A driving circuit and driving system of an optical filter

Abstract

The present invention relates to the field of optical filter driving, and specifically to a driving circuit and driving system of an optical filter. The driving circuit includes a low-voltage digital-to-analog conversion circuit module, which converts an input control signal into a first analog signal; a follower circuit module, which is connected to the low-voltage digital-to-analog conversion circuit module and outputs a second analog signal; a first subtraction circuit module, whose input end is connected to the follower circuit module and outputs a third analog signal; a second subtraction circuit module, whose input end is connected to the follower circuit module and outputs a fourth analog signal; a first driving circuit module, which is connected to the output end of the first subtraction circuit module to receive the third analog signal and amplify it and output it to the first control end of the optical filter; and a second driving circuit module, which is connected to the output end of the second subtraction circuit module to receive the fourth analog signal and amplify it and output it to the second control end of the optical filter. The present invention saves one control pin while maintaining the original unbalanced control, and has low cost.

Description

Technical Field

[0001] The present invention relates to the field of optical filter driving, and in particular to a driving circuit and a driving system of 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, there are two control pins, and two digital-to-analog conversion chips are required to provide driving voltages 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 an external input control signal into a first analog signal;

[0007] A follower 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 after processing;

[0008] A first subtraction circuit module, whose input end is connected to the follower circuit module to receive the second analog signal and output a third analog signal after processing;

[0009] A second subtraction circuit module, whose input end is connected to the follower circuit module to receive the second analog signal and output a fourth analog signal after processing;

[0010] A first driving circuit module is connected to the output end of the first subtraction circuit module to receive the third analog signal and amplify the third analog signal before outputting it to the first control end of the optical filter;

[0011] The second driving circuit module is connected to the output end of the second subtraction circuit module to receive the fourth analog signal, amplify the fourth analog signal, and then output it to the second control end of the optical filter.

[0012] A further preferred solution of the present invention is that the follower circuit module includes a first operational amplifier whose input end is connected to the low-voltage digital-to-analog conversion circuit module and whose output end is respectively connected to the first subtraction circuit module and the second subtraction circuit module.

[0013] A further preferred solution of the present invention is that the first subtraction circuit module includes a second operational amplifier whose input end is connected to the follower circuit module and whose output end is connected to the first drive circuit module.

[0014] A further preferred solution of the present invention is that the second subtraction circuit module includes a third operational amplifier whose input end is connected to the follower circuit module and whose output end is connected to the second drive circuit module.

[0015] A further preferred solution of the present invention is that the first driving circuit module includes a first high-voltage amplifier unit connected to the first subtraction circuit module and the first control end of the optical filter respectively.

[0016] A further preferred solution of the present invention is that the second driving circuit module includes a second high-voltage amplifier unit connected to the second subtraction circuit module and the second control end of the optical filter respectively.

[0017] A further preferred embodiment of the present invention is that the optical filter comprises a tunable optical filter.

[0018] 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 third analog signal and a fourth analog signal, then outputs the third analog signal to the first control end of the optical filter, and outputs the fourth analog signal to the second control end of the optical filter.

[0019] The beneficial effect of the present invention lies in that, compared with the prior art, by setting a follower circuit module, a first subtraction circuit module and a second subtraction circuit module, a low-voltage digital-to-analog conversion circuit module converts an external input control signal into a first analog signal, and the converted first analog signal is processed by the follower circuit module and the first subtraction circuit module to output a third analog signal, which is then amplified by the first drive circuit module and output to the first control end of the optical filter. At the same time, the first analog signal is processed by the follower circuit module and the second subtraction circuit module to output a fourth analog signal, which is then amplified by the second drive circuit module and output to the second control end of the optical filter, thereby realizing the control of the first control end and the second control end of the optical filter respectively, while maintaining the original unbalanced control, saving a control pin, having a simple circuit structure, simple application, and reducing circuit control cost and software control cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0021] Figure 1 is a block diagram of a driving circuit of an optical filter of the present invention;

[0022] Figure 2 is a structural block diagram of a driving system of an optical filter of the present invention;

[0023] Figure 3 is a specific structural block diagram of the driving system of the optical filter of the present invention;

[0024] Figure 4 It is a circuit diagram of a driving system of an optical filter 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 As shown, the present invention provides a preferred embodiment of a driving circuit for an optical filter.

[0027] A driving circuit of an optical filter, the optical filter 300 comprises a first control terminal and a second control terminal for controlling a filtering wavelength, the driving circuit 100 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 follower circuit module 20 is connected to the low voltage digital-to-analog conversion circuit module 10 to receive the first analog signal and output a second analog signal after processing;

[0030] The first subtraction circuit module 30, whose input end is connected to the follower circuit module 20 to receive the second analog signal and output a third analog signal after processing;

[0031] The second subtraction circuit module 40, whose input end is connected to the follower circuit module 20, receives the second analog signal and outputs a fourth analog signal after processing;

[0032] The first driving circuit module 50 is connected to the output end of the first subtraction circuit module 30 to receive the third analog signal and amplify the third analog signal before outputting it to the first control end of the optical filter 300;

[0033] The second driving circuit module 60 is connected to the output end of the second subtraction circuit module 40 to receive the fourth analog signal, amplify the fourth analog signal, and then output it to the second control end of the optical filter 300 .

[0034] By setting a follower circuit module 20, a first subtraction circuit module 30 and a second subtraction circuit module 40, the low-voltage digital-to-analog conversion circuit module 10 converts an external input control signal into a first analog signal. The converted first analog signal is processed by the follower circuit module 20 and the first subtraction circuit module 30 to output a third analog signal, which is then amplified by the first drive circuit module 50 and output to the first control end of the optical filter 300. At the same time, the first analog signal is processed by the follower circuit module 20 and the second subtraction circuit module 40 to output a fourth analog signal, which is then amplified by the second drive circuit module 60 and output to the second control end of the optical filter 300, thereby respectively controlling the first control end and the second control end of the optical filter 300, while maintaining the original unbalanced control, saving a control pin, having a simple circuit structure, simple application, and reducing circuit control costs and software control costs.

[0035] The third analog signal controlling the first control end of the optical filter 300 and the fourth analog signal controlling the second control end of the optical filter 300 do not affect each other, and the third analog signal and the fourth analog signal independently control the corresponding first control end and the second control end.

[0036] Specifically, the low-voltage digital-to-analog conversion circuit module 10 includes a low-voltage digital-to-analog conversion chip. The low-voltage digital-to-analog conversion chip receives an external input control signal and converts it into a first analog signal, such as converting the control signal into a first analog signal of 0-2.5V and transmitting it to the follower circuit module 20, which is processed by the follower circuit module 20 to output a second analog signal, and is transmitted to the first subtraction circuit module 30 and the second subtraction circuit module 40 respectively, and the first subtraction circuit module 30 processes the second analog signal and outputs a third analog signal to the first drive circuit module 50, and the first drive circuit module 50 amplifies the third analog signal; at the same time, the second subtraction circuit module 40 processes the second analog signal and outputs a fourth analog signal to the second drive circuit module 60, and the second drive circuit module 60 amplifies the fourth analog signal, that is, the analog signal of 0-2.5V is finally amplified by the first drive circuit module 50 and the second drive circuit module 60 to output a 40-0V analog signal and transmit it to the first control end and the second control end of the optical filter 300, so as to realize the use of one control pin to control the operation of the optical filter 300, and at the same time, the analog signals output by the first subtraction circuit module 30 and the second subtraction circuit module 40 do not affect each other.

[0037] Compared with the existing driving circuit 100 of the optical filter 300 using two low-voltage digital-to-analog conversion chips, the driving circuit 100 in the embodiment of the present invention uses one low-voltage digital-to-analog conversion chip to achieve independent control of the two control ends of the optical filter 300, thereby reducing costs and maintaining the unbalanced control of the existing solution.

[0038] In this embodiment, the follower circuit module 20 includes a first operational amplifier U1 whose input end is connected to the low voltage digital-to-analog conversion circuit module 10 and whose output end is respectively connected to the first subtraction circuit module 30 and the second subtraction circuit module 40 .

[0039] Specifically, refer to Figure 4 The 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 subtraction circuit module 30 and the second subtraction circuit module 40. After the first analog signal passes through the first operational amplifier, voltage following is achieved to improve the circuit load capacity.

[0040] In this embodiment, the first subtraction circuit module 30 includes a second operational amplifier U2 whose input end is connected to the follower circuit module 20 and whose output end is connected to the first driving circuit module 50 .

[0041] Specifically, refer to Figure 4The first subtraction circuit module 30 further includes a resistor R1, a resistor R2, a resistor R3, and a resistor R4. The inverting input terminal of the second operational amplifier U2 is connected to the output terminal of the first operational amplifier U1 in the follower circuit module 20 through the resistor R4, and is connected to the output terminal of the second operational amplifier U2 through R3 and connected to the first driving circuit module 50. The non-inverting input terminal of the second operational amplifier U2 is grounded through the resistor R2, and is connected to the reference voltage input through the resistor R1.

[0042] In this embodiment, the second subtraction circuit module 40 includes a third operational amplifier U3 whose input end is connected to the follower circuit module 20 and whose output end is connected to the second driving circuit module 60 .

[0043] Specifically, refer to Figure 4 The second subtraction circuit module 40 also includes a resistor R5, a resistor R6, a resistor R7, and a resistor R8. The non-inverting input terminal of the third operational amplifier U3 is connected to the output terminal of the first operational amplifier U1 in the follower circuit module 20 through the resistor R5, and is grounded through the resistor R6, and the inverting input terminal is connected to the output terminal of the third operational amplifier U3 through R7 and is connected to the second driving circuit module 60, and the inverting input terminal is connected to the reference voltage input through the resistor R8.

[0044] Furthermore, the first driving circuit module 50 includes a first high-voltage amplifier unit connected to the first subtraction circuit module 30 and the first control terminal of the optical filter 300 respectively.

[0045] Among them, reference Figure 4 The first high-voltage amplifier unit includes a fourth operational amplifier, a resistor R9 and a resistor R10 respectively connected to the first subtraction circuit module 30 and the first control terminal of the optical filter 300. Specifically, the non-inverting input terminal of the fourth operational amplifier U4 is connected to the output terminal of the second operational amplifier U2 in the first subtraction circuit module 30 to receive the third analog signal, and the inverting input terminal is grounded through the resistor R9, and is connected to the second control terminal of the optical filter 300 through the resistor R10.

[0046] Furthermore, the second driving circuit module 60 includes a second high-voltage amplifier unit connected to the second subtraction circuit module 40 and the second control terminal of the optical filter 300 respectively.

[0047] Among them, reference Figure 4The second high-voltage amplifier unit includes a fifth operational amplifier U5, a resistor R11 and a resistor R12 respectively connected to the second subtraction circuit module 40 and the second control terminal of the optical filter 300. Specifically, the non-inverting input terminal of the fifth operational amplifier U5 is connected to the output terminal of the third operational amplifier U3 in the second subtraction circuit module 40 to receive the fourth analog signal, and the inverting input terminal is grounded through the resistor R11, and is connected to the second control terminal of the optical filter 300 through the resistor R12.

[0048] The first control terminal and the second control terminal of the optical filter 300 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 processed by the first subtraction circuit module 30 and the second subtraction circuit module 40 is also a low voltage signal. The low voltage signal is amplified by the first high voltage amplifier unit and the second high voltage amplifier unit to drive the optical filter 300.

[0049] In this embodiment, the driving circuit of the optical filter can drive a fixed frequency optical filter 300 or an adjustable optical filter 300. In this embodiment, the optical filter 300 includes an adjustable optical filter 300. In addition, the driving circuit 100 of the optical filter 300 in this embodiment can be applied to optical module products such as EDFA, or used in an instrument for driving the optical filter 300.

[0050] The specific working principle of the driving circuit of the optical filter in the embodiment of the present invention is as follows:

[0051] The low voltage digital-to-analog conversion circuit module 10 converts the external input control signal into an analog signal of 0 to 2.5V (for example only and with limitation), at which time, the reference voltage input of the resistor R1 and the resistor R8 can be set to 1.25V. When the input of the follower circuit module 20 is 0 to 1.25V, the first subtraction circuit module 30 outputs an analog signal of 1.25V to 0V, which is amplified by the first drive circuit module 50 and output to the first control terminal of the optical filter 300; at this time, the second subtraction circuit module 40 outputs 0V; when the input of the follower circuit module 20 is 1.25 to 2.5V, the second subtraction circuit module 40 outputs an analog signal of 0V to 1.25V, which is amplified by the second drive circuit module 60 and output to the second control terminal of the optical filter 300; at this time, the first subtraction circuit module 30 outputs 0V.

[0052] The analog signals output by the first subtraction circuit module 30 and the second subtraction circuit module 40 do not affect each other, and are respectively output to the corresponding control end after passing through the first driving circuit module 50 and the second driving circuit module 60, thereby retaining the advantages of the original unbalanced control while simplifying the circuit control and reducing the control cost.

[0053] like Figures 2 to 4As shown, the present invention also provides a driving system for an optical filter.

[0054] A driving system for an optical filter comprises the driving circuit 100 described above, a control unit 200 whose output end is connected to the driving circuit 100 and outputs a control signal to the driving circuit 100, and an optical filter 300 connected to the driving circuit 100, wherein the driving circuit 100 receives the control signal of the control unit 200 and converts it into a third analog signal and a fourth analog signal, then outputs the third analog signal to the first control end of the optical filter 300, and outputs the fourth analog signal to the second control end of the optical filter 300.

[0055] Specifically, the control unit 200 of the driving system is connected to the low-voltage digital-to-analog conversion circuit module 10 of the driving circuit 100, outputs a control signal to the low-voltage digital-to-analog conversion circuit module 10, the first driving circuit module 50 of the driving circuit 100 is connected to the first control end of the optical filter 300, and the second driving circuit module 60 of the driving circuit 100 is connected to the second control end of the optical filter 300.

[0056] The driving system is provided with a follower circuit module 20, a first subtraction circuit module 30 and a second subtraction circuit module 40, and a low-voltage digital-to-analog conversion circuit module 10 to convert the control signal output by the control unit 200 into a first analog signal. The converted first analog signal is processed by the follower circuit module 20 and the first subtraction circuit module 30 to output a third analog signal, which is then amplified by the first driving circuit module 50 and output to the first control end of the optical filter 300. At the same time, the first analog signal is processed by the follower circuit module 20 and the second subtraction circuit module 40 to output a fourth analog signal, which is then amplified by the second driving circuit module 60 and output to the second control end of the optical filter 300, thereby respectively controlling the first control end and the second control end of the optical filter 300, while maintaining the original unbalanced control, saving a control pin, having a simple circuit structure, simple application, and reducing circuit control cost and software control cost.

[0057] 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 follower 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 after processing; A first subtraction circuit module, whose input end is connected to the follower circuit module to receive the second analog signal and output a third analog signal after processing; A second subtraction circuit module, whose input end is connected to the follower circuit module to receive the second analog signal and output a fourth analog signal after processing; A first driving circuit module is connected to the output end of the first subtraction circuit module to receive the third analog signal and amplify the third analog signal before outputting it to the first control end of the optical filter; The second driving circuit module is connected to the output end of the second subtraction circuit module to receive the fourth analog signal, amplify the fourth analog signal, and then output it to the second control end of the optical filter.

2. The driving circuit according to claim 1, characterized in that: The follower circuit module comprises a first operational amplifier whose input end is connected to the low-voltage digital-to-analog conversion circuit module and whose output end is respectively connected to the first subtraction circuit module and the second subtraction circuit module.

3. The driving circuit according to claim 1, characterized in that: The first subtraction circuit module comprises a second operational amplifier whose input end is connected to the follower circuit module and whose output end is connected to the first driving circuit module.

4. The driving circuit according to claim 3, characterized in that: The second subtraction circuit module comprises a third operational amplifier whose input end is connected to the follower circuit module and whose output end is connected to the second driving circuit module.

5. The driving circuit according to claim 1, characterized in that: The first driving circuit module includes a first high-voltage amplifier unit connected to the first subtraction circuit module and the first control terminal of the optical filter respectively.

6. The driving circuit according to claim 5, characterized in that: The second driving circuit module includes a second high-voltage amplifier unit connected to the second subtraction circuit module and the second control terminal of 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 third analog signal and a fourth analog signal, then outputs the third analog signal to the first control end of the optical filter and outputs the fourth analog signal to the second control end of the optical filter.

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