CN104393479A - Laser full-life self-adaptive state control method - Google Patents
Laser full-life self-adaptive state control method Download PDFInfo
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- CN104393479A CN104393479A CN201410678328.9A CN201410678328A CN104393479A CN 104393479 A CN104393479 A CN 104393479A CN 201410678328 A CN201410678328 A CN 201410678328A CN 104393479 A CN104393479 A CN 104393479A
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Abstract
The invention discloses a laser life-cycle self-adaptive state control method, which comprises the following steps: parameter setting step: (11) detecting a saturation current value Is of the laser; (12) setting a maximum limit value Imax of the bias current; (13) setting a critical temperature value Tth; self-adaptive adjustment: (21) detecting the working current I of the laser and the working temperature T of the laser in real time; (22) comparing the magnitude relation between the working current I of the laser and the maximum limit value Imax of the bias current, and starting the APC circuit when I is less than Imax; and when the I is larger than or equal to Imax, comparing the magnitude relation between the working temperature T of the laser and the critical temperature Tth, and if the T is larger than or equal to the Tth, closing the APC circuit and starting the nonlinear control method. The control method of the invention overcomes the limitation of the APC circuit control on the whole performance constraint of the laser, and exploits the potential of the laser and the optical power can be made larger.
Description
Technical field
The invention belongs to field of laser device technology, specifically, relate to a kind of laser total life cycle self adaptation condition control method.
Background technology
Optical transmission module mainly comprises several parts such as drive circuit unit, single chip machine controlling circuit unit, optical assembly, external control circuit unit, signal of telecommunication input interface.The effect of driver (chip) circuit unit is to provide bias current and the modulated current of laser, thus realizes the electrical/optical conversion of digital signal.The major function of single chip machine controlling circuit unit controls driving chip, keeps normal condition (namely luminous power exports and also keep stable on certain power level) to make the Output optical power of laser.Export to make luminous power on certain power level, also keep stable, main employing at present, power control circuit, laser driver, laser, form feedback loop and come, thus make optical output power of laser be tending towards fixed value.The leading indicator utilizing emitted light power P of module and Extinction ratio, the bias current Ibias provided to laser primarily of driving chip and the threshold current Ith of modulated current Imod and laser and the Slop efficiency Se of P-I curve determines.When the ambient temperature of module work changes or long term device work aging after, the threshold current of laser and Slop efficiency can change, show as threshold current to increase and Slop efficiency reduction, in order to maintain the relative constancy of luminous power, the bias current Ibias that module applies to laser and modulated current Imod will increase, but the mode increasing bias current can not be passed through simply, because the operating state of laser is after entering saturation region, luminous power can reduce along with the increase of bias current, bias current acquires a certain degree even can damage laser.
In order to realize the protection to laser, common way is the maximum limit definite value by driver chip setting bias current, makes this maximum limit definite value be less than saturation current, as set maximum laser device bias current by an external sampling resistor.Because the performance of laser exists individual difference, the saturation current of laser is also not quite similar, in order to adapt to suitability for industrialized production needs, meet the protection demand of all lasers, that generally threshold limit value can be established is comparatively conservative, its value is far below actual saturation current value, the defect of this kind of mode is the overall performance sacrificing laser, it is too small that threshold limit value is arranged, limit giving full play to of laser performance, after laser works electric current reaches limit value, control circuit can cut out APC circuit suddenly, the luminous power of laser will be no longer controlled afterwards, laser works is in fixing bias current limit value, like this, along with the change of laser generates heat or ambient temperature, the luminous power of laser changes thereupon, can not ensure that communication is normal, and actual conditions are that laser completely can again by increasing the mode stabilized illumination power of bias current greatly, because also have certain adjustment space between its threshold limit value to its saturation current value.
Summary of the invention
The problem that the present invention can not fully work to solve existing laser in its total life cycle, proposes a kind of laser total life cycle self adaptation condition control method, can solve the problem.
In order to solve the problems of the technologies described above, the present invention is achieved by the following technical solutions:
A kind of laser total life cycle self adaptation condition control method, comprises the following steps:
Parameter setting step:
(11), the saturation current value Is of detection laser;
(12), the threshold limit value Imax of bias current, wherein Imax < Is are set;
(13), critical temperature value Tth is set;
Automatic adjusument step:
(21), detection laser operating current I, and laser. operating temperature T in real time;
(22), the magnitude relationship of the threshold limit value Imax of more described laser works electric current I and bias current, as I < Imax, open APC circuit, by described APC circuit, drive circuit for laser controlled;
As I >=Imax, the magnitude relationship of more described laser. operating temperature T and critical temperature value Tth, if T >=Tth, then closes APC circuit, enables nonlinear control method, directly control described drive circuit for laser by control unit.
Further, in described step (22), as I >=Imax and T < Tth time, if now control drive circuit for laser for APC circuit, then keep described APC circuit to open, still by described APC circuit, drive circuit for laser is controlled, if be now nonlinear control method, then open APC circuit, switch to APC circuit to control drive circuit for laser.
Further again, in described step (22), described APC circuit to the method that drive circuit for laser controls is:
The light that a1, PD photo-detector detection laser is launched, and light signal is converted to the signal of telecommunication;
The described signal of telecommunication is carried out amplification process by a2, amplifying circuit, and is sent to comparator and compares, and comparative result is sent to laser drive circuit;
If the described signal of telecommunication of a3 is less than default threshold value, then described drive circuit for laser increase is carried in the bias current on described laser, otherwise, reduce the bias current be carried on described laser.
Further, in described step (22), described nonlinear control method is:
B1, Real-Time Monitoring current lasers work temperature;
B2, from look-up table, search bias current Tb corresponding under current lasers work temperature;
B3, control laser drive current are carried on described laser with bias current Tb.
Further, in described step (11), the method for the saturation current value Is of detection laser is: from can opening the threshold bias current Ith of laser luminescence, bias current value is increased with step-length △ I, and the luminous power of corresponding detection laser luminescence, calculate luminous power growth rate corresponding when bias current often increases △ I, when growth rate equals zero, then current bias current value is saturation current value Is.
Compared with prior art, advantage of the present invention and good effect are: laser total life cycle self adaptation condition control method of the present invention, by Parameter setting step, and the saturation current value Is of detection laser, and the threshold limit value Imax of bias current is set according to saturation current value Is, unifiedly for the ease of industrial production again need not be set to fixing threshold limit value, the limit value arranged is different because of laser, can the performance of maximized performance laser, APC control circui is combined with nonlinear Control, suitable control mode is selected according to the operating state of laser, overcome the limitation to overall laser performance constraints that APC control circui brings on the one hand, excavate the potential of laser on the one hand in addition, luminous power can do more, working life extends greatly, the reliability of product has had larger raising, product can be applied among more severe special environment, the laser of common commercial level or technical grade specification can be used to develop meet the special light module product of specific demand.
After reading the detailed description of embodiment of the present invention by reference to the accompanying drawings, the other features and advantages of the invention will become clearly.
Accompanying drawing explanation
In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is (P-I) graph of relation of laser optical power and bias current in laser total life cycle self adaptation condition control method proposed by the invention.
Embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.
For current laser according to industrial production demand, need the maximum limit of bias current to set up put less to protect Laser Devices, and then sacrifice the overall performance of laser, cannot make laser in its total life cycle, give full play to the problem of its performance, propose a kind of laser total life cycle self adaptation condition control method, give the control mode of two kinds of lasers, this method is according to the magnitude relationship of real-time detection laser operating current I saturation current actual with it, the control mode of adaptively selected laser, the service behaviour in its lifetime can be played cmpletely, excavate the potential of laser, luminous power can do more, extend and be operated in APC(automated power and control) life-span of state laser, improve the adaptive capacity to environment of product.
Embodiment one, the present embodiment proposes a kind of laser total life cycle self adaptation condition control method, comprises the following steps:
Parameter setting step:
The saturation current value Is of S11, detection laser;
S12, the threshold limit value Imax of bias current is set, wherein Imax < Is;
S13, critical temperature value Tth is set;
Automatic adjusument step:
S21, detection laser operating current I, and laser. operating temperature T in real time;
The magnitude relationship of the threshold limit value Imax of S22, more described laser works electric current I and bias current, as I < Imax, opens APC circuit, is controlled by described APC circuit to drive circuit for laser;
As I >=Imax, the magnitude relationship of more described laser. operating temperature T and critical temperature value Tth, if T >=Tth, then closes APC circuit, enables nonlinear control method, directly control described drive circuit for laser by control unit.
As shown in Figure 1, for (P-I) relation curve of laser optical power and bias current, wherein, the saturation current value Is of laser for refer to that laser can export maximum luminous power time corresponding bias current value, the operating state of laser divides spontaneous emission district, stimulated emission linear work district, saturation region.When the bias current applied to laser is less than threshold current Ith, laser works is in spontaneous emission district, when bias current be greater than threshold current Ith be less than saturation current Is time, laser works is in linear zone, and luminous power can increase along with the increase of bias current; In saturation region, luminous power can reduce along with the increase of bias current.Therefore, current laser needs control to be operated in linear zone, because laser exists individual difference, its saturation current value Is is not quite similar, the product of the general same model of laser of the prior art or the product of different model are all set to the threshold limit value of the bias current of unified size, in order to ensure the normal of all lasers, it is less that the threshold limit value of general bias current is established, therefore the performance of laser is greatly sacrificed, also be, a lot of laser is in the very large bias current interval being greater than this threshold limit value, still linear modulation control can be carried out, but, due to the constraint of threshold limit value, its bias current can not exceed this threshold limit value again, therefore, the arrival life span that laser is just too early.The control method of the present embodiment solves the problems referred to above, carry out saturation current value Is respectively to each laser to detect, and the threshold limit value Imax of bias current is set according to its saturation current value Is, the limit value arranged is different because of laser, the maximum restriction Imax of its bias current arranged will the value of more existing setting larger, the work extending laser is linearly interval, can the performance of maximized performance laser, APC control circui is combined with nonlinear Control, suitable control mode is selected according to the operating state of laser, overcome the limitation to overall laser performance constraints that APC control circui brings on the one hand, the maximum electric current being greater than bias current no longer definitely can not be used for controlling, consider that temperature parameter is come in, due in the interval between Imax and Is, need according to current that what affect laser works performance most is its ambient temperature reason or himself senile cause, if the words that Current Temperatures is too high, the non-linear effects of temperature does leading, therefore nonlinear control method is adopted, if temperature is not too high, then remain and follow P-I curve, APC method is adopted to control, excavate the potential of laser, luminous power can do more, working life extends greatly, the reliability of product has had larger raising, product can be applied among more severe special environment, the laser of common commercial level or technical grade specification can be used to develop meet the special light module product of specific demand.
As a preferred embodiment, in described step S22, as I >=Imax and T < Tth time, if now control drive circuit for laser for APC circuit, then keep described APC circuit to open, still by described APC circuit, drive circuit for laser is controlled, if be now nonlinear control method, then open APC circuit, switch to APC circuit to control drive circuit for laser.Even if current laser status is bias current exceeded setting limit value, arrive as the principal element affecting laser performance if Current Temperatures is also unlikely to high, because still belong to stimulated emission linear work district in the Current Zone of Imax to Is, only power reduces gradually with the growth rate of electric current, but still can control, so continue to adopt APC Current Control, by the Function of laser to maximum.
In the present embodiment, in described step S22, described APC circuit to the method that drive circuit for laser controls is:
The light that a1, PD photo-detector detection laser is launched, and light signal is converted to the signal of telecommunication;
The described signal of telecommunication is carried out amplification process by a2, amplifying circuit, and is sent to comparator and compares, and comparative result is sent to laser drive circuit;
If the described signal of telecommunication of a3 is less than default threshold value, then described drive circuit for laser increase is carried in the bias current on described laser, otherwise, reduce the bias current be carried on described laser.
The core adopting APC control circui is exactly feedback control idea, the realization of function is by PD photo-detector, optical power control circuit, laser driver, the laser in laser assembly, form feedback loop to have come, thus make optical output power of laser be tending towards fixed value.Its FEEDBACK CONTROL basic process is when the Output optical power of LD reduces, and PD photoelectric current reduces, and the output current potential of amplifying circuit raises, then laser drive circuit bias current increases, and the Output optical power of LD is increased; Contrary then the luminous power of LD is reduced, thus reach automated power control action, make the Output optical power of LD keep stable.
In the present embodiment, in described step S22, described nonlinear control method is:
B1, Real-Time Monitoring current lasers work temperature;
B2, from look-up table, search bias current Tb corresponding under current lasers work temperature;
B3, control laser drive current are carried on described laser with bias current Tb.
Wherein, described look-up table writes in control program before laser dispatches from the factory, the performance number of bias current Tb corresponding when the working temperature of experiment detection laser and laser different operating temperature T and laser now, because now bias current and power are no longer linear, and temperature becomes the principal element affecting power, therefore, at known target power and when Current Temperatures being detected, find out the current bias current value that should modulate by look-up table, compensate for the defect that APC circuit linearity controls.
Further, in described step S11, the method for the saturation current value Is of detection laser is: from can opening the threshold bias current Ith of laser luminescence, bias current value is increased with step-length △ I, and the luminous power of corresponding detection laser luminescence, calculate luminous power growth rate corresponding when bias current often increases △ I, when growth rate equals zero, then current bias current value is saturation current value Is.
Certainly; above-mentioned explanation is not limitation of the present invention; the present invention is also not limited in above-mentioned citing, the change that those skilled in the art make in essential scope of the present invention, remodeling, interpolation or replacement, also should belong to protection scope of the present invention.
Claims (5)
1. a laser total life cycle self adaptation condition control method, is characterized in that, comprise the following steps:
Parameter setting step:
(11), the saturation current value Is of detection laser;
(12), the threshold limit value Imax of bias current, wherein Imax < Is are set;
(13), critical temperature value Tth is set;
Automatic adjusument step:
(21), detection laser operating current I, and laser. operating temperature T in real time;
(22), the magnitude relationship of the threshold limit value Imax of more described laser works electric current I and bias current, as I < Imax, open APC circuit, by described APC circuit, drive circuit for laser controlled;
As I >=Imax, the magnitude relationship of more described laser. operating temperature T and critical temperature value Tth, if T >=Tth, then closes APC circuit, enables nonlinear control method, directly control described drive circuit for laser by control unit.
2. laser total life cycle self adaptation condition control method according to claim 1, it is characterized in that, in described step (22), as I >=Imax and T < Tth time, if now control drive circuit for laser for APC circuit, then keep described APC circuit to open, still by described APC circuit, drive circuit for laser is controlled, if be now nonlinear control method, then open APC circuit, switch to APC circuit to control drive circuit for laser.
3. laser total life cycle self adaptation condition control method according to claim 1 and 2, is characterized in that, in described step (22), described APC circuit to the method that drive circuit for laser controls is:
The light that a1, PD photo-detector detection laser is launched, and light signal is converted to the signal of telecommunication;
The described signal of telecommunication is carried out amplification process by a2, amplifying circuit, and is sent to comparator and compares, and comparative result is sent to laser drive circuit;
If the described signal of telecommunication of a3 is less than default threshold value, then described drive circuit for laser increase is carried in the bias current on described laser, otherwise, reduce the bias current be carried on described laser.
4. laser total life cycle self adaptation condition control method according to claim 3, it is characterized in that, in described step (22), described nonlinear control method is:
B1, Real-Time Monitoring current lasers work temperature;
B2, from look-up table, search bias current Tb corresponding under current lasers work temperature;
B3, control laser drive current are carried on described laser with bias current Tb.
5. laser total life cycle self adaptation condition control method according to claim 4, it is characterized in that, in described step (11), the method for the saturation current value Is of detection laser is: from can opening the threshold bias current Ith of laser luminescence, bias current value is increased with step-length △ I, and the luminous power of corresponding detection laser luminescence, calculate luminous power growth rate corresponding when bias current often increases △ I, when growth rate equals zero, then current bias current value is saturation current value Is.
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Cited By (3)
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| CN111327368A (en) * | 2020-02-27 | 2020-06-23 | 长飞光纤光缆股份有限公司 | Control method and device for realizing rapid APC (automatic Power control) of optical module |
| CN112054850A (en) * | 2020-08-13 | 2020-12-08 | 深圳市普威技术有限公司 | Optical power adjusting method and device, storage medium and ONU (optical network Unit) equipment |
| CN112104424A (en) * | 2020-09-03 | 2020-12-18 | 南京捷澳德信息科技有限公司 | High-temperature extinction ratio optimization method for 5G forward-transmission industrial-grade optical module |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN107293938B (en) * | 2017-08-15 | 2019-11-08 | 中航海信光电技术有限公司 | Method and system for prolonging service life of laser for optical module |
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