A real-time detection method for laser temperature

Abstract

The present invention relates to the field of laser temperature measurement technology, and discloses a real-time detection method for laser temperature, comprising obtaining a first light intensity of the laser emitted by the laser to be tested after passing through a gasless gas pool; obtaining a second light intensity of the laser emitted by the laser to be tested after passing through a gas pool filled with a known concentration of absorbing gas; determining the line intensity of the laser emitted by the laser to be tested according to the obtained first light intensity and second light intensity; determining the wavelength of the laser emitted by the laser to be tested according to the line intensity of the laser emitted by the laser to be tested; and determining the current operating temperature of the laser to be tested according to the wavelength of the laser emitted by the laser to be tested. The present invention can improve the real-time and accuracy of laser temperature detection.

Description

Technical Field

[0001] The invention relates to the technical field of laser temperature measurement, and in particular to a real-time detection method for laser temperature. Background Art

[0002] Semiconductor lasers are core components in optical communication systems, and the operating temperature of semiconductor lasers will have a significant impact on their communication performance. When the operating temperature of a semiconductor laser changes, its slope efficiency will change, causing its emitted light power to change with the operating temperature. If the change in optical power caused by temperature changes is unpredictable, the power change will become part of the system signal noise, causing the system communication performance to deteriorate. To avoid the above problems, it is necessary to accurately control the working problems of semiconductor lasers. The premise of precise temperature control is to accurately measure the current operating temperature of the semiconductor laser.

[0003] The existing semiconductor laser temperature measurement solution is to integrate a thermistor inside the package of the laser being measured. The thermistor is usually placed on the same ceramic substrate as the laser chip being measured. The temperature of the thermistor is calculated by measuring the resistance of the thermistor, thereby obtaining the temperature of the laser. However, since it takes a certain amount of time for heat to be transferred from the laser to the thermistor, the temperature of the thermistor is not equal to the current operating temperature of the laser. The temperature measured by this method is not the real-time operating temperature of the laser. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for real-time detection of laser temperature, which can realize real-time detection of the temperature of a semiconductor laser.

[0005] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0006] A method for real-time detection of laser temperature comprises the following steps:

[0007] Acquire a first light intensity of the laser light emitted by the laser to be tested after the laser light passes through the gasless gas cell;

[0008] Acquire a second light intensity of the laser light emitted by the laser to be tested after the laser light passes through a gas cell filled with an absorbing gas of known concentration;

[0009] Determining the line intensity of the laser light emitted by the laser to be tested according to the acquired first light intensity and second light intensity;

[0010] Determine the wavelength of the laser emitted by the laser to be tested according to the line intensity of the laser emitted by the laser to be tested;

[0011] The current operating temperature of the laser to be tested is determined according to the wavelength of the laser emitted by the laser to be tested.

[0012] Preferably, determining the line intensity of the laser emitted by the laser to be tested according to the acquired first light intensity and second light intensity includes:

[0013] Calculating a gas absorption cross section of the absorbing gas according to the acquired first light intensity and second light intensity;

[0014] The line intensity of the laser emitted by the laser to be tested is determined based on the gas absorption cross section of the absorbing gas.

[0015] Preferably, calculating the gas absorption cross section of the absorbing gas according to the acquired first light intensity and second light intensity includes:

[0016] According to the exponential relationship between the ratio of the first light intensity to the second light intensity and the gas absorption cross section of the absorbing gas, the gas absorption cross section of the absorbing gas is calculated based on the acquired first light intensity and second light intensity.

[0017] Preferably, the gas absorption cross section of the absorbing gas is calculated as follows:

[0018]

[0019] in, is the gas absorption cross section of the absorbing gas, is the first light intensity, is the second light intensity, is the gas pool length, is the concentration of the absorbed gas.

[0020] Preferably, determining the line intensity of the laser emitted by the laser to be tested according to the gas absorption cross section of the absorbing gas includes:

[0021] The wave number is integrated using the gas absorption cross section of the absorbing gas to obtain the line intensity of the laser emitted by the laser to be measured.

[0022] Preferably, determining the wavelength of the laser emitted by the laser to be tested according to the line intensity of the laser emitted by the laser to be tested comprises:

[0023] Obtaining the absorption line profile of the absorbing gas molecule with respect to the pre-established line intensity with respect to the wavelength;

[0024] The wavelength of the corresponding laser emitted by the laser to be tested is determined according to the position of the line intensity of the laser emitted by the laser to be tested in the absorption spectrum of the absorbing gas molecules.

[0025] Preferably, determining the current operating temperature of the laser to be tested according to the wavelength of the laser emitted by the laser to be tested includes:

[0026] According to the linear relationship between the working wavelength and the working temperature of the laser, the current working temperature of the laser to be measured is calculated based on the wavelength of the laser emitted by the laser to be measured.

[0027] Preferably, the current operating temperature of the laser to be tested is calculated as follows:

[0028]

[0029] in, is the current operating temperature of the laser to be tested, is the wavelength of the laser emitted by the laser to be tested, is the operating wavelength of the laser to be tested at the reference operating temperature, is the wavelength temperature modulation coefficient of the laser to be measured, is the reference operating temperature of the laser to be tested.

[0030] Preferably, the central spectral line wavelength of the molecular absorption spectrum of the absorbing gas corresponds to the operating wavelength of the laser to be measured at the reference operating temperature.

[0031] Preferably, the laser temperature real-time detection system for acquiring the first light intensity and the second light intensity comprises:

[0032] The laser to be tested, the gas cell, the photodetector and the photocurrent amplification and detection circuit are arranged in sequence.

[0033] The present invention has the following beneficial effects:

[0034] This embodiment utilizes the real-time correlation between the emission wavelength of the laser to be tested and its operating temperature. By selecting the molecular absorption spectrum of a specific absorbing gas and the absorption effect of the laser to be tested, the real-time operating wavelength of the laser is accurately tested in combination with the characteristics of the correlation between the molecular absorption spectrum line type and the laser wavelength. The real-time operating wavelength is then used to calculate the real-time operating temperature, thereby improving the real-time and accuracy of laser temperature detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a flow chart of a method for real-time detection of laser temperature;

[0036] Figure 2 This is a schematic diagram of the structure of the laser temperature real-time detection system without inflation;

[0037] Figure 3 A schematic diagram of the structure for inflating the laser temperature real-time detection system;

[0038] Figure 4 This is a schematic diagram of the absorption spectrum of absorbing gas molecules;

[0039] Figure 5It is a schematic diagram of the structure of the 1653nm semiconductor laser temperature real-time detection system without gas filling;

[0040] Figure 6 Schematic diagram of the structure of the inflation system for the real-time temperature detection system of the 1653nm semiconductor laser. DETAILED DESCRIPTION

[0041] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0042] like Figure 1 As shown, a method for real-time detection of laser temperature provided by an embodiment of the present invention includes the following steps S1 to S5:

[0043] S1, obtaining a first light intensity of the laser emitted by the laser to be tested after passing through the gasless gas pool;

[0044] S2, obtaining a second light intensity of the laser light emitted by the laser to be tested after the laser light passes through a gas pool filled with an absorbing gas of known concentration;

[0045] S3, determining the line intensity of the laser emitted by the laser to be tested according to the acquired first light intensity and second light intensity;

[0046] S4, determining the wavelength of the laser emitted by the laser to be tested according to the line intensity of the laser emitted by the laser to be tested;

[0047] S5. Determine the current operating temperature of the laser to be tested according to the wavelength of the laser emitted by the laser to be tested.

[0048] This embodiment utilizes the real-time correlation between the emission wavelength of the laser to be tested and its operating temperature. By selecting the molecular absorption spectrum of a specific absorbing gas and the absorption effect of the laser to be tested, the real-time operating wavelength of the laser is accurately tested in combination with the characteristics of the correlation between the molecular absorption spectrum line type and the laser wavelength. The real-time operating wavelength is then used to calculate the real-time operating temperature, thereby improving the real-time and accuracy of laser temperature detection.

[0049] The main advantage of this embodiment is that the measured laser temperature is real-time, and there is no time lag problem caused by any heat conduction. Since the line width of the gas molecule absorption spectrum is very narrow, usually less than 0.1nm, the above method of deriving the wavelength through the gas absorption cross section has an extremely high wavelength resolution (better than 0.01nm). Then the real-time temperature is calculated by wavelength. Since the wavelength temperature modulation coefficient of the semiconductor laser is usually around 0.2 nm / ℃, this embodiment has an extremely high temperature resolution, better than 0.05℃ (0.01nm÷0.2nm / ℃). And this embodiment can not only detect the temperature of the semiconductor laser in real time, but also can be extended to the real-time temperature detection of other lasers with temperature wavelength modulation effect.

[0050] In an optional embodiment of the present invention, Figure 2 As shown, the laser temperature real-time detection system constructed in this embodiment includes: a laser to be tested 101, a gas pool 103, a photodetector 105 and a photocurrent amplification and detection circuit 106 which are arranged in sequence.

[0051] The laser 101 to be tested, the photodetector 105, and the photocurrent amplification and detection circuit 106 in this embodiment can all utilize the existing components of the optical module in the optical communication system. It is only necessary to add a gas pool 103 (such as using a collimating lens to encapsulate a small section of reference gas) to the optical module to achieve it. Using the above method, the system components involved in this embodiment can be fully integrated into the optical module of the optical communication system, so that the optical module has real-time laser self-temperature detection capabilities. If the temperature is calculated by the traditional laser wavelength measurement method, that is, a spectrometer is used for measurement. Since the spectrometer measures the wavelength based on the dispersion principle, it is usually a large-scale device or apparatus and cannot be integrated into the optical module, and cannot be used for real-time detection of the laser temperature of the optical module in the optical communication system.

[0052] In an optional embodiment of the present invention, in step S1 of this embodiment, when the laser 101 to be tested is working, the first light intensity of the laser 104 after the laser 102 emitted by the laser 101 to be tested passes through the gasless gas pool is measured by the photodetector 105 and the photocurrent amplification and detection circuit 106. .

[0053] In an optional embodiment of the present invention, in step S2 of this embodiment, the gas pool 103 is filled with an absorption gas of known concentration, such as Figure 3 It should be noted that the absorbing gas to be filled should be a gas whose central spectral line wavelength of the molecular absorption spectrum is consistent with the typical working wavelength of the laser to be tested. The second light intensity of the laser 104 emitted by the laser to be tested after being absorbed by the gas in the gas pool is measured by the photodetector 105 and the photocurrent amplification and detection circuit 106. .

[0054] In an optional embodiment of the present invention, step S3 of this embodiment determines the line intensity of the laser emitted by the laser to be tested according to the acquired first light intensity and second light intensity, including:

[0055] Calculating a gas absorption cross section of the absorbing gas according to the acquired first light intensity and second light intensity;

[0056] The line intensity of the laser emitted by the laser to be tested is determined based on the gas absorption cross section of the absorbing gas.

[0057] The gas absorption cross section of the absorbing gas is calculated according to the acquired first light intensity and second light intensity, including:

[0058] According to the exponential relationship between the ratio of the first light intensity to the second light intensity and the gas absorption cross section of the absorbing gas, the gas absorption cross section of the absorbing gas is calculated based on the acquired first light intensity and second light intensity, and the calculation method is:

[0059]

[0060] in, is the gas absorption cross section of the absorbing gas, is the first light intensity, is the second light intensity, is the gas pool length, is the concentration of the absorbed gas.

[0061] The line intensity of the laser emitted by the laser to be tested is determined according to the gas absorption cross section of the absorbing gas, including:

[0062] The wave number is integrated using the gas absorption cross section of the absorbing gas to obtain the line intensity of the laser emitted by the laser to be measured.

[0063] In this embodiment, the wave number is represented by the inverse of the wavelength.

[0064] In an optional embodiment of the present invention, step S4 of this embodiment determines the wavelength of the laser emitted by the laser to be tested according to the line intensity of the laser emitted by the laser to be tested, including:

[0065] Obtaining the absorption line profile of the absorbing gas molecule with respect to the pre-established line intensity with respect to the wavelength;

[0066] The wavelength of the corresponding laser emitted by the laser to be tested is determined according to the position of the line intensity of the laser emitted by the laser to be tested in the absorption spectrum of the absorbing gas molecules.

[0067] This embodiment first establishes the absorption spectrum line shape of the absorbing gas near the typical working wavelength of the laser to be tested based on the nonlinear relationship between the line intensity and the wavelength, such as Figure 4As shown in the figure, since the line shape is a curve of line intensity with respect to wavelength, the accurate wavelength λ of the laser to be tested can be obtained.

[0068] In an optional embodiment of the present invention, step S5 of this embodiment determines the current operating temperature of the laser to be tested according to the wavelength of the laser emitted by the laser to be tested, including:

[0069] According to the linear relationship between the laser operating wavelength and the operating temperature, the current operating temperature of the laser to be tested is calculated based on the wavelength of the laser emitted by the laser to be tested. The calculation method is:

[0070]

[0071] in, is the current operating temperature of the laser to be tested, is the wavelength of the laser emitted by the laser to be tested, is the operating wavelength of the laser to be tested at the reference operating temperature, is the wavelength temperature modulation coefficient of the laser to be measured, is the reference operating temperature of the laser to be tested.

[0072] The present invention takes the real-time measurement of the working temperature of a semiconductor laser with a typical working wavelength of 1653 nm as an example. Figure 5 The components shown are used to build a detection system opposite to the laser 101 to be tested, including a l The gas pool 103 (in this embodiment, the l =5cm), the photodetector 105 and the photocurrent amplification and detection circuit 106, it is necessary to ensure that the laser light emitted by the laser 101 to be tested can pass through the gas pool 103 to reach the photodetector 105.

[0073] According to step S1, when the laser 101 to be tested is working, the first light intensity of the laser 104 after the laser 102 emitted by the laser 101 to be tested passes through the gasless gas pool is measured by the photodetector 105 and the photocurrent amplification and detection circuit 106. I o .

[0074] According to step S2, methane gas with a concentration of c (mol / L) is filled into the gas pool 103. Figure 5 The second light intensity of the laser 104 after the laser 102 emitted by the laser to be tested is measured by the photodetector 105 and the photocurrent amplification and detection circuit 106 after being absorbed by the gas in the gas pool. I t .

[0075] According to step S3, based on the measured first light intensity I oand the second light intensity I t , calculate the current gas absorption cross section of methane k . Using gas absorption cross section Line strength can be obtained by integrating the wavenumber s .

[0076] According to step S4, the molecular absorption line type of methane near 1653 nm is established, such as Figure 6 As shown. Since the line type is a curve of line intensity with respect to wavelength, the accurate wavelength of the laser 101 to be tested can be obtained. λ .

[0077] According to step S5, according to the relationship between the working wavelength λ of the laser to be measured and the working temperature T λ=λ 0 +β•(T-25℃),λ 0 is the wavelength of the laser at 25°C (nm), with λ 0 =1653.20nm as an example; β is the wavelength temperature modulation coefficient of the laser (nm / ℃), and the typical wavelength temperature modulation coefficient of the laser corresponding to this embodiment is β=0.18 nm / ℃ as an example, and the current operating temperature of the laser 101 to be tested can be calculated:

[0078] T = (λ - λ 0 ) / β+ 25℃ =(1653.71nm-1653.20nm) / (0.18 nm / ℃)+ 25℃=27.83℃.

[0079] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0080] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1A function specified in one or more boxes.

[0081] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0082] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0083] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A method for real-time detection of laser temperature, characterized in that: The following steps are involved: Acquire a first light intensity of the laser light emitted by the laser to be tested after the laser light passes through the gasless gas cell; Acquire a second light intensity of the laser light emitted by the laser to be tested after the laser light passes through a gas cell filled with an absorbing gas of known concentration; Determining the line intensity of the laser light emitted by the laser to be tested according to the acquired first light intensity and second light intensity; According to the line intensity of the laser emitted by the laser to be tested, the wavelength of the laser emitted by the laser to be tested is determined, including: Obtaining the absorption line profile of the absorbing gas molecule with respect to the pre-established line intensity with respect to the wavelength; Determine the wavelength of the laser emitted by the laser to be tested according to the position of the line intensity of the laser emitted by the laser to be tested in the absorption spectrum line type of the absorbing gas molecules; According to the wavelength of the laser emitted by the laser to be tested, the current operating temperature of the laser to be tested is determined, including: According to the linear relationship between the laser operating wavelength and the operating temperature, the current operating temperature of the laser to be tested is calculated based on the wavelength of the laser emitted by the laser to be tested. The calculation method is: in, is the current operating temperature of the laser to be tested, is the wavelength of the laser emitted by the laser to be tested, is the operating wavelength of the laser to be tested at the reference operating temperature, is the wavelength temperature modulation coefficient of the laser to be measured, is the reference operating temperature of the laser to be tested.

2. A method for real-time detection of laser temperature according to claim 1, characterized in that: Determining the line intensity of the laser emitted by the laser to be tested according to the acquired first light intensity and second light intensity includes: Calculating a gas absorption cross section of the absorbing gas according to the acquired first light intensity and second light intensity; The line intensity of the laser emitted by the laser to be tested is determined based on the gas absorption cross section of the absorbing gas.

3. A method for real-time detection of laser temperature according to claim 2, characterized in that: Calculating a gas absorption cross section of the absorbing gas according to the acquired first light intensity and second light intensity, including: According to the exponential relationship between the ratio of the first light intensity to the second light intensity and the gas absorption cross section of the absorbing gas, the gas absorption cross section of the absorbing gas is calculated based on the acquired first light intensity and second light intensity.

4. A method for real-time detection of laser temperature according to claim 3, characterized in that: The gas absorption cross section for an absorbing gas is calculated as: in, is the gas absorption cross section of the absorbing gas, is the first light intensity, is the second light intensity, is the gas pool length, is the concentration of the absorbed gas.

5. A method for real-time detection of laser temperature according to claim 2, characterized in that: According to the gas absorption cross section of the absorbing gas, the line intensity of the laser emitted by the laser to be tested is determined, including: The wave number is integrated using the gas absorption cross section of the absorbing gas to obtain the line intensity of the laser emitted by the laser to be measured.

6. A method for real-time detection of laser temperature according to claim 1, characterized in that: The central spectral line wavelength of the molecular absorption spectrum of the absorbing gas corresponds to the operating wavelength of the laser to be measured at the reference operating temperature.

7. A method for real-time detection of laser temperature according to claim 1, characterized in that: A laser temperature real-time detection system for obtaining a first light intensity and a second light intensity comprises: The laser to be tested, the gas cell, the photodetector and the photocurrent amplification and detection circuit are arranged in sequence.

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