Method and device for inhibiting laser wavelength temperature drift

Abstract

The invention discloses a method and a device for inhibiting laser wavelength temperature drift, relates to laser wavelength measurement and laser frequency stabilization, and belongs to the field of atomic physics and quantum optics. The device comprises a laser output light unit, a high-precision wavemeter monitoring unit and a temperature drift feedback control unit. And measuring a wavelength drift coefficient a of environment temperature T environment-laser wavelength lambda. Measuring a set temperature Tset-laser wavelength lambda and a wavelength control coefficient b; and according to the measured coefficients a and b, calculating to obtain a temperature gradient compensation coefficient c (c = a / b). When the laser works normally, the T environment is collected in real time, and the set temperature Tset of the laser is changed according to the temperature gradient compensation coefficient c and the T environment, so that the laser wavelength temperature drift is inhibited. According to the invention, active suppression of laser wavelength temperature drift is realized by regulating and controlling a temperature gradient compensation coefficient. The device has the advantages of being simple in structure, high in wavelength drift suppression capability, low in energy loss and the like.

Description

Technical Field

[0001] The invention discloses a method and a device for suppressing laser wavelength temperature drift, relates to laser wavelength measurement and laser frequency stabilization, and belongs to the fields of atomic physics and quantum optics. Background Art

[0002] With the rapid development of laser technology, semiconductor lasers, fiber lasers, etc. are currently widely used in military and defense fields such as atomic physics. For quantum precision measuring instruments such as atomic gravimeters, the performance of the laser largely determines the operating temperature range. At different temperatures, the electrical parameters of the laser's internal materials and the refractive index of light will change, resulting in wavelength drift. This wavelength drift is a problem that cannot be ignored for systems that require precise wavelength control, so it is often necessary to manage and optimize it through appropriate temperature control measures.

[0003] Although high-performance lasers usually have a temperature control module to maintain the temperature stability of the laser and suppress the influence of the ambient temperature, they are limited by factors such as the temperature control structure scheme, laser size, and laser packaging structure. When the ambient temperature changes, the difference between the ambient temperature and the laser setting temperature causes the actual temperature of the laser to change with the ambient temperature, resulting in a "temperature gradient" phenomenon (the greater the temperature difference, the more the actual temperature of the laser deviates from the setting temperature), resulting in significant residual laser wavelength drift, which has an immeasurable impact on the stability of the laser frequency. The main solution to reduce the influence of ambient temperature on the wavelength stability of the laser is the multi-layer temperature control structure scheme, which often uses a semiconductor cooler (TEC) to maintain the stability of the laser at the operating temperature, which helps to reduce the performance fluctuations caused by temperature changes, but the disadvantage is that the power consumption is large and the temperature control system structure is complex. Therefore, it is urgent to develop a simple and easy method to suppress the laser wavelength temperature drift effect. Summary of the invention

[0004] In order to solve the shortcomings of current lasers, such as the wavelength being easily affected by changes in ambient temperature and the unstable output laser frequency, and to meet the demand for autonomous temperature control of the laser, the purpose of the present invention is to provide a method and device for suppressing laser wavelength temperature drift, and to achieve active suppression of laser wavelength temperature drift by adjusting the temperature gradient compensation coefficient. The present invention has the advantages of simple device structure, strong wavelength drift suppression capability, and low energy loss.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] The present invention discloses a method for suppressing laser wavelength temperature drift, comprising the following steps:

[0007] Step 1: Measure the ambient temperature T 环境 , laser wavelength λ波长 and drift coefficient a;

[0008] Place the laser in a high and low temperature box, keep the laser setting temperature unchanged, change the temperature of the high and low temperature box, and simulate the ambient temperature T 环境 Changes, while using a high-precision wavelength meter to collect the ambient temperature λ in real time 波长 Changes in the high and low temperature box ambient temperature T 环境 -Laser wavelength λ 波长 The data were linearly fitted, and the slope was the drift coefficient a;

[0009] Step 2: Measure and set the temperature T set , laser wavelength λ 波长 And control coefficient b.

[0010] At ambient temperature T 环境 Under the same conditions, change the laser setting temperature T set , and use a high-precision wavelength meter to measure the corresponding laser wavelength λ 波长 Changes, to the set temperature T set -Laser wavelength λ 波长 The data were linearly fitted, and the slope was the control coefficient b;

[0011] Step 3: Measure the temperature gradient compensation coefficient c;

[0012] According to the drift coefficient a obtained in step 1 and the control coefficient b obtained in step 2, the temperature gradient compensation coefficient c is calculated by the formula c=a / b;

[0013] Step 4: Change T set , make the wavelength the resonant wavelength of the target value, collect the ambient temperature T 环境 , at this time T 环境 =T set , the temperature at this time is assumed to be the reference temperature T0.

[0014] Step 5: The laser works normally and the ambient temperature T is collected in real time 环境 , according to the temperature gradient compensation coefficient c and T 环境 , real-time change of laser setting temperature T set , according to formula T set =T0+c*(T 环境 -T0) to suppress the temperature drift of laser wavelength.

[0015] Preferably, the laser wavelength temperature drift can be suppressed by more than 10 times.

[0016] The present invention also discloses a device for suppressing laser wavelength temperature drift, which is used to implement the method for suppressing laser wavelength temperature drift. A device for suppressing laser wavelength temperature drift includes a laser output light unit, a high-precision wavelength meter monitoring unit and a temperature drift feedback control unit. The laser output unit outputs a laser for testing. The laser light output port of the laser output unit is connected to a high-precision wavelength meter. The high-precision wavelength meter monitoring unit is used to monitor the laser wavelength change in real time. The temperature drift feedback control unit, the laser is placed in a high-low temperature box, the temperature of the high-low temperature box is changed, the ambient temperature change is simulated, and the laser setting temperature is changed in real time through the temperature compensation coefficient and the ambient temperature, so as to suppress the laser wavelength temperature drift.

[0017] Beneficial effects:

[0018] 1. The present invention discloses a method and device for suppressing laser wavelength temperature drift, which does not require a complex temperature control structure. It only needs to measure the ambient temperature and change the set temperature of the laser seed in real time according to the temperature compensation coefficient, so as to suppress the laser wavelength temperature drift.

[0019] 2. The present invention discloses a method and device for suppressing laser wavelength temperature drift. By measuring the drift coefficient and the control coefficient, the temperature gradient compensation coefficient is calculated to achieve active suppression of laser wavelength temperature drift. The suppression effect is good. The laser wavelength temperature drift can be suppressed by more than 10 times by this method, and the suppression capability is greatly improved.

[0020] 3. The method and device for suppressing laser wavelength temperature drift disclosed in the present invention are applicable to a variety of lasers, including fiber lasers, semiconductor lasers, etc., and have a wider range of application scenarios compared to specific laser output systems.

[0021] 4. The method and device for suppressing laser wavelength temperature drift disclosed in the present invention is a method with an advance prediction feature. Compared with the large and complex system of the traditional temperature control system, it can make control responses in advance according to different laser systems and different background environments, thereby achieving a fast, efficient, simple and easy suppression effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A flow chart of a method for suppressing laser wavelength temperature drift disclosed in the present invention;

[0023] Figure 2 A module diagram of a device for suppressing laser wavelength temperature drift disclosed in the present invention;

[0024] Figure 3 This is a comparison chart of the inhibitory effects of the embodiments provided by the present invention. DETAILED DESCRIPTION

[0025] In order to better illustrate the purpose and advantages of the present invention, the invention is further described below with reference to the accompanying drawings and examples.

[0026] Embodiment 1:

[0027] Due to the positional deviation between the temperature sensor in the laser and the main components inside the laser, a "temperature gradient" phenomenon will occur. The greater the temperature difference, the more the actual temperature of the laser deviates from the set temperature, resulting in significant residual laser wavelength drift.

[0028] like Figure 1 As shown, this embodiment discloses a method and device for suppressing laser wavelength temperature drift, the method comprising the following steps:

[0029] S101: Measure ambient temperature T 环境 -Laser wavelength λ 波长 Drift coefficient a;

[0030] First, place the fiber laser in a high and low temperature box. Keep the laser setting temperature unchanged and change the temperature of the high and low temperature box. The temperature operating range is (-20~50)℃. Simulate T 环境 changes, and uses a high-precision wavelength meter to collect λ in real time 波长 Change 1.5GHz (usually convert wavelength units into frequency units to express the degree of drift), high and low temperature box temperature T 环境 -Laser wavelength λ 波长 The data is linearly fitted, and the slope is the drift coefficient a. The data points (-20°C, 384.226651) and (25°C, 384.228256) are taken for calculation, which is approximately equal to T 环境 For every 1°C increase in temperature, the wavelength increases by 35.7MHz, so a=35.7MHz.

[0031] S102: Measure the set temperature T set -Laser wavelength λ 波长 Control coefficient b;

[0032] Then in T 环境 Under the same conditions, change the laser setting temperature T set , set the temperature range to (-5~30)℃, and use a high-precision wavelength meter to measure the corresponding λ 波长 Change 4.5GHz, set temperature T set -Laser wavelength λ 波长 The data is linearly fitted, and the slope is the control coefficient b. The data points (21°C, 384.240507THz) and (22°C, 384.236005THz) are taken for calculation, which is approximately equal to T setFor every 0.1°C increase in temperature, the wavelength decreases by 450MHz, so b=-450MHz.

[0033] S103: According to the measured coefficients a and b, the temperature gradient compensation coefficient c can be obtained by calculation: c = a / b = 35.7 MHz / (-4500 MHz) ≈ -0.00793.

[0034] S104: Then change the laser T set The temperature is 22.16℃, and the wavelength is set to the target value, the resonance wavelength of the repump light is 384.235087THz. The T 环境 is 22℃, that is, T 环境 =T set , the default temperature at this time is the reference temperature T0. (T0 is T 环境 With T set When the laser frequency is the target value, the temperature is a constant.)

[0035] S105: Finally, the laser works normally and collects T in real time 环境 , according to the temperature gradient compensation coefficient c, the laser setting temperature T is changed in real time set , T set =T0+c*(T 环境 -T0). The temperature sensor collects T 环境 =25.44℃, then the temperature rises by 3.28℃ relative to the reference temperature, that is, T set =T0+c*(T 环境 -T0)=22.16-0.00793*(25.44-22.16)≈22.134°C, so setting the laser seed temperature to 22.134°C can achieve wavelength drift suppression when the ambient temperature is 25.44°C.

[0036] like Figure 2 As shown, the present embodiment discloses a device for suppressing laser wavelength temperature drift, comprising a laser output unit 10, a high-precision wavelength meter monitoring unit 20 and a temperature drift feedback control unit 30. The laser output unit 10, the normal laser light output is used for testing; the high-precision wavelength meter monitoring unit 20, the laser light output port is connected to the high-precision wavelength meter, used to monitor the laser wavelength change in real time; the temperature drift feedback control unit 30, the laser is placed in a high-low temperature box, the high-low temperature box temperature is changed, the ambient temperature change is simulated, and the laser setting temperature is changed in real time through the temperature compensation coefficient and the ambient temperature, so as to suppress the laser wavelength temperature drift.

[0037] like Figure 3As shown, the blue curve is the wavelength drift in the temperature range of (-20~50)℃ before the laser wavelength temperature drift is suppressed, which is approximately equal to 2.5GHz, corresponding to a temperature change of 1℃, and a wavelength drift of 36MHz; the red curve is the wavelength drift in the temperature range of (-5~30)℃ after the laser wavelength temperature drift is suppressed, which is approximately equal to 150MHz, corresponding to a temperature change of 1℃, and a wavelength drift of 2.5MHz. Therefore, the specific embodiment of the method can achieve a laser wavelength temperature drift suppression of 14.4 times, and the suppression capability is greatly improved.

[0038] In the embodiments provided in the present application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the system embodiments described above are only schematic, such as the division of units, which can be a logical function division, and there can be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple units. Some or all of the units can be selected according to actual needs to achieve the purpose of the scheme of this embodiment.

[0039] The specific description above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for suppressing laser wavelength temperature drift, characterized in that: The following steps are included: Step 1: Measure the ambient temperature T 环境 , laser wavelength λ 波长 and drift coefficient a; Place the laser in a high and low temperature box, keep the laser setting temperature unchanged, change the temperature of the high and low temperature box, and simulate the ambient temperature T 环境 Changes, while using a high-precision wavelength meter to collect the ambient temperature λ in real time 波长 Changes in the high and low temperature box ambient temperature T 环境 -Laser wavelength λ 波长 The data were linearly fitted, and the slope was the drift coefficient a; Step 2: Measure and set the temperature T set , laser wavelength λ 波长 and control coefficient b; At ambient temperature T 环境 Under the same conditions, change the laser setting temperature T set , and use a high-precision wavelength meter to measure the corresponding laser wavelength λ 波长 Changes, to the set temperature T set -Laser wavelength λ 波长 The data were linearly fitted, and the slope was the control coefficient b; Step 3: Measure the temperature gradient compensation coefficient c; According to the drift coefficient a obtained in step 1 and the control coefficient b obtained in step 2, the temperature gradient compensation coefficient c is calculated by the formula c=a / b; Step 4: Change T set , make the wavelength the resonant wavelength of the target value, collect the ambient temperature T 环境 , at this time T 环境 =T set , then the temperature at this time is assumed to be the reference temperature T0; Step 5: The laser works normally and the ambient temperature T is collected in real time 环境 , according to the temperature gradient compensation coefficient c and T 环境 , real-time change of laser setting temperature T set , according to formula T set =T0+c*(T 环境 -T0) to suppress the temperature drift of laser wavelength.

2. A method for suppressing laser wavelength temperature drift according to claim 1, characterized in that: The laser wavelength temperature drift is suppressed by more than 10 times.

3. A device for suppressing laser wavelength temperature drift, used to implement the method according to claim 1, characterized in that: It includes a laser output light unit, a high-precision wavelength meter monitoring unit and a temperature drift feedback control unit; a laser output unit outputs laser light for testing; a laser light output port of the laser output unit is connected to the high-precision wavelength meter; The high-precision wavelength meter monitoring unit is used to monitor the laser wavelength changes in real time. The temperature drift feedback control unit places the laser in a high and low temperature box, changes the temperature of the high and low temperature box, simulates the ambient temperature changes, and changes the laser setting temperature in real time through the temperature compensation coefficient and the ambient temperature to suppress the laser wavelength temperature drift.

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