CN109724775B - Optical module open loop life compensation method and system - Google Patents

Optical module open loop life compensation method and system Download PDF

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CN109724775B
CN109724775B CN201711033903.XA CN201711033903A CN109724775B CN 109724775 B CN109724775 B CN 109724775B CN 201711033903 A CN201711033903 A CN 201711033903A CN 109724775 B CN109724775 B CN 109724775B
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laser
aging
current
time
compensation
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CN109724775A (en
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韩泽
王成伟
王海山
谭先友
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Hisense&jonhon Optical Electrical Technologies Co ltd
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Abstract

The invention discloses an optical module open loop life compensation method and system, wherein the aging slope of a laser is obtained based on aging data fitting; based on aging modelObtaining an acceleration factor; obtaining the threshold current and the slope efficiency of the laser at any time when the laser is in use based on the aging slope and the acceleration factor; obtaining an aging coefficient based on the threshold current, the skew efficiency, the initial threshold current of the laser and the initial skew efficiency of the laser at any time; and determining a compensation bias current for driving the laser based on the aging coefficient so as to realize the laser life compensation. The aging coefficient is quantized by means of threshold current and skew efficiency of the laser in the optical module, service life compensation of the optical module is performed by quantized data, and the method can be used for accurate real-time evaluation of the reliability of a photoelectric product by a PHM system.

Description

Optical module open loop life compensation method and system
Technical Field
The invention belongs to the technical field of optical communication, and particularly relates to an optical module open loop service life compensation method and system.
Background
The laser is a main core device of the parallel optical module, and the failure modes of the laser are mainly divided into three forms, namely an early failure mode, an accidental failure mode and a loss failure mode. The three modes occur at different time periods.
Among other things, the loss failure mode is an irreversible process, so that there is an effective life cycle for the light module. In the field of civil optical modules, the requirement on the service life of an optical module is not high due to the characteristic of fast update, but in the field of special optical modules, the problem of service life compensation of the optical module is particularly prominent because the special optical module needs to continuously work in a severe environment and is not easy to replace.
The life compensation method can be adopted to compensate the laser loss to achieve the effect of prolonging the service life of the laser. In the prior art, the laser service life compensation method mainly has two types: a closed loop life compensation method and an open loop life compensation method. In the laser closed-loop service life compensation method, the backlight current of a laser is monitored in real time, the magnitude of the driving current is adjusted in real time according to the magnitude of the backlight current, and the stability of the current in the laser is ensured in real time; the closed-loop control can be completed by a special driving chip, but most of the chips are single-channel chips, are only suitable for single-channel optical modules and cannot be suitable for parallel optical modules, and the chips used by the optical modules with the closed-loop control have relatively high cost and are not suitable for large-scale use. The laser open-loop life compensation method mainly aims at temperature compensation for preventing output optical power change and eye pattern degradation caused by temperature influence of a device, and does not consider the problem of life compensation caused by the increase of the service time of a module.
Disclosure of Invention
The application provides an optical module open loop life compensation method and system, which are used for realizing parallel optical module open loop life compensation.
In order to solve the technical problems, the application adopts the following technical scheme:
an optical module open loop life compensation method is provided, which comprises the following steps: obtaining aging slope of laser based on aging data fitting(ii) a The aging data comprises laser working current and laser working temperature which are obtained in aging setting time under the conditions of setting aging temperature and setting aging current; based on aging modelObtaining an acceleration factor; wherein, theFor the aged operating current, theFor the use of the laser operating current, theTo activate the energy parameter, saidFor the ageing operating temperature of the laser, theK is a constant value for the operating temperature of the laser; based on the aging slopeAnd said acceleration factor A is such that the threshold current of said laser at any time during use is obtainedAnd skew efficiency SE; based on the threshold current at any timeObtaining an aging coefficient by the skew efficiency SE, the initial threshold current of the laser and the initial skew efficiency of the laser; determining a compensation bias current to drive the laser based on the aging factor to achieve compensation for the laser lifetime.
An optical module open loop life compensation system is provided, which comprises a driving chip and a laser; the device comprises an aging slope determining unit, an acceleration factor determining unit, a threshold current and slope efficiency determining unit, an aging system determining unit and a compensation bias current determining unit; the aging slope determining unit is used for obtaining the aging slope of the laser device based on aging data fitting(ii) a The aging data comprises laser working current and laser working temperature which are obtained in aging setting time under the conditions of setting aging temperature and setting aging current; the acceleration factor determining unit is used for determining the acceleration factor based on an aging modelObtaining an acceleration factor; wherein, theFor the aged operating current, theFor the use of the laser operating current, theTo activate the energy parameter, saidFor the ageing operating temperature of the laser, theIs the operating temperature of the laser; the threshold current and slope efficiency determination unit is used for determining the aging slopeAnd said acceleration factor A is such that the threshold current of said laser at any time during use is obtainedAnd skew efficiency SE; the aging coefficient determining unit is used for determining the aging coefficient based on the threshold current at any timeObtaining an aging coefficient by the skew efficiency SE, the initial threshold current of the laser and the initial skew efficiency of the laser; the compensation bias current determining unitAnd the compensation bias current is used for determining the compensation bias current written into the driving chip based on the aging coefficient so as to realize the service life compensation of the laser.
Compared with the prior art, the application has the advantages and positive effects that: according to the method and the system for compensating the open loop life of the optical module, aging data in an accelerated aging experiment of a laser is used as a data sample, an aging coefficient of aging generated in the use of the laser is simulated, the magnitude of bias current to be compensated for the laser is determined according to the aging coefficient of the laser, namely, the aging condition of the laser is combined, and the compensation bias current is used for driving the optical module so as to maintain the optical power of emitted light of the laser to be kept from falling at any time point, so that the open loop life of the laser is compensated, and the service life of the laser is prolonged. The aging coefficient obtained in the application can also be used for state detection, state evaluation, fault prediction, guarantee decision and the like of the laser, so that the reliability of the photoelectric product can be accurately evaluated in real time.
Other features and advantages of the present application will become more apparent from the detailed description of the embodiments of the present application when taken in conjunction with the accompanying drawings.
Drawings
Fig. 1 is a flowchart of a method for compensating an open loop life of an optical module according to the present application;
fig. 2 is a system block diagram of an optical module open-loop life compensation system proposed in the present application;
FIG. 3 is a graph of an aging slope fit in the present application.
Detailed Description
The following describes embodiments of the present application in further detail with reference to the accompanying drawings.
The optical module open loop life compensation method provided by the application can be applied to open loop life compensation of lasers of a multi-path parallel optical module, and performance indexes are improved, as shown in fig. 1, the method comprises the following steps:
step S11: obtaining aging slope of laser based on aging data fitting
According to the method, an aging test is adopted to accelerate the simulation of the working state of the optical module, the setting time of the optical module is aged under the conditions of setting the aging temperature and setting the aging current, and the aging data of the working of the optical module in the aging process are collected, including but not limited to the working current of a laser, the working temperature of the laser and the like, as shown in FIG. 3, the aging slope of the laser of the optical module is obtained through linear fitting according to the aging data, wherein the ordinate represents the output optical power (dBm) of the laser, the abscissa represents the time (h), and as can be seen from the figure, the laser is subjected to an aging test for 1500 hours, and the aging slope obtained through fitting is-0..
Step S12: based on aging modelAn acceleration factor is obtained.
In the application, from the angle of quantization, the aging coefficient of the laser is qualitatively and quantitatively analyzed, the real-time index of the laser is monitored, and the service life of the optical module is compensated by quantized data.
The main purpose of obtaining the acceleration factor is to obtain the equivalent time of the optical module working in the use environment (temperature and working current) of the user by using the aging experimental data and the aging model.
Wherein the content of the first and second substances,for the aging operating current of the laser in the aging experiment,for the user to use the operating current when using the laser,in order to activate the energy parameter(s),for the aging operating temperature of the laser in the aging experiment, the operating temperature of the laser used by the user, k is the Boltzmann constant, which is 8.618(ii) a Wherein the content of the first and second substances,according to different laser failure modes (wear _ out _ mode, random _ mode), different values are adopted to carry out calculation, and the values are shown in the following table.
Watch 1
Device Wear_out_mode(Ea) Random_mode(Ea)
Laser Diodes 0.4eV 0.35eV
Laser Modules 0.4eV 0.35eV
LEDS 0.5eV 0.35eV
LED modules 0.5eV 0.35eV
photoDiodes 0.7eV 0.35eV
Detector modules 0.7eV 0.35eV
Receiver Modules 0.7eV 0.35eV
EA Modulators 0.4eV 0.35eV
External Modulators 0.7eV 0.35eV
Step S13: based on aging slopeAnd acceleration factor A to obtain the threshold current of the laser at any time during useAnd skew efficiency SE.
Based on=Obtaining the threshold current of the laser at any time in use(ii) a And, based on SE =Obtaining the skew efficiency SE of the laser at any time when the laser is in use; among them, in the above-mentioned case,is the initial threshold current of the laser and,for the initial ramp efficiency of the laser,is a time point corresponding to any time,is the working current of the laser at any time.
When the current of the laser is small, the optical power output by the laser is basically not output, but the optical power is still not output along with the increase of the current, when the current is increased to a certain value, the output begins to appear, and the optical power is linearly increased along with the increase of the current, and the current at the moment is called the threshold current of the laser; the threshold current is related to the material and structure of the optical module laser, and changes with the use loss of the optical module. For laser diodes, the smaller the threshold current, the better, typically at 25 ℃, the threshold current of VCSEL-LC is at 02 ° -2 mA. The tilt efficiency of a laser of a parallel optical module refers to the ratio of the output optical power of the laser to the input current.
Initial threshold current of laserAnd initial skew efficiencyThe method can be determined by adopting a straight line fitting method, a secondary fitting method and a secondary derivation method.
Step S14: based on threshold current at any timeThe skew efficiency SE, the initial threshold current of the laser and the initial skew efficiency of the laser yield an aging factor.
The invention aims to maintain the output light power of the laser to be constant at any time point, thereby realizing the compensation of the service life of the laser. For this purpose, the formula of output is based on the optical power at the initial timeAnd output optical power formula at any time pointIf the output light power of the laser is kept unchanged, establishing a formula for solving the aging coefficient as follows:wherein, in the step (A),is the initial threshold current of the laser and,for the initial ramp efficiency of the laser,is the working current of the laser at any time.
Step S15: and determining a compensation bias current for driving the laser based on the aging coefficient so as to realize the laser life compensation.
Based onObtaining a compensating bias current(ii) a Wherein the content of the first and second substances,the working current of the laser at any time, and X is an aging system.
The compensation bias current is written into the driving chip, the driving chip drives the laser to work according to the compensation bias current, the compensation bias current obtained according to the steps is an analog value and needs to be digitized and then transmitted to the driving chip, namely, a step of converting the analog current into digital current exists, and the analog compensation bias current is converted into digital quantity by adopting the following formula by taking an HXT6112 chip produced by Gigoptix company as an example:wherein, the water-soluble polymer is a polymer,is the number of 40, and the weight of the product,when the digital quantity is 0.25, the change of the current analog quantity caused by 1 change of the digital quantity is 40X0.25/48=0.21mA, and when the required current value is 7mA, the digital quantity to be written into the driver chip is 7/0.21= 33.7.
According to the lifetime compensation method provided by the application, after 10 years, the threshold current of a laser is 0.589mA and the ramp efficiency of the laser is 0.393, the aging coefficient obtained by solving is 0.08, and the bias current required to be compensated is 6X (1+0.08) =6.48 mA.
Based on the proposed optical module open-loop life compensation method, the present application further proposes an optical module open-loop life compensation system, as shown in fig. 2, including a driving chip 21, a laser 22, an aging slope determining unit 23, an acceleration factor determining unit 24, a threshold current and slope efficiency determining unit 25, an aging system determining unit 26, and a compensation bias current determining unit 27.
The aging slope determination unit 23 is used for determining the aging numberObtaining the aging slope of the laser 21 according to the fitting(ii) a The aging data comprises laser aging working current and laser aging working temperature which are obtained in aging setting time under the conditions of setting aging temperature and setting aging current; the acceleration factor determination unit 24 is adapted to determine the acceleration factor based on an aging modelObtaining an acceleration factor; wherein the content of the first and second substances,in order to age the operating current,for the use of the operating current of the laser,in order to activate the energy parameter(s),in order to age the operating temperature of the laser,the working temperature of the laser; the threshold current and ramp efficiency determination unit 25 is adapted to determine the aging slopeAnd acceleration factor A to obtain the threshold current of the laser 21 at any time during useAnd skew efficiency SE; the aging factor determination unit 26 is used for determining the aging factor based on the threshold current at any timeSlope efficiency SE, initial threshold current of the laser and initial threshold current of the laserObtaining an aging coefficient by the skew efficiency; the compensation bias current determination unit 27 is used for determining the compensation bias current written into the driving chip 22 based on the aging coefficient so as to realize the laser life compensation.
Wherein the threshold current and skew efficiency determination unit 25 is specifically configured to determine the threshold current and skew efficiency based on=Obtaining the threshold current of the laser at any time in use(ii) a Based on SE =Obtaining the skew efficiency SE of the laser at any time when the laser is in use; wherein the content of the first and second substances,is the initial threshold current of the laser and,for the initial ramp efficiency of the laser,is a time point corresponding to any time,is the working current of the laser at any time.
The aging factor determination unit 26 is specifically configured to determine the aging factor based onObtaining an aging coefficient; wherein the content of the first and second substances,is the initial threshold current of the laser and,for the initial ramp efficiency of the laser,is the working current of the laser at any time.
The compensation bias current determination unit 27 is specifically configured to determine the offset based onThe reverse compensation bias current of (1); wherein the content of the first and second substances,the working current of the laser at any time, and X is an aging system.
The working method of the optical module open loop life compensation system has been described in detail in the above optical module open loop life compensation method, and is not described herein again.
The optical module open-loop life compensation method and System provided by the application aim to maintain the output optical power of a laser not to fall off at any time point, quantize the aging coefficient by means of the threshold current and the slope efficiency of the laser in the optical module, perform life compensation of the optical module by quantized data, and can also be used in a PHM (physics and System Health management) System for state detection, state evaluation, fault prediction, guarantee decision and the like, so as to complete accurate real-time evaluation of the reliability of a photoelectric product.
It should be noted that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art should also make changes, modifications, additions or substitutions within the spirit and scope of the present invention.

Claims (6)

1. An optical module open loop life compensation method, comprising:
obtaining aging slope of laser based on aging data fitting(ii) a The aging data comprises laser working current and laser working temperature which are obtained in aging setting time under the conditions of setting aging temperature and setting aging current;
based on aging modelObtaining an acceleration factor; wherein, theFor aging the operating current, saidFor the use of the laser operating current, theTo activate the energy parameter, saidFor the ageing operating temperature of the laser, theK is a constant value for the operating temperature of the laser;
based on the aging slopeAnd said acceleration factor A is such that the threshold current of said laser at any time during use is obtainedAnd skew efficiency SE;
based on the threshold current at any timeObtaining an aging coefficient by the skew efficiency SE, the initial threshold current of the laser and the initial skew efficiency of the laser;
determining a compensation bias current for driving the laser based on the aging coefficient to achieve compensation for the laser lifetime;
wherein the aging slope is based onAnd said acceleration factor A is such that the threshold current of said laser at any time during use is obtainedAnd skew efficiency SE, specifically:
based on=Obtaining the threshold current of the laser at any time during use
Based on SE =Obtaining the skew efficiency SE of the laser at any time when the laser is in use;
wherein the content of the first and second substances,is the initial threshold current of the laser,for the initial skew efficiency of the laser,is the time point corresponding to the arbitrary time,the working current of the laser at any time is shown.
2. The method for compensating for the open loop lifetime of an optical module according to claim 1, wherein the threshold current is based on the arbitrary timeObtaining an aging coefficient by the skew efficiency SE, the initial threshold current of the laser and the initial skew efficiency of the laser, specifically:
based onObtaining the aging coefficient;
wherein the content of the first and second substances,is the initial threshold current of the laser,for the initial skew efficiency of the laser,the working current of the laser at any time is shown.
3. The optical module open loop life compensation method according to claim 1, wherein a compensation bias current for driving the laser is determined based on the aging coefficient, specifically:
based onObtaining the compensation biasPlacing current;
wherein the content of the first and second substances,and X is the working current of the laser at any moment and is the aging coefficient.
4. The optical module open loop life compensation system comprises a driving chip and a laser; the device is characterized by comprising an aging slope determining unit, an acceleration factor determining unit, a threshold current and slope efficiency determining unit, an aging coefficient determining unit and a compensation bias current determining unit;
the aging slope determining unit is used for obtaining the aging slope of the laser device based on aging data fitting(ii) a The aging data comprises laser working current and laser working temperature which are obtained in aging setting time under the conditions of setting aging temperature and setting aging current;
the acceleration factor determining unit is used for determining the acceleration factor based on an aging modelObtaining an acceleration factor; wherein, theFor aging the operating current, saidFor the use of the laser operating current, theTo activate the energy parameter, saidFor the ageing operating temperature of the laser, theIs the operating temperature of the laser;
the threshold current and slope efficiency determination unit is used for determining the aging slopeAnd said acceleration factor A is such that the threshold current of said laser at any time during use is obtainedAnd skew efficiency SE;
the aging coefficient determining unit is used for determining the aging coefficient based on the threshold current at any timeObtaining an aging coefficient by the skew efficiency SE, the initial threshold current of the laser and the initial skew efficiency of the laser;
the compensation bias current determining unit is used for determining the compensation bias current written into the driving chip based on the aging coefficient so as to realize the service life compensation of the laser;
wherein the threshold current and skew efficiency determination unit is particularly for
Based on=Obtaining the threshold current of the laser at any time during use
Based on SE =Obtaining the skew efficiency SE of the laser at any time when the laser is in use;
wherein the content of the first and second substances,is the initial threshold current of the laser,for the initial skew efficiency of the laser,is the time point corresponding to the arbitrary time,the working current of the laser at any time is shown.
5. Optical module open loop life compensation system according to claim 4, characterized in that the aging factor determination unit is specifically configured for
Based onObtaining the aging coefficient;
wherein the content of the first and second substances,is the initial threshold current of the laser,for the initial skew efficiency of the laser,the working current of the laser at any time is shown.
6. Optical module open loop life compensation system according to claim 4, characterized in that the compensation bias current determination unit, in particular for
Based onThe compensation bias current of (a);
wherein the content of the first and second substances,and X is the working current of the laser at any moment and is the aging coefficient.
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