Method and apparatus for realizing fast locking of different gain of EDFA

Abstract

This invention relates to the field of fiber optic amplification technology, and in particular to a method and apparatus for rapidly locking different gains of an EDFA (Electronic Optical Fiber Amplifier). The method includes: linearly fitting the calibration values ​​of the gain factor and ASE factor corresponding to the maximum and minimum gains within a preset gain range to obtain the gain factor and ASE factor corresponding to each gain within the preset gain range; calibrating the input light within the preset gain range to obtain the relationship between the sampled ADC value and the reported power of the input light corresponding to each gain within the preset gain range; determining the target gain, obtaining the target gain factor, target ASE factor, and target reported power corresponding to the target gain, and obtaining the target input optical power based on the target gain factor, target ASE factor, and target reported power; obtaining the pump DAC value required for the target gain based on the monitored output optical power and the target input optical power, and adjusting the drive current of the pump unit through the pump DAC value to achieve locking of the target gain.

Description

Technical Field

[0001] This invention relates to the field of fiber optic amplification technology, and in particular to a method and apparatus for achieving rapid locking of different gains in an EDFA. Background Technology

[0002] With the development of fiber optic amplification technology, more and more companies are trying to minimize resource investment during product development in order to design erbium-doped optical fiber amplifiers (EDFAs) suitable for low input and different target gains in transmission networks. Compared with traditional fiber optic amplification technology, its internal proportional-integral-derivative (PID) circuit can only quickly lock onto a certain fixed gain point. As other gain points move further away from the calibration gain point, once the set gain changes, the analog-to-digital converter (ADC) sampling of the input photoelectric detector (PD) power will also be affected. The accuracy of the EDFA input PD power reporting becomes worse and worse, and consequently the gain accuracy also becomes worse and worse, which cannot meet the actual needs of EDFA.

[0003] On the other hand, for non-calibrated gain points, traditional gain locking methods generally achieve gain locking at each gain point through advanced process control (APC) software. Specifically, the microcontroller unit (MCU) uses the sum of the input PD, target gain, and corresponding ASE calibration and fitted values—that is, the target output power—to feed back to the PID controller. The MCU then calculates the actual required pump-to-analog converter (DAC) value and feeds it back to the pump-DAC driver circuit. The pump-DAC value required to reach the target gain point is determined through approximation adjustment. While this method can lock different target gains, including non-calibrated points, relatively accurately, the MCU calculation process and the process of driving the pump-DCA circuit to adjust the DAC are time-consuming, significantly reducing the transient performance of the EDFA. Furthermore, adjusting the DAC step size requires experimentally derived empirical values ​​for the gain point, incurring additional development costs and still failing to meet the needs of practical EDFAs.

[0004] Therefore, overcoming the shortcomings of the existing technology is an urgent problem to be solved in this technical field. Summary of the Invention

[0005] The technical problem to be solved by this invention is: how to achieve rapid locking of the gain of EDFA while improving the accuracy of EDFA input PD power reporting and reducing development costs.

[0006] The present invention adopts the following technical solution:

[0007] The first aspect provides a method for fast locking of different gains in EDFA, including:

[0008] Linear fitting is performed on the calibrated values ​​of the gain factors corresponding to the maximum and minimum gains within the preset gain range to obtain the gain factors corresponding to each gain within the preset gain range.

[0009] Linear fitting is performed on the ASE factor corresponding to the maximum and minimum gains within the preset gain range to obtain the ASE factor corresponding to each gain within the preset gain range.

[0010] Within the preset gain range, the input light is calibrated to obtain the relationship between the sampled ADC value and the reported power of the input light corresponding to each gain within the preset gain range;

[0011] Determine the target gain, obtain the target gain factor, target ASE factor and target reported power corresponding to the target gain, and obtain the target input optical power based on the target gain factor, target ASE factor and target reported power;

[0012] The pump DAC value required for the target gain is obtained based on the monitored output optical power and the target input optical power. The drive current of the pump unit is adjusted by the pump DAC value to lock the target gain.

[0013] Preferably, the linear fitting of the calibration values ​​of the gain factors corresponding to the maximum and minimum gains within the preset gain range to obtain the gain factors corresponding to each gain within the preset gain range includes:

[0014] The gain factors of the maximum gain and the minimum gain are calibrated respectively to obtain the calibrated values ​​of the gain factors of the maximum gain and the minimum gain.

[0015] Linear fitting is performed on the milliwatt value corresponding to the maximum gain, the milliwatt value corresponding to the minimum gain, the gain factor corresponding to the maximum gain, and the gain factor corresponding to the minimum gain to obtain the gain factor relationship, so as to obtain the gain factor corresponding to each gain within the preset gain range according to the gain factor relationship.

[0016] Preferably, the step of scaling the gain factors of the maximum gain and the minimum gain respectively to obtain the scaled values ​​of the gain factors of the maximum gain and the minimum gain includes:

[0017] Obtain the highest output optical power corresponding to the preset gain range;

[0018] The input optical power PH corresponding to the maximum gain is determined based on the maximum output optical power and the maximum gain;

[0019] The amplifier is driven by the input optical power PH, and the gain factor of the amplifier is adjusted until the actual gain obtained by the test is equal to the maximum gain, so as to obtain the calibration value of the gain factor of the maximum gain.

[0020] The input optical power PL corresponding to the minimum gain is determined based on the maximum output optical power and the minimum gain;

[0021] The amplifier is driven by the input optical power PL, and the gain factor of the amplifier is adjusted until the actual gain obtained by testing is equal to the minimum gain, so as to obtain the calibration value of the gain factor of the minimum gain.

[0022] Preferably, the linear fitting of the calibration values ​​of the ASE factors corresponding to the maximum and minimum gains within the preset gain range to obtain the ASE factors corresponding to each gain within the preset gain range includes:

[0023] The ASE factors of the maximum gain and minimum gain are calibrated respectively to obtain the calibrated values ​​of the ASE factors of the maximum gain and minimum gain.

[0024] Linear fitting is performed on the milliwatt value corresponding to the maximum gain, the milliwatt value corresponding to the minimum gain, the ASE factor corresponding to the maximum gain, and the ASE factor corresponding to the minimum gain to obtain the ASE factor relationship, and the ASE factor corresponding to each gain is obtained according to the ASE factor relationship.

[0025] Preferably, the calibration of the ASE factors for the maximum and minimum gains to obtain the calibrated values ​​of the ASE factors for the maximum and minimum gains includes:

[0026] Obtain the minimum output optical power corresponding to the preset gain range;

[0027] The input optical power PH' corresponding to the maximum gain is determined based on the minimum output optical power and the maximum gain;

[0028] The amplifier is driven by the input optical power PH', and the ASE factor of the amplifier is adjusted until the actual gain obtained by the test is equal to the maximum gain, so as to obtain the calibration value of the ASE factor of the maximum gain;

[0029] The input optical power PL' corresponding to the minimum gain is determined based on the minimum output optical power and the minimum gain;

[0030] The amplifier is driven by the input optical power PL', and the ASE factor of the amplifier is adjusted until the actual gain obtained by the test is equal to the minimum gain, so as to obtain the calibration value of the ASE factor of the minimum gain.

[0031] Preferably, the step of calibrating the input light within the preset gain range to obtain the relationship between the sampled ADC value and the reported power of the input light corresponding to each gain within the preset gain range includes:

[0032] A preset input optical power range is defined, which is then divided into a first optical power range and a second optical power range based on the magnitude of the optical power.

[0033] Take the maximum gain, set the input optical power according to the first optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the first relationship between the reported power and the sampled ADC value: reported power = K1_h × X + B1_h, where X is the sampled ADC value, and K1_h and B1_h are constants;

[0034] Take the maximum gain, set the input optical power according to the second optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the second relationship between the reported power and the sampled ADC value: reported power = K1_l × X + B1_l, where X is the sampled ADC value, and K1_l and B1_l are constants;

[0035] Take the minimum gain, set the input optical power according to the first optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the third relationship between the reported power and the sampled ADC value: reported power = K2_h × X + B2_h, where X is the sampled ADC value, and K2_h and B2_h are constants;

[0036] Take the minimum gain, set the input optical power according to the second optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the fourth relationship between the reported power and the sampled ADC value: reported power = K2_l × X + B2_l, where X is the sampled ADC value, and K2_l and B2_l are constants;

[0037] The relationship between the sampled ADC value and the reported power is derived based on the first, second, third, and fourth relationships.

[0038] Preferably, the step of deriving the relationship between the sampled ADC value and the reported power based on the first relationship, the second relationship, the third relationship, and the fourth relationship includes:

[0039] Linearly fit K1_h and K2_h with the maximum gain and minimum gain, that is, take the minimum gain as the x-axis and K2_h as the y-axis as the first fitting point, take the maximum gain as the x-axis and K1_h as the y-axis as the second fitting point, and linearly fit the first fitting point and the second fitting point to obtain the slope factor K_h_factor.

[0040] Linearly fit K1_l and K2_l with the maximum gain and minimum gain, that is, take the minimum gain as the x-axis and K2_l as the y-axis as the third fitting point, take the maximum gain as the x-axis and K1_l as the y-axis as the fourth fitting point, and linearly fit the third fitting point and the fourth fitting point to obtain the slope factor K_l_factor.

[0041] Linearly fit B1_h and B2_h with the milliwatt values ​​corresponding to the maximum gain and the minimum gain, respectively. Specifically, use the milliwatt value corresponding to the minimum gain as the x-axis and B2_h as the y-axis as the fifth fitting point, and use the milliwatt value corresponding to the maximum gain as the x-axis and B1_h as the y-axis as the sixth fitting point. Linearly fit the fifth fitting point and the sixth fitting point to obtain the offset factor B_h_offset.

[0042] Linearly fit B1_l and B2_l to the milliwatt values ​​corresponding to the maximum gain and the minimum gain, respectively. Specifically, use the milliwatt value corresponding to the minimum gain as the x-axis and B2_l as the y-axis as the seventh fitting point, and use the milliwatt value corresponding to the maximum gain as the x-axis and B1_l as the y-axis as the eighth fitting point. Linearly fit the seventh fitting point and the eighth fitting point to obtain the offset factor B_l_offset.

[0043] The following values ​​are obtained respectively: reported power = K_h_factor×ADC+B_h_offset, reported power = K_h_factor×ADC+B_l_offset, reported power = K_l_factor×ADC+B_h_offset, and reported power = K_l_factor×ADC+B_l_offset, so as to obtain the relationship between the sampled ADC value of the input light and the reported power corresponding to each gain within the preset gain range.

[0044] Preferably, the amplifier includes a digital potentiometer and a PID control circuit;

[0045] The process of determining the target gain, obtaining the target gain factor, target ASE factor, and target reported power corresponding to the target gain, and obtaining the target input optical power based on the target gain factor, target ASE factor, and target reported power includes:

[0046] For any target gain within the preset gain range, the PID control circuit acquires the target gain factor, target ASE factor, and target reported power corresponding to the target gain.

[0047] The resistance value of the digital potentiometer is controlled by the target gain factor;

[0048] The power of the target ASE factor is added to the target reported power to obtain the target input optical power.

[0049] Preferably, the step of obtaining the pump DAC value required for the target gain based on the monitored output optical power and the target input optical power, and adjusting the drive current of the pump unit through the pump DAC value to lock the target gain, specifically involves:

[0050] The target input optical power is used as the first input to the PID control circuit.

[0051] The output optical power is used as the second input of the PID control circuit;

[0052] The PID control circuit obtains a control error signal based on the difference between the first input and the second input;

[0053] The control error signal serves as the input to the pump DAC. The digital potentiometer controls the drive current of the pump unit to obtain the required pump DAC value at the target gain. The signal is then used as the drive current to directly drive the pump unit to adjust the current, thereby locking the target gain.

[0054] Secondly, a device for rapidly locking different gains of EDFA is provided, including: a gain factor fitting module, an ASE factor fitting module, an input light calibration module, an acquisition module, and a locking module;

[0055] The gain factor fitting module is used to perform linear fitting on the calibration values ​​of the gain factors corresponding to the maximum and minimum gains within a preset gain range, so as to obtain the gain factors corresponding to each gain within the preset gain range.

[0056] The ASE factor fitting module is used to perform linear fitting on the calibration values ​​of the ASE factors corresponding to the maximum and minimum gains within a preset gain range, so as to obtain the ASE factors corresponding to each gain within the preset gain range.

[0057] The input light calibration module is used to calibrate the input light within the preset gain range to obtain the relationship between the sampled ADC value and the reported power of the input light corresponding to each gain within the preset gain range.

[0058] The obtaining module is used to determine the target gain, obtain the target gain factor, target ASE factor and target reported power corresponding to the target gain, and obtain the target input optical power based on the target gain factor, target ASE factor and target reported power;

[0059] The locking module is used to obtain the pump DAC value required for the target gain based on the monitored output optical power and the target input optical power, and adjust the drive current of the pump unit through the pump DAC value to lock the target gain.

[0060] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0061] This invention obtains the gain factor, ASE factor, and reported power corresponding to each gain point within a preset gain range by performing linear fitting on the calibration values ​​of the gain factor, ASE factor, and reported power at the maximum and minimum gain points within the preset gain range. After confirming the target gain, the target gain factor, target ASE factor, and target reported power corresponding to the target gain are obtained. The target input optical power is obtained based on the target gain factor, target ASE factor, and target reported power. The pump DAC value required for the target gain is obtained based on the monitored output optical power and the target input optical power. The driving current of the pump unit is adjusted by the pump DAC value to lock the target gain. This improves the accuracy of EDFA reported power without increasing development costs and achieves rapid gain locking of the EDFA. Attached Figure Description

[0062] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0063] Figure 1 This is a schematic diagram of the structure of an EDFA, which is a method for fast locking of different gains in an EDFA according to an embodiment of the present invention.

[0064] Figure 2 This is a schematic diagram of the hardware control unit for a method of fast locking of different gains in EDFA provided in an embodiment of the present invention;

[0065] Figure 3 This is a flowchart illustrating a method for fast locking of different gains in EDFA according to an embodiment of the present invention;

[0066] Figure 4 This is a flowchart illustrating the gain factor calibration process for a method of fast locking of different gains in EDFA provided by an embodiment of the present invention.

[0067] Figure 5 This is a flowchart illustrating the ASE factor calibration process for a method of rapidly locking different gains of EDFA provided in an embodiment of the present invention.

[0068] Figure 6 This is a schematic diagram of the PID control structure for a method of fast locking of different gains of EDFA provided in an embodiment of the present invention;

[0069] Figure 7 This is a schematic diagram of a device for rapidly locking different gains of an EDFA according to an embodiment of the present invention. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0071] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0072] In this application, unless otherwise expressly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0073] Example 1

[0074] To address the problems existing in the prior art, this embodiment proposes a method for fast locking of different EDFA gains. The optical network architecture implementing this method includes one or more EDFA amplifiers, such as... Figure 1 As shown, each EDFA amplifier includes: an input optical PD, an optical isolator 1, a wavelength division multiplexer 1, a 980 pump laser, an erbium-doped fiber, an output optical PD, an optical isolator 2, and a hardware control unit. The input terminal of the optical isolator 1 serves as the input port of the EDFA amplifier. The output terminal of the optical isolator 1 is connected to the input terminal of the wavelength division multiplexer 1. The pump terminal of the wavelength division multiplexer is connected to the 980 pump laser. The output terminal of the wavelength division multiplexer 1 is connected to the input terminal of the optical isolator 2. The output terminal of the optical isolator 2 is connected to the input terminal of the output optical PD. The output terminal of the output optical PD is used to output amplified signal light. The hardware control unit is as follows: Figure 2 As shown, it includes: PID control circuit, 980 pump drive circuit, input PD detection circuit, output PD detection circuit and MCU. The specific connection relationship and implementation principle are not explained in detail in this embodiment.

[0075] like Figure 3 As shown, the method includes:

[0076] Step 101: Perform linear fitting on the calibration values ​​of the gain factors corresponding to the maximum and minimum gains within the preset gain range to obtain the gain factors corresponding to each gain within the preset gain range.

[0077] Among them, such as Figure 4 Step 1011: Calibrate the gain factors of the maximum gain and the minimum gain respectively to obtain the calibrated values ​​of the gain factors of the maximum gain and the minimum gain.

[0078] Specifically, this includes: obtaining the highest output optical power corresponding to the preset gain range; determining the input optical power PH corresponding to the maximum gain based on the highest output optical power and the maximum gain; driving an amplifier with the input optical power PH and adjusting the gain factor of the amplifier until the actual gain obtained by testing is equal to the maximum gain, thereby obtaining a calibration value of the gain factor of the maximum gain; determining the input optical power PL corresponding to the minimum gain based on the highest output optical power and the minimum gain; driving an amplifier with the input optical power PL and adjusting the gain factor of the amplifier until the actual gain obtained by testing is equal to the minimum gain, thereby obtaining a calibration value of the gain factor of the minimum gain.

[0079] In a preferred embodiment, for example, a preset gain range of 0-20dB is determined, the maximum gain Gmax is 20dB, and the minimum gain Gmin is 0dB. The maximum output optical power Pout_max of the amplifier is determined through an amplifier parameter table or actual measurement. Then, the input light source of the amplifier is connected to the input terminal of the amplifier, and the optical power meter is connected to the output terminal of the amplifier. The optical power of the input light source is adjusted and recorded when the output optical power of the amplifier reaches Pout_max. This value of the input light source is denoted as PH. The amplifier is driven by PH as the input optical power to adjust the internal gain regulator of the amplifier. The output optical power and the test gain value are observed. When the test gain value reaches Gmax=20dB, the position of the gain regulator at this time is recorded as the calibration gain factor Gh_max. The optical power of the input light source is reduced to the minimum value PL that can drive the amplifier to work. Then, the above steps are repeated. When the target test gain is Gmin=0dB, the calibration gain factor Gl_min is recorded. That is, Gh_max and Gl_min are the calibration values ​​of the gain factor of the maximum gain and the gain factor of the minimum gain, respectively.

[0080] Step 1012: Perform linear fitting on the milliwatt value corresponding to the maximum gain, the milliwatt value corresponding to the minimum gain, the gain factor corresponding to the maximum gain, and the gain factor corresponding to the minimum gain to obtain the gain factor relationship, so as to obtain the gain factor corresponding to each gain within the preset gain range according to the gain factor relationship.

[0081] In a preferred embodiment, the calibration gain factor corresponding to the maximum gain and the calibration gain factor corresponding to the minimum gain are linearly fitted. Since the gain factor and the gain value are linearly related, the linear fitting can be used to obtain the linear relationship between the gain factor Gh and the gain value G: Gh = k1 × G + b1, (k1 and b1 are constants, × means multiplication), where k1 is the slope and b1 is the intercept. By substituting the two points (maximum gain Gmax, gain factor Gh_max) and (minimum gain Gmin, gain factor Gl_min) into Gh = k1 × G + b1 for linear fitting, the values ​​of k1 and b1 can be calculated. Thus, the relationship between the gain factor Gh and the gain value G is obtained.

[0082] Furthermore, based on the preset gain range, the gain factor Gh corresponding to each gain value G within the gain range can be calculated.

[0083] Step 102: Perform linear fitting on the calibration values ​​of the ASE factors corresponding to the maximum and minimum gains within the preset gain range to obtain the ASE factors corresponding to each gain within the preset gain range.

[0084] Among them, such as Figure 5 Step 1021: Calibrate the ASE factors of the maximum gain and minimum gain respectively to obtain the calibrated values ​​of the ASE factors of the maximum gain and minimum gain.

[0085] Specifically, the process includes: obtaining the minimum output optical power corresponding to the preset gain range; determining the input optical power PH' corresponding to the maximum gain based on the minimum output optical power and the maximum gain; driving an amplifier with the input optical power PH' and adjusting the ASE factor of the amplifier until the actual gain obtained by testing is equal to the maximum gain, thereby obtaining a calibration value of the ASE factor of the maximum gain; determining the input optical power PL' corresponding to the minimum gain based on the minimum output optical power and the minimum gain; driving an amplifier with the input optical power PL' and adjusting the ASE factor of the amplifier until the actual gain obtained by testing is equal to the minimum gain, thereby obtaining a calibration value of the ASE factor of the minimum gain.

[0086] In a preferred embodiment, for example, a preset gain range of 0-20dB is determined, with a maximum gain of 20dB and a minimum gain of 0dB. The minimum output optical power Pout_min of the amplifier is determined through amplifier technical parameters or actual measurements. The amplifier input is connected to a light source, and the output is connected to an optical power meter. The input light source power is adjusted, and the input optical power value at which the output optical power reaches Pout_min is recorded and set as PH'. Then, using PH' as input, the amplifier is driven to work, and the internal ASE regulator is adjusted. The output optical power and the test gain value are observed. When the test gain value is 20dB, the ASE regulator position is recorded as the ASE calibration value for the maximum gain. The input light source power is then reduced slightly and set to PL'. The above steps are repeated until the target test gain is 0dB. The minimum gain ASE calibration value is recorded. The ASE calibration values ​​corresponding to the maximum and minimum gains are obtained in the above manner.

[0087] Step 1022: Perform linear fitting on the milliwatt value corresponding to the maximum gain, the milliwatt value corresponding to the minimum gain, the ASE factor corresponding to the maximum gain, and the ASE factor corresponding to the minimum gain to obtain the ASE factor relationship, so as to obtain the ASE factor corresponding to each gain according to the ASE factor relationship.

[0088] In a preferred embodiment, the calibration ASE factor corresponding to the maximum gain and the calibration ASE factor corresponding to the minimum gain are linearly fitted. Since the ASE factor and the gain value are linearly related, the linear fitting can be used to obtain the linear relationship between the ASE factor GA and the gain value G: GA = k2 × G + b2, (k2 and b2 are constants, × means multiplication), where k2 is the slope and b2 is the intercept. The values ​​of k2 and b2 can be calculated by linear fitting the two points (maximum gain, ASE factor) and (minimum gain, ASE factor), thus obtaining the relationship between the ASE factor GA and the gain value G. The specific implementation steps are similar to the calibration process of the gain factor.

[0089] Furthermore, based on the preset gain range, the ASE factor GA corresponding to each gain value G can be calculated.

[0090] Step 103: Within the preset gain range, calibrate the input light to obtain the relationship between the sampling ADC value and the reported power of the input light corresponding to each gain within the preset gain range.

[0091] A preset input optical power range is defined, which is divided into a first optical power range and a second optical power range according to the magnitude of the optical power. The first optical power range is the higher optical power range within the input optical power range, and the second optical power range is the lower optical power range within the input optical power range. In other words, the preset input optical power range is taken as the middle value. The input optical power is greater than or equal to the middle value and belongs to the first optical power range, while the input optical power is less than the middle value and belongs to the second optical power range.

[0092] In a preferred embodiment, the reported power of the first optical power range and the second optical power range within the gain range is covered by the following four cases:

[0093] Case 1: Under the conditions of maximum gain and high optical power range, take the maximum gain, set the input optical power according to the first optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the first relationship between the reported power and the sampled ADC value: reported power = K1_h × X + B1_h, where X is the sampled ADC value, and K1_h and B1_h are constants.

[0094] Case 2: Under the conditions of maximum gain and lower optical power range, take the maximum gain, set the input optical power according to the second optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the second relationship between the reported power and the sampled ADC value: reported power = K1_l × X + B1_l, where X is the sampled ADC value, and K1_l and B1_l are constants.

[0095] Case 3: Under the minimum gain and higher optical power range, take the minimum gain, set the input optical power according to the first optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the third relationship between the reported power and the sampled ADC value: reported power = K2_h × X + B2_h, where X is the sampled ADC value, and K2_h and B2_h are constants.

[0096] Case 4: Under the minimum gain and lower optical power range, take the minimum gain, set the input optical power according to the second optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the fourth relationship between the reported power and the sampled ADC value: reported power = K2_l × X + B2_l, where X is the sampled ADC value, and K2_l and B2_l are constants.

[0097] Based on the above four scenarios, in the preferred embodiment, the maximum gain value is first set, for example, 20dB.

[0098] Set the input optical PD to the first power level (i.e., a higher power level). Based on the preset first optical power range, such as 10-20mW, set several input optical power values, such as 11mW, 16mW, 19mW, etc., at intervals. Input these optical power values ​​into the amplifier respectively, and record the sampling ADC values ​​sampled by the input optical PD. Perform linear fitting between these sets of input optical power milliwatt values ​​and the corresponding sampling ADC values ​​to obtain the first relationship. Then switch the input optical PD to the second power level (i.e., a lower power level), based on the preset second optical power range, such as 0-10mW, and repeat the above steps to obtain the second relationship.

[0099] Set the gain to the minimum value, for example, 0dB, and repeat the above steps at the first power level and the second power level respectively to obtain the third relationship and the fourth relationship. The specific process is not described in this embodiment.

[0100] Based on the first, second, third, and fourth relationships, the relationship between the sampled ADC value and the reported power is derived. Then, K1_h and K2_h are linearly fitted with the maximum gain and minimum gain; K1_l and K2_l are linearly fitted with the maximum gain and minimum gain; B1_h and B2_h are linearly fitted with the milliwatt values ​​corresponding to the maximum gain and minimum gain; and B1_l and B2_l are linearly fitted with the milliwatt values ​​corresponding to the maximum gain and minimum gain.

[0101] The following values ​​are obtained respectively: reported power = K_h_factor×ADC+B_h_offset, reported power = K_h_factor×ADC+B_l_offset, reported power = K_l_factor×ADC+B_h_offset, and reported power = K_l_factor×ADC+B_l_offset, so as to obtain the relationship between the sampled ADC value of the input light and the reported power corresponding to each gain within the preset gain range.

[0102] The main processes are as follows:

[0103] Linearly fit K1_h and K2_h with the maximum gain and minimum gain, that is, take the minimum gain as the x-axis and K2_h as the y-axis as the first fitting point, take the maximum gain as the x-axis and K1_h as the y-axis as the second fitting point, and linearly fit the first fitting point and the second fitting point to obtain the slope factor K_h_factor.

[0104] Linearly fit K1_l and K2_l with the maximum gain and minimum gain, that is, take the minimum gain as the x-axis and K2_l as the y-axis as the third fitting point, take the maximum gain as the x-axis and K1_l as the y-axis as the fourth fitting point, and linearly fit the third fitting point and the fourth fitting point to obtain the slope factor K_l_factor.

[0105] Linearly fit B1_h and B2_h with the milliwatt values ​​corresponding to the maximum gain and the minimum gain, respectively. Specifically, use the milliwatt value corresponding to the minimum gain as the x-axis and B2_h as the y-axis as the fifth fitting point, and use the milliwatt value corresponding to the maximum gain as the x-axis and B1_h as the y-axis as the sixth fitting point. Linearly fit the fifth fitting point and the sixth fitting point to obtain the offset factor B_h_offset.

[0106] Linearly fit B1_l and B2_l to the milliwatt values ​​corresponding to the maximum gain and the minimum gain, respectively. Specifically, use the milliwatt value corresponding to the minimum gain as the x-axis and B2_l as the y-axis as the y-axis to obtain the seventh fitting point, and use the milliwatt value corresponding to the maximum gain as the x-axis and B1_l as the y-axis as the y-axis to obtain the eighth fitting point. Linearly fit the seventh fitting point and the eighth fitting point to obtain the offset factor B_l_offset.

[0107] The following four formulas are obtained:

[0108] The reported power is calculated as follows: K_h_factor × ADC + B_h_offset, applicable to the first optical power range; K_l_factor × ADC + B_h_offset, applicable to the second optical power range; K_h_factor × ADC + B_l_offset, applicable to the first optical power range; K_l_factor × ADC + B_l_offset, applicable to the second optical power range. Using these four formulas and automatic module level switching, the corresponding reported power can be calculated based on any gain value and ADC sampling value. Furthermore, the ADC sampling value and the target gain have the following linear relationship: ADC = f × I PD ×Rg+q, (ADC represents the ADC sampled value, f and q represent constants, I) PD Rg represents the current input to the PD and Rg represents the resistance of the digital potentiometer. The magnitude of the ADC sampled value is related to the gain factor, which in turn corresponds to the gain. The principle is to integrate multiple relationships into four formulas to describe the mapping relationship between gain, ADC sampled value, and reported power, thereby achieving accurate calculation of the reported power.

[0109] Step 104: Determine the target gain, obtain the target gain factor, target ASE factor and target reported power corresponding to the target gain, and obtain the target input optical power based on the target gain factor, target ASE factor and target reported power.

[0110] The amplifier also includes a digital potentiometer; such as Figure 6 As shown, for any target gain within the preset gain range, the PID control circuit acquires the target gain factor, target ASE factor, and target reported power corresponding to the target gain; controls the resistance value of the digital potentiometer through the target gain factor; and adds the power of the target ASE factor to the target reported power as the target input optical power.

[0111] The amplifier system also includes a digital potentiometer whose resistance can be controlled by a digital signal. For any target gain within a preset gain range, the PID control circuit can obtain: the target gain factor, the target ASE factor, and the target reported optical power corresponding to the target gain. By controlling the resistance of the digital potentiometer through the target gain factor, the target gain is achieved. The ASE light source power represented by the target ASE factor is added to the target reported optical power as the target input optical power of the entire amplifier. This process achieves the target gain by controlling the amplifier gain through the digital potentiometer. The actual target input optical power after considering the influence of the ASE light source is calculated. Thus, it is possible to accurately control the amplifier input optical power by controlling the target gain under any target gain. The entire process utilizes the digital potentiometer and ASE light source compensation to achieve joint control of amplifier gain and input optical power to achieve different target values.

[0112] Step 105: Obtain the pump DAC value required for the target gain based on the monitored output optical power and the target input optical power, and adjust the drive current of the pump unit through the pump DAC value to lock the target gain.

[0113] The amplifier further includes a PID control circuit; the target input optical power is used as the first input of the PID control circuit; the output optical power is used as the second input of the PID control circuit; the PID control circuit obtains a control error signal based on the difference between the first input and the second input; the control error signal is used as the input of the pump DAC, and the driving current of the pump unit is controlled by the digital potentiometer to obtain the pump DAC value required at the target gain, and the driving current is used to directly drive the pump unit to adjust the current, so as to lock the target gain.

[0114] Reference Figure 6The PID control circuit uses the target input optical power as the first input and the measured output optical power as the second input. Based on the difference between these two inputs, i.e., the control error, the PID control circuit calculates a control error signal, which serves as the input to the pump DAC. A digital potentiometer controls the drive current of the pump unit to obtain the required pump DAC value at the target gain. The obtained pump DAC value then directly drives the pump unit, adjusting its current in real time. The PID control circuit performs negative feedback control on the output optical power and the target input optical power, and through the joint adjustment of the digital potentiometer and the pump unit, it achieves the locking and maintenance of the target gain. In this way, the amplifier system can stably operate at the preset target gain level under different conditions. The entire process adopts the PID control principle, achieving negative feedback locking control of the target state through the joint adjustment of the digital potentiometer and the pump unit. The PID control principle will not be explained in detail in this embodiment.

[0115] This invention obtains the gain factor, ASE factor, and reported power corresponding to each gain point within a preset gain range by performing linear fitting on the calibration values ​​of the gain factor, ASE factor, and reported power at the maximum and minimum gain points within the preset gain range. After confirming the target gain, the target gain factor, target ASE factor, and target reported power corresponding to the target gain are obtained. The target input optical power is obtained based on the target gain factor, target ASE factor, and target reported power. The pump DAC value required for the target gain is obtained based on the monitored output optical power and the target input optical power. The driving current of the pump unit is adjusted by the pump DAC value to lock the target gain. This improves the accuracy of EDFA reported power without increasing development costs and achieves rapid gain locking of the EDFA.

[0116] Example 2

[0117] In Example 1, a method for fast locking of different gains in an EDFA was proposed. In this example, an apparatus for fast locking of different gains in an EDFA will be proposed, such as... Figure 7 As shown, it includes: gain factor fitting module, ASE factor fitting module, input light calibration module, acquisition module and locking module.

[0118] The gain factor fitting module is used to linearly fit the calibration values ​​of the gain factors corresponding to the maximum and minimum gains within a preset gain range to obtain the gain factors corresponding to each gain within the preset gain range; the ASE factor fitting module is used to linearly fit the calibration values ​​of the ASE factors corresponding to the maximum and minimum gains within a preset gain range to obtain the ASE factors corresponding to each gain within the preset gain range; the input light calibration module is used to calibrate the input light within the preset gain range to obtain the relationship between the sampling ADC value and the reported power of the input light corresponding to each gain within the preset gain range; the acquisition module is used to determine the target gain, obtain the target gain factor, target ASE factor, and target reported power corresponding to the target gain, and obtain the target input light power based on the target gain factor, target ASE factor, and target reported power; the locking module is used to obtain the pump DAC value required for the target gain based on the monitored output light power and the target input light power, and adjust the drive current of the pump unit through the pump DAC value to achieve locking of the target gain.

[0119] The specific steps of the method for achieving fast locking of different gains in EDFA are described in Example 1, and will not be repeated in this example.

[0120] Example 3

[0121] This embodiment will provide an example of a method for quickly locking different gains in an EDFA to further illustrate the present invention. For example, the preset gain range is 10~20dB, the input light range is -33~3dBm, and the output light range is -13~13dBm. Based on these conditions, the GAIN factor can be pre-calibrated; that is, when the output light is 13dBm, the target gain is 10dB, and the input light is 3dBm, the GAIN factor corresponding to 10dB is obtained.

[0122] First, the gain factor corresponding to each gain within the calibration gain range is the ASE factor (the specific implementation method is shown in Example 1).

[0123] Then, the input light is calibrated under different target gains to obtain the relationship between the sampled ADC value and the reported power of the input light corresponding to each gain within the preset gain range (the specific implementation method is shown in Example 1).

[0124] Based on the calibration results above, for any target gain and input optical power, such as a target gain of 15dB and an input optical power of -5dBm, the PID control circuit can directly obtain the gain factor, ASE factor and reported power corresponding to 15dB.

[0125] The ASE light source power, represented by the target ASE factor, is added to the target reported optical power to obtain the target input optical power for the entire amplifier. The PID control circuit uses the target input optical power as the first input and the measured output optical power as the second input. Based on the difference between these two inputs, i.e., the control error, the PID control circuit calculates a control error signal, which serves as the input to the pump DAC. A digital potentiometer controls the drive current of the pump unit to obtain the required pump DAC value at the target gain. The obtained pump DAC value then directly drives the pump unit, adjusting its current in real time. The PID control circuit performs negative feedback control on the output optical power and the target input optical power, and the combined adjustment of the digital potentiometer and the pump unit achieves the locking and maintenance of the target gain. The PID control principle will not be elaborated upon in this embodiment.

[0126] The specific steps of the method for fast locking of different gains of EDFA are described in Example 1, and will not be repeated in this example.

[0127] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for fast locking of different gains in an EDFA, characterized in that, include: Linear fitting is performed on the calibrated values ​​of the gain factors corresponding to the maximum and minimum gains within the preset gain range to obtain the gain factors corresponding to each gain within the preset gain range. Linear fitting is performed on the ASE factor corresponding to the maximum and minimum gains within the preset gain range to obtain the ASE factor corresponding to each gain within the preset gain range. Within the preset gain range, the input light is calibrated to obtain the relationship between the sampled ADC value and the reported power of the input light corresponding to each gain within the preset gain range. Specifically, this includes: dividing the preset input light power range into two light power ranges; setting different input light powers for each of the two light power ranges at the maximum and minimum gains of the preset gain range and recording the corresponding ADC sample values; and linearly fitting the sampled ADC values ​​with the milliwatt values ​​corresponding to the actual input light power to obtain four initial relationships between the reported power and the sampled ADC values ​​for each interval and each gain. For each of the two optical power ranges, the slope constants in the two initial relationships are linearly fitted with the maximum gain and the minimum gain, respectively, to obtain two slope factors; the offset constants in the two initial relationships are linearly fitted with the milliwatt values ​​corresponding to the maximum gain and the minimum gain, respectively, to obtain two offset factors, thereby obtaining four sets of relationships between the sampled ADC value of the input light and the reported power corresponding to each gain within the preset gain range. Determine the target gain, obtain the target gain factor, target ASE factor and target reported power corresponding to the target gain, and obtain the target input optical power based on the target gain factor, target ASE factor and target reported power; The pump DAC value required for the target gain is obtained based on the monitored output optical power and the target input optical power. The drive current of the pump unit is adjusted by the pump DAC value to lock the target gain.

2. The method for fast locking of different gains in an EDFA according to claim 1, characterized in that, The linear fitting of the calibration values ​​of the gain factors corresponding to the maximum and minimum gains within the preset gain range yields the gain factors corresponding to each gain within the preset gain range, including: The gain factors of the maximum gain and the minimum gain are calibrated respectively to obtain the calibrated values ​​of the gain factors of the maximum gain and the minimum gain. Linear fitting is performed on the milliwatt value corresponding to the maximum gain, the milliwatt value corresponding to the minimum gain, the gain factor corresponding to the maximum gain, and the gain factor corresponding to the minimum gain to obtain the gain factor relationship, so as to obtain the gain factor corresponding to each gain within the preset gain range according to the gain factor relationship.

3. The method for fast locking of different gains in an EDFA according to claim 2, characterized in that, The step of calibrating the gain factors of the maximum and minimum gains respectively to obtain the calibrated values ​​of the gain factors of the maximum and minimum gains includes: Obtain the highest output optical power corresponding to the preset gain range; The input optical power PH corresponding to the maximum gain is determined based on the maximum output optical power and the maximum gain; The amplifier is driven by the input optical power PH, and the gain factor of the amplifier is adjusted until the actual gain obtained by the test is equal to the maximum gain, so as to obtain the calibration value of the gain factor of the maximum gain. The input optical power PL corresponding to the minimum gain is determined based on the maximum output optical power and the minimum gain; The amplifier is driven by the input optical power PL, and the gain factor of the amplifier is adjusted until the actual gain obtained by testing is equal to the minimum gain, so as to obtain the calibration value of the gain factor of the minimum gain.

4. The method for fast locking of different gains in an EDFA according to claim 1, characterized in that, The calibration values ​​of the ASE factors corresponding to the maximum and minimum gains within the preset gain range are linearly fitted to obtain the ASE factors corresponding to each gain within the preset gain range, including: The ASE factors of the maximum gain and minimum gain are calibrated respectively to obtain the calibrated values ​​of the ASE factors of the maximum gain and minimum gain. Linear fitting is performed on the milliwatt value corresponding to the maximum gain, the milliwatt value corresponding to the minimum gain, the ASE factor corresponding to the maximum gain, and the ASE factor corresponding to the minimum gain to obtain the ASE factor relationship, and the ASE factor corresponding to each gain is obtained according to the ASE factor relationship.

5. The method for fast locking of different gains in an EDFA according to claim 4, characterized in that, The calibration of the ASE factors for the maximum and minimum gains, respectively, to obtain the calibrated values ​​of the ASE factors for the maximum and minimum gains includes: Obtain the minimum output optical power corresponding to the preset gain range; The input optical power PH' corresponding to the maximum gain is determined based on the minimum output optical power and the maximum gain; The amplifier is driven by the input optical power PH', and the ASE factor of the amplifier is adjusted until the actual gain obtained by the test is equal to the maximum gain, so as to obtain the calibration value of the ASE factor of the maximum gain; The input optical power PL' corresponding to the minimum gain is determined based on the minimum output optical power and the minimum gain; The amplifier is driven by the input optical power PL', and the ASE factor of the amplifier is adjusted until the actual gain obtained by the test is equal to the minimum gain, so as to obtain the calibration value of the ASE factor of the minimum gain.

6. The method for fast locking of different gains in an EDFA according to claim 1, characterized in that, The step of calibrating the input light within the preset gain range to obtain the relationship between the sampled ADC value and the reported power of the input light corresponding to each gain within the preset gain range includes: A preset input optical power range is defined, which is then divided into a first optical power range and a second optical power range based on the magnitude of the optical power. Take the maximum gain, set the input optical power according to the first optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the first relationship between the reported power and the sampled ADC value: reported power = K1_h × X + B1_h, where X is the sampled ADC value, and K1_h and B1_h are constants; Take the maximum gain, set the input optical power according to the second optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the second relationship between the reported power and the sampled ADC value: reported power = K1_l × X + B1_l, where X is the sampled ADC value, and K1_l and B1_l are constants; Take the minimum gain, set the input optical power according to the first optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the third relationship between the reported power and the sampled ADC value: reported power = K2_h × X + B2_h, where X is the sampled ADC value, and K2_h and B2_h are constants; Take the minimum gain, set the input optical power according to the second optical power range, record the ADC sampling value corresponding to each optical power, fit the ADC sampling value with the milliwatt value corresponding to the actual input optical power of the amplifier, and obtain the fourth relationship between the reported power and the sampled ADC value: reported power = K2_l × X + B2_l, where X is the sampled ADC value, and K2_l and B2_l are constants; The relationship between the sampled ADC value and the reported power is derived based on the first, second, third, and fourth relationships.

7. The method for fast locking of different gains in an EDFA according to claim 6, characterized in that, The step of deriving the relationship between the sampled ADC value and the reported power based on the first, second, third, and fourth relationships includes: Linearly fit K1_h and K2_h with the maximum gain and minimum gain, that is, take the minimum gain as the x-axis and K2_h as the y-axis as the first fitting point, take the maximum gain as the x-axis and K1_h as the y-axis as the second fitting point, and linearly fit the first fitting point and the second fitting point to obtain the slope factor K_h_factor. Linearly fit K1_l and K2_l with the maximum gain and minimum gain, that is, take the minimum gain as the x-axis and K2_l as the y-axis as the third fitting point, take the maximum gain as the x-axis and K1_l as the y-axis as the fourth fitting point, and linearly fit the third fitting point and the fourth fitting point to obtain the slope factor K_l_factor. Linearly fit B1_h and B2_h with the milliwatt values ​​corresponding to the maximum gain and the minimum gain, respectively. Specifically, use the milliwatt value corresponding to the minimum gain as the x-axis and B2_h as the y-axis as the fifth fitting point, and use the milliwatt value corresponding to the maximum gain as the x-axis and B1_h as the y-axis as the sixth fitting point. Linearly fit the fifth fitting point and the sixth fitting point to obtain the offset factor B_h_offset. Linearly fit B1_l and B2_l to the milliwatt values ​​corresponding to the maximum gain and the minimum gain, respectively. Specifically, use the milliwatt value corresponding to the minimum gain as the x-axis and B2_l as the y-axis as the seventh fitting point, and use the milliwatt value corresponding to the maximum gain as the x-axis and B1_l as the y-axis as the eighth fitting point. Linearly fit the seventh fitting point and the eighth fitting point to obtain the offset factor B_l_offset. The following values ​​are obtained respectively: reported power = K_h_factor×ADC+B_h_offset, reported power = K_h_factor×ADC+B_l_offset, reported power = K_l_factor×ADC+B_h_offset, and reported power = K_l_factor×ADC+B_l_offset, so as to obtain the relationship between the sampled ADC value of the input light and the reported power corresponding to each gain within the preset gain range.

8. The method for fast locking of different gains in an EDFA according to claim 7, characterized in that, The amplifier includes a digital potentiometer and a PID control circuit; The process of determining the target gain, obtaining the target gain factor, target ASE factor, and target reported power corresponding to the target gain, and obtaining the target input optical power based on the target gain factor, target ASE factor, and target reported power includes: For any target gain within the preset gain range, the PID control circuit acquires the target gain factor, target ASE factor, and target reported power corresponding to the target gain. The resistance value of the digital potentiometer is controlled by the target gain factor; The power of the target ASE factor is added to the target reported power to obtain the target input optical power.

9. The method for fast locking of different gains in an EDFA according to claim 8, characterized in that, The step of obtaining the required pump DAC value for the target gain based on the monitored output optical power and the target input optical power, and adjusting the drive current of the pump unit through the pump DAC value to lock the target gain, specifically involves: The target input optical power is used as the first input to the PID control circuit. The output optical power is used as the second input of the PID control circuit; The PID control circuit obtains a control error signal based on the difference between the first input and the second input; The control error signal serves as the input to the pump DAC. The digital potentiometer controls the drive current of the pump unit to obtain the required pump DAC value at the target gain. The signal is then used as the drive current to directly drive the pump unit to adjust the current, thereby locking the target gain.

10. A device for rapidly locking different gains of an EDFA, characterized in that, The device is used to implement the method for fast locking of different gains of EDFA as described in any one of claims 1-9, comprising: a gain factor fitting module, an ASE factor fitting module, an input light calibration module, an acquisition module, and a locking module; The gain factor fitting module is used to perform linear fitting on the calibration values ​​of the gain factors corresponding to the maximum and minimum gains within a preset gain range, so as to obtain the gain factors corresponding to each gain within the preset gain range. The ASE factor fitting module is used to perform linear fitting on the calibration values ​​of the ASE factors corresponding to the maximum and minimum gains within a preset gain range, so as to obtain the ASE factors corresponding to each gain within the preset gain range. The input light calibration module is used to calibrate the input light within the preset gain range to obtain the relationship between the sampled ADC value and the reported power of the input light corresponding to each gain within the preset gain range. The obtaining module is used to determine the target gain, obtain the target gain factor, target ASE factor and target reported power corresponding to the target gain, and obtain the target input optical power based on the target gain factor, target ASE factor and target reported power; The locking module is used to obtain the pump DAC value required for the target gain based on the monitored output optical power and the target input optical power, and adjust the drive current of the pump unit through the pump DAC value to lock the target gain.

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