] Figure 2 It is a specific principle block diagram of the driving circuit of the optical filter of the present invention;

[0021] Figure 3 is a structural block diagram of a differential circuit module of the present invention;

[0022] Figure 4 is a circuit diagram of a follower unit of the present invention;

[0023] Figure 5 is a circuit diagram of a subtractor unit of the present invention;

[0024] Figure 6 is a circuit diagram of a first high-voltage amplifier unit of the present invention. DETAILED DESCRIPTION

[0025] Now, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0026] like Figure 1 and Figure 2 As shown, the present invention provides a preferred embodiment of a driving circuit for an optical filter.

[0027] The optical filter comprises a first control terminal and a second control terminal for controlling a filtering wavelength, and a driving circuit of the optical filter comprises:

[0028] The low-voltage digital-to-analog conversion circuit module 10 is used to convert an external input control signal into a first analog signal;

[0029] The differential circuit module 20 is connected to the low voltage digital-to-analog conversion circuit module 10 to receive the first analog signal and output the second analog signal and the third analog signal after performing differential conversion;

[0030] The first driving circuit module 30 is connected to an output end of the differential circuit module 20 to receive the second analog signal and amplify the second analog signal before outputting it to the first control end of the optical filter;

[0031] The second driving circuit module 40 is connected to the other output end of the differential circuit module 20 to receive the third analog signal and amplify the third analog signal before outputting it to the second control end of the optical filter.

[0032] By setting a differential circuit module 20, the first analog signal converted by the low-voltage digital-to-analog conversion circuit module 10 is differentially transformed to output a second analog signal and a third analog signal, which are respectively amplified by the first drive circuit module 30 and the second drive circuit module 40 and output to the first control end and the second control end of the optical filter, respectively, so that the operation of the optical filter can be controlled by one control pin, the circuit structure is simple, the application is simple, and the circuit control cost and the software control cost are reduced.

[0033] Specifically, the low-voltage digital-to-analog conversion circuit module 10 includes a low-voltage digital-to-analog conversion chip 11. The low-voltage digital-to-analog conversion chip 11 receives an external input control signal, converts the control signal into a first analog signal of 0-2.5V and transmits it to the differential circuit module 20, and the differential circuit module 20 performs differential conversion on the first analog signal and outputs a second analog signal in phase with the first analog signal and a third analog signal in phase with the first analog signal, and the first drive circuit module 30 amplifies the second analog signal, and the second drive circuit module 40 amplifies the third analog signal, and the first drive circuit module 30 and the second drive circuit module 40 simultaneously transmit the amplified signals, that is, the analog signal of 0-40V and the analog signal of 40-0V to the first control end and the second control end of the optical filter, that is, the first drive circuit module 30 transmits the amplified analog signal of 0-40V to the first control end of the optical filter, and the second drive circuit module 40 transmits the amplified analog signal of 40-0V to the second control end of the optical filter, so as to realize the use of one control pin to control the operation of the optical filter.

[0034] Compared with the existing optical filter driving circuit using two low-voltage digital-to-analog conversion chips 11, the driving circuit in the embodiment of the present invention uses one low-voltage digital-to-analog conversion chip 11 to control the two driving pins of the optical filter, thereby reducing costs.

[0035] like Figure 3 As shown, the present invention provides a preferred embodiment of a differential circuit module.

[0036] The differential circuit module 20 includes a follower unit 21 connected to the low voltage digital-to-analog conversion circuit module 10 and the first driving circuit module 30 respectively, and a subtractor unit 22 connected to the low voltage digital-to-analog conversion circuit module 10 and the second driving circuit module 40 respectively.

[0037] In this embodiment, the first analog signal of 0 to 2.5V output by the low-voltage digital-to-analog conversion circuit module 10 is input into the follower unit 21 to realize voltage following, and a second analog signal in phase with the first analog signal is output; the first analog signal of 0 to 2.5V output by the low-voltage digital-to-analog conversion circuit module 10 is input into the subtractor unit 22, and a third analog signal in phase with the first analog signal is output. The second analog signal and the third analog signal are amplified by the first drive circuit module 30 and the second drive circuit module 40 and output to the first control end and the second control end of the optical filter respectively. The voltage sum of the first control end and the second control end of the optical filter is kept constant, thereby realizing the drive control of the optical filter.

[0038] The follower unit 21 includes a first operational amplifier U1 connected to the low voltage digital-to-analog conversion circuit module 10 and the first driving circuit module 30 respectively. Figure 4The non-inverting input terminal of the first operational amplifier U1 is connected to the low-voltage digital-to-analog conversion circuit module 10 , and the inverting input terminal is connected to the output terminal of the first operational amplifier U1 and connected to the first driving circuit module 30 .

[0039] The subtractor unit 22 includes a second operational amplifier U2 connected to the low voltage digital-to-analog conversion circuit module 10 and the second driving circuit module 40 respectively. Figure 5 The subtractor unit 22 further includes a resistor R1, a resistor R2, a resistor R3, and a resistor R4. The non-inverting input terminal of the second operational amplifier U2 is connected to the low-voltage digital-to-analog conversion circuit module 10 through the resistor R1, and is grounded through the resistor R2, and the inverting input terminal is connected to the output terminal of the second operational amplifier U2 through R3 and is connected to the second driving circuit module 40, and the inverting input terminal is grounded through the resistor R4.

[0040] Furthermore, the first driving circuit module 30 and the second driving circuit module 40 both include a high-voltage amplifier unit. Specifically, the first driving circuit module 30 includes a first high-voltage amplifier unit 31 , and the second driving circuit module 40 includes a second high-voltage amplifier unit 41 .

[0041] Further, the high-voltage amplifier unit includes a third operational amplifier connected to the differential circuit module 20 and the optical filter, respectively. The third operational amplifier includes a fourth operational amplifier U3 and a fifth operational amplifier. Specifically, the first high-voltage amplifier unit 31 includes a fourth operational amplifier U3 connected to the follower unit 21 and the first control end of the optical filter, respectively, and the second high-voltage amplifier unit 41 includes a fifth operational amplifier connected to the subtractor unit 22 and the second control end of the optical filter, respectively.

[0042] refer to Figure 6 , the first high-voltage amplifier unit 31 also includes a resistor R5 and a resistor R6. The in-phase input terminal of the fourth operational amplifier U3 is connected to the follower unit 21 to receive the second analog signal, and the inverting input terminal is grounded through the resistor R5, and is connected to the second control terminal of the optical filter through the resistor R6. The structure and working principle of the second high-voltage amplifier unit 32 are the same as those of the first high-voltage amplifier unit 31, and are not described in detail here.

[0043] The first control terminal and the second control terminal of the optical filter need to be driven by a high voltage signal. The signal output by the low voltage digital-to-analog conversion circuit module 10 is a low voltage signal, and the signal after differential conversion by the differential circuit module 20 is also a low voltage signal. The low voltage signal is amplified by the high voltage amplifier unit to drive the optical filter.

[0044] Furthermore, the driving circuit of the optical filter can drive an optical filter with a fixed frequency or an adjustable optical filter. In this embodiment, the optical filter includes an adjustable optical filter.

[0045] The invention also provides a driving system for an optical filter.

[0046] The driving system includes the driving circuit described above, a control unit whose output end is connected to the driving circuit and outputs a control signal to the driving circuit, and an optical filter connected to the driving circuit. After the driving circuit receives the control signal of the control unit and converts it into a second analog signal and a third analog signal, it outputs the second analog signal to the first control end of the optical filter and outputs the third analog signal to the second control end of the optical filter.

[0047] Specifically, the control unit of the driving system is connected to the low-voltage digital-to-analog conversion circuit module 10 of the driving circuit, the first driving circuit module 30 of the driving circuit is connected to the first control end of the optical filter, and the second driving circuit module 40 of the driving circuit is connected to the second control end of the optical filter.

[0048] The driving system performs differential transformation on the first analog signal converted by the low-voltage digital-to-analog conversion circuit module 10 by setting a differential circuit module 20 of the driving circuit, and then outputs a second analog signal and a third analog signal, which are respectively amplified by the first driving circuit module 30 and the second driving circuit module 40 and then output to the first control end and the second control end of the optical filter, respectively, so as to realize the control of driving the optical filter by using one control pin, and has a simple circuit structure and simple application, thereby reducing the circuit control cost and the software control cost.

[0049] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. For those skilled in the art, the technical solutions described in the above embodiments can be modified, or some of the technical features therein can be replaced by equivalents; and all these modifications and replacements should fall within the scope of protection of the claims attached to the present invention.

Claims

1. A driving circuit for an optical filter, the optical filter comprising a first control terminal and a second control terminal for controlling a filtering wavelength, characterized in that: The driving circuit comprises: A low-voltage digital-to-analog conversion circuit module, used for converting an external input control signal into a first analog signal; A differential circuit module is connected to the low-voltage digital-to-analog conversion circuit module to receive the first analog signal and output a second analog signal and a third analog signal after performing differential conversion; A first driving circuit module is connected to an output end of the differential circuit module to receive the second analog signal and amplify the second analog signal before outputting it to the first control end of the optical filter; A second driving circuit module is connected to the other output end of the differential circuit module to receive the third analog signal and amplify the third analog signal before outputting it to the second control end of the optical filter; The low-voltage digital-to-analog conversion circuit module includes a low-voltage digital-to-analog conversion chip, which receives an external control signal, converts the control signal into a first analog signal and transmits it to the differential circuit module.

2. The driving circuit according to claim 1, characterized in that: The differential circuit module includes a follower unit connected to the low voltage digital-to-analog conversion circuit module and the first driving circuit module respectively, and a subtractor unit connected to the low voltage digital-to-analog conversion circuit module and the second driving circuit module respectively.

3. The driving circuit according to claim 2, characterized in that: The follower unit includes a first operational amplifier connected to the low voltage digital-to-analog conversion circuit module and the first driving circuit module respectively.

4. The driving circuit according to claim 3, characterized in that: The subtractor unit includes a second operational amplifier connected to the low voltage digital-to-analog conversion circuit module and the second driving circuit module respectively.

5. The driving circuit according to claim 2, characterized in that: The first driving circuit module and the second driving circuit module both include a high voltage amplifier unit.

6. The driving circuit according to claim 5, characterized in that: The high-voltage amplifier unit includes a third operational amplifier connected to the differential circuit module and the optical filter respectively.

7. The driving circuit according to any one of claims 1 to 6, characterized in that: The optical filter comprises a tunable optical filter.

8. A driving system for an optical filter, characterized in that: The driving system includes a driving circuit as described in any one of claims 1 to 7, an output end connected to the driving circuit and outputting a control signal to a control unit of the driving circuit, and an optical filter connected to the driving circuit, wherein the driving circuit receives the control signal of the control unit and converts it into a second analog signal and a third analog signal, then outputs the second analog signal to the first control end of the optical filter, and outputs the third analog signal to the second control end of the optical filter.

Images