WO2023228247A1

WO2023228247A1 - Manufacturing method and manufacturing device for wavelength conversion module

Info

Publication number: WO2023228247A1
Application number: PCT/JP2022/021119
Authority: WO
Inventors: 晃次圓佛
Original assignee: 日本電信電話株式会社
Priority date: 2022-05-23
Filing date: 2022-05-23
Publication date: 2023-11-30

Abstract

This manufacturing method for a wavelength conversion module of the present disclosure provides an efficient procedure for operating a wavelength conversion element at a desired operating wavelength while simultaneously attaching an optical fiber to the module. By automating most of the processes under computer control, the problem of element temperature fluctuations that are unique to wavelength conversion elements during the manufacturing process can be addressed, and the mass productivity of pigtail modules can be improved. The manufacturing method for a wavelength conversion module of the present disclosure also has the aspect of a manufacturing device including a computer for the wavelength conversion module.

Description

Manufacturing method and manufacturing device for wavelength conversion module

The present invention relates to a method and apparatus for manufacturing a wavelength conversion module.

Wavelength conversion technology is used in various application fields such as optical signal wavelength conversion in optical communications, optical processing, medical care, and bioengineering. In optical communication systems, wavelength conversion technology is also used, for example, in wavelength conversion devices that perform wavelength conversion operations based on difference frequency generation and amplification operations using parametric effects, which will be described later. Focusing on materials used for wavelength conversion, periodically poled lithium niobate (PPLN) waveguide elements made of lithium niobate (LiNbO ₃ ), which is a second-order nonlinear material and has a large nonlinear constant, are used for wavelength conversion. It is widely used as a light source due to its high efficiency.

The second-order nonlinear optical effect utilizes a wavelength conversion mechanism in which light with a wavelength λ ₁ and light with a wavelength λ ₂ are input into a second-order nonlinear medium to generate a new wavelength λ ₃ . The wavelength conversion expressed by the following equation is called sum frequency generation (SFG).
1/λ ₃ = 1/λ ₁ + 1/λ ₂ Equation (1)
Further, wavelength conversion that satisfies the following equation, which is a modification of equation (1) with λ ₁ =λ ₂ , is called second harmonic generation (SHG).
λ ₃ = λ ₁ /2 Equation (2)
Furthermore, wavelength conversion that satisfies the following equation is called difference frequency generation (DFG).
1/λ ₃ =1/λ ₁ -1/λ ₂ Equation (3)
The wavelength λ ₁ used to generate the difference frequency according to the above equation (3) is called pump light, λ ₂ is called signal light, and λ ₃ is called idler light. Furthermore, it is also possible to construct an optical parametric oscillator that generates λ ₂ and λ ₃ that satisfy equation (3) by inserting a nonlinear medium into a resonator and inputting only λ ₁ .

In recent years, improvements in wavelength conversion efficiency have made it possible to perform optical amplification operations using second-order nonlinear effects in the field of communications. This optical amplifier is called a Phase Sensitive Amplifier (PSA), and it can amplify input light without degrading the signal-to-noise ratio, and is expected to be used as an optical amplifier for long-distance transmission in place of erbium-doped fiber amplifiers. has been done.

Two amplification operations are known in PSA. One method utilizes degenerate parametric amplification in which a signal light and a pumping light having a wavelength half the wavelength of the signal light are input into a secondary nonlinear medium to amplify the signal light (Non-Patent Document 1). The other method uses non-degenerate parametric amplification to amplify the signal light and idler light by inputting a pair of signal light and idler light, and a pump light having a wavelength that is the sum of the frequencies of the signal light and idler light ( Non-patent document 2). The signal light and idler light pair are generated by the DFG mechanism described above.

When wavelength conversion technology is used in the communication field, DFG and optical parametric amplification (OPA) are mainly used among the mechanisms based on the above-mentioned second-order nonlinear effect. In each of the DFG and OPA mechanisms, the signal light and idler light are in the 1.55 μm communication wavelength band, so the excitation light is in the 0.78 μm band.

FIG. 1 is a diagram showing the basic configuration of a wavelength conversion module. FIG. 1(b) is a top view (xy plane) of the wavelength conversion module 100, and FIG. 1(a) is a cross-sectional view (yz (surface) is shown in a partially simplified manner. The wavelength conversion module 100 receives fundamental wave light from the optical window 105-1 and generates second harmonic light (SHG light), which is a type of sum frequency light, from the optical window 108-2. The wavelength conversion module 100 includes, in a metal housing 101, a wavelength conversion element 102, a temperature control element 103, and a metal plate 104 that serves as a support for the wavelength conversion element. The metal housing 101 includes fundamental wave optical windows 105-1 and 105-2 and SHG light optical windows 108-1 and 108-2. It includes lenses 106 before and after the wavelength conversion element 102, and further includes optical filters 107-1 and 107-2 and other filter elements for separating fundamental wave light and SHG light. The wavelength conversion element 102 is, for example, a PPLN element.

Although FIG. 1 shows a configuration including a wavelength conversion element for SHG light generation, two lights with different wavelengths are converted from the fundamental wave optical window 105-1 and the SHG light optical window 108-2 on one side of the module. By inputting the information to the elements, modules for mechanisms such as PSA and OPA can also be realized. Further, in the wavelength conversion module 100 of FIG. 1, arrows indicate the propagation direction of light when the fundamental wave light is inputted from the optical window 105-1 and the SHG light is outputted from the optical window 108-2. However, even if the light propagation direction is opposite to that shown in FIG. 1, SHG light can be generated from the fundamental light in the same way. Fundamental wave light can also be input from the optical window 105-2 and SHG light can be output from the optical window 108-2, and the wavelength conversion module 100 has a symmetrical structure between input and output.

As shown in FIG. 1, the wavelength conversion module 100 has a structure that can input and output a plurality of lights with different wavelengths. Devices equipped with such modules have often been constructed with spatial optical system components using bulk optical components due to easy availability. In recent years, the development of optical fiber communication devices has progressed, and optical fiber-type optical components and optical waveguide-type optical components for communication wavelength bands have become widely available. Devices equipped with wavelength conversion modules are also beginning to adopt the form of pigtail modules, which emphasize easy optical coupling with optical fibers. The pigtail type module is small, does not require optical alignment, and is versatile enough to implement any of the wavelength conversion, PSA, and OPA configurations. For wider use, there is a need for manufacturing methods and equipment that can produce pigtail modules at low cost.

The PPLN element 102 of the wavelength conversion module 100 in FIG. 1 uses quasi-phase matching (QPM). In a PPLN element with a single-period QPM structure, the phase matching wavelength is determined when the period of the repeating structure is determined. Since the refractive index of a nonlinear optical material has temperature dependence, it is necessary to set and control the optimum temperature of the PPLN element in order to achieve highly efficient wavelength conversion.

However, when making a PPLN element into a module, there was a problem in that the phase matching wavelength fluctuated during various steps from obtaining the characteristics of the element alone to fixing all the fibers to the module. The process of attaching the fiber to the module involves a complicated and complicated process performed by skilled workers, and is not suitable for mass production. The present invention provides a method and apparatus for manufacturing a pigtail module with excellent mass productivity.

One aspect of the present invention is a method for manufacturing an optical module including a wavelength conversion element and a temperature control element fixed to the wavelength conversion element via a metal plate, wherein the wavelength conversion element is heated to an initial temperature. adjusting the input fiber so that the transmitted light of the fundamental wave light is maximized; and modifying the current temperature of the wavelength conversion element, the step of adjusting the current temperature of the wavelength conversion element, Sweeping the wavelength to determine a peak wavelength at which the level of the wavelength-converted light is maximum, based on the operating wavelength of the wavelength conversion element, the peak wavelength, the current temperature and the temperature dependence coefficient of the phase matching wavelength, a step of correcting, the step comprising calculating a corrected temperature of the wavelength conversion element; and resetting the wavelength conversion element to the corrected temperature; and at the corrected temperature, the wavelength converted light This manufacturing method includes the steps of: realigning the input fiber so that the level of the input fiber is maximized; and fixing the aligned input fiber to a metal casing of the optical module.

Another aspect of the present invention is a method for manufacturing an optical module including a wavelength conversion element and a temperature control element fixed to the wavelength conversion element via a metal plate, and connected to a fundamental wave input fiber. , a step of setting the wavelength conversion element to an initial temperature, a step of aligning the output fiber so that transmitted light of the fundamental wave light is maximized, and a step of correcting the current temperature of the wavelength conversion element. , a step of sweeping the wavelength of the fundamental light in a predetermined wavelength range to determine a peak wavelength at which the level of the wavelength-converted light is maximum; the operating wavelength of the wavelength conversion element, the peak wavelength, the current temperature and phase; calculating a modified temperature of the wavelength conversion element based on the temperature dependence coefficient of the matched wavelength; and resetting the wavelength conversion element to the modified temperature; realigning the output fiber so that the level of the wavelength-converted light is maximized at the corrected temperature; and fixing the aligned output fiber to a metal casing of the optical module. This is a manufacturing method comprising:

A method and apparatus for manufacturing a pigtail wavelength conversion module that is highly mass-producible is provided.

FIG. 2 is a diagram showing the basic configuration of a wavelength conversion module using PPLN elements. It is a figure showing the outline of a manufacturing process of a wavelength conversion module containing a PPLN element. It is a figure which shows the change of the phase matching curve before and after fixing of a wavelength conversion element. FIG. 4 is a diagram illustrating the temperature dependence of the phase matching wavelength before and after fixing the element. FIG. 3 is a diagram illustrating changes in operating wavelength through the manufacturing process of a wavelength conversion module. It is a figure explaining the procedure of connecting four PTFs to a wavelength conversion module. 1 is a diagram illustrating an apparatus that implements a method for manufacturing a wavelength conversion module according to the present disclosure. FIG. 2 is a flow diagram illustrating the steps of a method for manufacturing a wavelength conversion module according to the present disclosure. It is a figure explaining the principle of calculating|requiring the corrected temperature of a wavelength conversion element. It is a figure which shows another structure of the apparatus which implements the wavelength conversion module manufacturing method. It is a figure which shows the other structure of the apparatus which implements the wavelength conversion module manufacturing method. It is a flowchart explaining another procedure of the manufacturing method of a wavelength conversion module. FIG. 2 is a diagram illustrating the configuration of initial data in the manufacturing method of the present disclosure.

The method of manufacturing a wavelength conversion module of the present disclosure provides an efficient procedure for operating a PPLN element at a desired operating wavelength while simultaneously attaching an optical fiber to the module. By automating most of the processes under computer control, the problem of element temperature fluctuations peculiar to PPLN elements during the manufacturing process is addressed, and the mass productivity of pigtail type modules is improved. The wavelength conversion module manufacturing method of the present disclosure also has the aspect of a wavelength conversion module manufacturing apparatus including a computer. Hereinafter, specific problems in a wavelength conversion module including a PPLN element will be described, and then a method for manufacturing a wavelength conversion module of the present disclosure, and a configuration, operation, and procedure of a manufacturing apparatus will be described in detail.

FIG. 2 is a diagram showing an outline of the manufacturing process of a wavelength conversion module including a PPLN element. The manufacturing process begins with a chip sorting process 11 for PPLN elements. In this step 11, chips that include a PPLN waveguide used for modularization and have wavelength conversion performance according to the intended function are selected. This chip sorting step 11 includes a chip data acquisition step 15 in parallel. In this step 15, chip data is acquired for each chip or each product type, including at least a predetermined operating wavelength λ _init corresponding to the phase matching wavelength and an initial temperature T _init corresponding to the operating wavelength in step 15. be done. The operating wavelength is a different value for each product type depending on the intended function, and can be the same wavelength for products of the same type. Different values of the operating wavelength λ _init may be set within the wavelength range for products of the same type.

Once the operating wavelength λ _init is determined for a certain PPLN element, the principle is to consistently operate it at the same operating wavelength λ _init even after modularization. The initial temperature T _init means the temperature at which the element should be set in order to achieve a phase matching state at the operating wavelength λ _init . Therefore, in this chip data acquisition step 15, there is a one-to-one correspondence between the operating wavelength λ _init and the initial temperature T _init .

Following step 11 in FIG. 2, step 12 of incorporating the chip into the module housing and fixing the chip is performed. In order to stably hold the wavelength conversion element 102 and uniformly control the temperature of the entire element during modularization, the wavelength conversion element 102 is fixed to a metal plate 104 serving as a support, as shown in FIG. . When a wavelength conversion element 102 such as a PPLN element is fixed to a metal plate 104, a stress change occurs inside the wavelength conversion element 102 due to the difference in thermal expansion coefficient between the element and the metal plate. Due to such stress changes, the refractive index of the wavelength conversion element 102 changes due to photoelastic effects, piezoelectric effects, Pockels effects, and the like. Therefore, the actual operating wavelength of the wavelength conversion element 102 once mounted on the module in the chip fixing step 12 deviates from the initial temperature T _init obtained in the step 15 . That is, even if the initial temperature T _init obtained in the chip data acquisition step 15 is set after the wavelength conversion element is mounted on the module in step 12, a phase matching state cannot be obtained. The details of this problem are further explained in FIGS. 3 and 4.

Following the chip fixing step 12, a step 13 of setting a pigtail fiber (hereinafter abbreviated as PTF for simplicity) in the module, aligning it, searching and optimizing the chip temperature, and a step of fixing the PTF to the module. 14 follows. The method for manufacturing a wavelength conversion module of the present disclosure, which will be described later, corresponds to

steps

13 and 14. In the wavelength conversion module manufacturing method of the present disclosure, the chip data including the initial temperature acquired in the chip sorting step 11 is updated to the corrected temperature and others in the PTF fixing step 16.

FIG. 3 is a diagram showing changes in the phase matching curve before and after fixing the wavelength conversion element. In FIG. 3, the vertical axis shows the transmitted light output spectrum 10 and the SHG

optical output spectra

20 and 21 of the fundamental wave light in arbitrary units (au) with respect to the wavelength (nm) of the input fundamental wave light on the horizontal axis. The transmitted light output spectrum 10 of the fundamental wave light is obtained as the output from the optical window 105-2 on the opposite side of the module by inputting the fundamental wave light through the optical window 105-1 in FIG. The SHG optical output spectrum is obtained as the output from the optical window 108-1. The SHG

optical output spectra

20 and 21 are phase matching curves obtained when measuring the chip alone at the initial temperature T _init and when setting the chip to the same initial temperature T _init after fixing it to a metal plate, respectively. It shows. That is, it corresponds to the phase matching curve 20 obtained in steps 11 and 15 in FIG. 2, and the phase matching curve 21 after completing the chip fixing step 12 in FIG. The peak wavelength of the phase matching curve 20 is the operating wavelength λ _init .

As is clear from FIG. 3, even if the initial temperature T _init is set, the phase matching curve changes significantly before and after fixing the wavelength conversion element. Conversely, after the chip is fixed to a metal plate, in order to achieve a phase matching state with a peak at the operating wavelength λ _init , the chip temperature must be corrected from the initial temperature T _init .

FIG. 4 is a diagram illustrating the temperature dependence of the phase matching wavelength before and after fixing the wavelength conversion element. The horizontal axis shows the set temperature of the chip (° C.), and the horizontal axis shows the peak wavelength of the SHG light, that is, the phase matching wavelength (nm). The phase matching wavelength has an approximately linear temperature dependence, and from the temperature dependence curve 22 obtained in the sorting step 11 before and after fixing the chip of the wavelength conversion element, it can be seen that The temperature dependence curve 23 changes. The slope of the temperature dependence curve corresponds to the temperature dependence coefficient (nm/°C), and the temperature dependence coefficient also changes before and after the chip is fixed. In addition, in FIG. 4, for the purpose of explanation, the change in temperature dependence before and after fixing the chip is illustrated with a little emphasis.

As described above, the phase matching wavelength obtained by setting the chip to the initial temperature T _init changes before and after fixing the wavelength conversion element to the module. As shown in Figure 3, the phase matching curve, which has a bandwidth of only about 0.5 nm, deviates, so even if fundamental wave light with the operating wavelength λ _init is input, SHG light of the desired wavelength cannot be obtained at all. . Not only is it impossible to achieve the desired wavelength conversion function, but also alignment of the PTF cannot be performed unless SHG light is obtained. Therefore, after fixing the wavelength conversion element to the module, it is necessary to find the "corrected temperature" at which the phase matching is achieved at the operating wavelength λ _init in the most efficient way possible. In order to determine the "corrected temperature" of the wavelength conversion element, the element temperature must be changed. In order to efficiently search for a "modified temperature," it is also necessary to avoid prolonging the time it takes for the device characteristics to stabilize. In addition, stress changes occurring inside the wavelength conversion element may also occur due to impact during the process of welding and fixing the fiber. It is also necessary to consider the possibility that a variation similar to the above-mentioned variation in the phase matching wavelength when fixing the chip occurs each time the fiber is fixed to the module housing.

The method for manufacturing a wavelength conversion module of the present disclosure solves or at least alleviates the above-mentioned problems, and significantly improves mass productivity by automating the module mounting process that previously relied on skilled workers.

FIG. 5 is a diagram illustrating variations in the phase matching wavelength through the manufacturing process of the wavelength conversion module. In the chip selection step 31, a specific type of wavelength conversion element is selected based on the intended operating wavelength λ _init . In an actual sorting process, a certain adjustment variation width exists at the operating wavelength λ _init . In the chip sorting step 31, an initial temperature T _init corresponding to the operating wavelength λ _init is determined. In step 32 after fixing the wavelength conversion element chip to the metal plate, the actual operating wavelength at which the chip is phase matched when set at the initial temperature T _init varies as explained in FIG. 4 . Since the amount of fluctuation caused by fixing the chip also varies, the actual operating wavelength variation when the initial temperature T _init is set increases.

In the method for manufacturing a wavelength conversion module of the present disclosure, in step 33 of module assembly including attaching the PTF to the module, a "corrected temperature" that achieves a phase matching state at the operating wavelength λ _init is determined and readjusted. In this way, variations in the actual operating wavelength can be kept within a certain range.

In the following description, as shown in FIG. 1, the wavelength conversion element 102 has two optical windows on one side (input side) and two optical windows on the other side (output side). - A wavelength conversion module with a total of 4 ports of 2 outputs will be explained as an example. A case will be described in which a fundamental wave in the 1535 nm band is input to the input port, and transmitted light of the input light and SHG light in the 775 nm wavelength band are output from the output port. Four PTFs are sequentially connected to the four ports to complete a pigtail module. Note that depending on the function to be realized, light of two different wavelengths may be input from the input side port.

FIG. 6 is a diagram illustrating an overview of the procedure for connecting four PTFs to the wavelength conversion module. The wavelength conversion module 100 is a simplified version of the wavelength conversion module shown in FIG. Port 1 corresponds to the fundamental wave optical port of optical window 105-1, and port 3 corresponds to the fundamental wave optical port of optical window 105-2. Port 2 corresponds to the SHG light output port of optical window 108-1, and port 4 corresponds to the SHG light output port of optical window 106-2. In the manufacturing method described below, the fundamental wave port is used as an input port for fundamental wave light and an output port for transmitted light of fundamental wave light.

FIG. 6A shows the step of connecting the first input PTF 202-1 to port 1, in which a fundamental wave 212 detector 203 and a SHG light 213 detector 206 are used. In the step of connecting the first input PTF, initial data including the initial temperature T _init acquired at the time of chip sorting is used. FIG. 7 shows a specific configuration of the manufacturing apparatus, and the flow of the manufacturing method will be explained with FIG. 8.

FIG. 6(b) shows the stage of connecting the second input PTF 202-2 to port 3, and the input PTF 202-1 is already connected to port 1. A fundamental wave light detector 210 and a SHG light 213 detector 206 connected to the input PTF 202-1 are used. FIG. 10 shows a specific configuration of the manufacturing apparatus, and the flow of the manufacturing method is generally the same as that in FIG. 8. It should be noted that in the process of connecting the second and subsequent PTFs, updated data including the corrected temperature obtained in the process of connecting the first input PTF is used.

(c) of FIG. 6 shows the stage of connecting the third output PTF 211-1 to port 4, and two input PTFs 202-1 and 202-2 are already connected to

ports

1 and 3. . A wavelength swept light source (SW) 201 is connected to the input PTF 202-1, and a fundamental wave light detector 210 is connected to the input PTF 202-2. FIG. 11 shows a specific configuration of the manufacturing apparatus, and the flow of the manufacturing method will be explained with FIG. 12. Updated data including corrected temperatures is utilized.

FIG. 6(d) shows the stage of connecting the fourth output PTF 211-2 to port 2, and three PTFs are already connected to the wavelength conversion module 100. A wavelength swept light source 201 is connected to the input PTF 202-2, and a fundamental wave light detector 210 is connected to the input PTF 202-1. The flow of the manufacturing method is generally the same as that shown in FIG. Updated data including corrected temperatures is utilized.

Hereinafter, the manufacturing method for connecting a PTF for fundamental wave light input and the manufacturing method for connecting a PTF for SHG light output will be explained in detail, and the steps thereof will be explained in detail.

FIG. 7 is a diagram showing the configuration of an apparatus that implements the method for manufacturing a wavelength conversion module of the present disclosure. The manufacturing apparatus connects the PTF to the wavelength conversion module 100 and has a configuration for searching and determining a modified operating temperature for operating the wavelength conversion element at a desired operating wavelength. The manufacturing equipment includes a wavelength-sweepable light source 201 that supplies fundamental wave light, a detector 206 that detects SHG light 213 and converts it into an electric signal, and a detector 207 that detects transmitted light 212 of the fundamental wave light and converts it into an electric signal. including. Further, a centering device 203 is used to adjust the position of the PTF at the fiber connection point to align the optical axis between the waveguide in the chip and the core of the PTF, and the position of the lens 205-1 is adjusted. It also includes a lens aligner 204. The elements described above are controlled by computer 208. Although not shown, computer 208 includes a processor, memory, and an A/D converter that converts electrical signals from

detectors

206, 207 into digital data. Computer 208 may be connected to an external storage device or network (not shown).

In the method for manufacturing a wavelength conversion module of the present disclosure, the initial data of the wavelength conversion element obtained in advance in the chip sorting step is read from a memory or the like and used in the flow of the manufacturing method described below. The initial data is updated during the flow of the manufacturing method. The initial data may be stored in memory within computer 208, on an external storage medium, or on a network.

FIG. 13 is a diagram illustrating the configuration of initial data of the wavelength conversion element in the manufacturing method of the present disclosure. FIG. 13(a) shows initial data acquired in the chip sorting process. (b) shows data updated in the flow of the manufacturing method described later. For example, data on a wavelength conversion element may include an element identification number, an operating wavelength, an initial temperature, a temperature dependence coefficient of a phase matching wavelength, a wavelength conversion efficiency, a loss element characteristic, and the like. A file in a format such as a table is saved in the memory of a computer, and this file is read from the control program of the manufacturing method. The PTF mounted in the module is identified by the element identification number, etc., and the wavelength of the light source 201 and the set temperature of the temperature control element (temperature regulator) inside the module are controlled.

FIG. 8 is a flow diagram illustrating the steps of the method for manufacturing a wavelength conversion module of the present disclosure. The flowchart shown in FIG. 9 corresponds to the flow for connecting the input PTF 202-1 for inputting the first fundamental wave light shown in FIG. 6(a). The description will be made while also referring to the configuration of the device shown in FIG. Each step of the flow is explained using step numbers S100 to S116. It should be noted that the description of each step in FIG. 8 is simplified.

In S100, the wavelength conversion module, input PTF 202-1 to be connected,

aligners

203 and 204, etc. are set in the adjustment jig of the manufacturing equipment.

In S101, initial data is read into the computer 208 and the fundamental wave light from the light source 201 is set to the operating wavelength. Further, the wavelength conversion element is set to the initial temperature T _init in the initial data. After a certain temperature stabilization time, the wavelength conversion element reaches the initial temperature T _init , and the initial temperature T _init becomes the "current temperature." The "current temperature" will be updated every time the "step of correcting the current temperature" is repeated, as will be described later.

The input PTF 202-1 is aligned by the detector 207 so that the level of the transmitted light 212 of the fundamental wave light is maximized. Alignment to maximize the level of transmitted light is performed by

aligners

203, 204 and can be performed under processor control using appropriate control algorithms. The fundamental wave light from the end face of the PTF 202-1 is optically coupled to the wavelength conversion element inside the module housing via the lens 205-1. As shown as the transmitted light 10 in FIG. 3, the transmitted light level of the fundamental wave light has almost no wavelength dependence and has very little temperature dependence. It is sufficient to set the light source wavelength to a wavelength near the operating wavelength. Note that this alignment step is performed on fundamental wave light.

Next, in S102, the light source 201 is controlled to wavelength sweep the input light in a predetermined wavelength range centered on the fundamental wave light. The predetermined wavelength range may be determined so that the peak wavelength of the SHG light can be observed, taking into consideration the variation in the phase matching wavelength of the SGH light that is assumed in the wavelength conversion element due to the chip fixing process. At this time, the SHG light detector 206 acquires data on the wavelength dependent characteristic 21 of the SHG light level corresponding to the swept wavelength range as shown in FIG.

Next, in S103, the peak wavelength λ _P is determined from the wavelength dependent characteristics of the acquired SHG light level. This peak wavelength λ _P corresponds to the actual phase matching wavelength at the current temperature of the wavelength conversion element contained within the module. This actual phase matching wavelength is shifted from the operating wavelength λ _init at which the element is originally desired to operate, and the wavelength difference between the peak wavelength λ _P and the operating wavelength λ _init is defined as Δλ. In this step, the wave light sweep by the light source 201 is executed a plurality of times to obtain the average value of the phase matching curve, thereby obtaining the peak wavelength λ _P at which the SHG light output is maximum.

In the state of S103, the wavelength difference Δλ between the peak wavelength λ _P and the operating wavelength λ _init is large, so in many cases, the SHG optical output at a level that allows alignment cannot be obtained. It is difficult to align the input PTF 202-1 so that the level of SHG light is maximized. Therefore, the current temperature of the wavelength conversion element is corrected to obtain a "corrected temperature" so that the wavelength difference Δλ becomes smaller.

In S104, a "corrected temperature" is determined from the wavelength difference Δλ. More specifically, the modified temperature of the wavelength conversion element is determined based on the operating wavelength λ _init of the wavelength conversion element, the above-mentioned peak wavelength λ _P , the current temperature, and the temperature dependence coefficient of the phase matching wavelength included in the initial data. Calculate.

FIG. 9 is a diagram illustrating the principle of determining the corrected temperature of the wavelength conversion element. Similar to FIG. 3, FIG. 9(a) is a diagram illustrating a shift in the phase matching wavelength due to the chip fixing process. The wavelength difference Δλ is the wavelength difference 24 between the peaks of the two

phase matching curves

20 and 21. FIG. 9(b) schematically shows the relationship between the phase matching wavelength (horizontal axis) and the corresponding chip temperature (° C.). The black circle 26 corresponds to a state where the phase matching wavelength is at the operating wavelength λ _init , and this state is the target state. The black circle 27 corresponds to the state where the phase matching wavelength is at the peak wavelength λ _P at the current temperature in S203. In order to bring the current state of the black circle 27 closer to the target state of the target black circle 26, the "current" chip temperature may be corrected by the temperature difference ΔT. By using the value of _the temperature dependence coefficient (nm/° _C ) of the initial data shown in FIG. "Corrected temperature" can be determined. In order to avoid the hunting phenomenon, it is also possible to correct the state 28 to a position before the target state 26. There are no restrictions on the specific algorithm for determining the corrected temperature, and any general control algorithm may be used. Returning to FIG. 9 again, following S104, the wavelength difference Δλ is compared and determined with a reference value.

In S105, the wavelength difference Δλ is compared with a first threshold value, which is a reference value. Since the direction of the wavelength deviation from the initial temperature when the chip is fixed may differ depending on the type of the wavelength conversion element, it is sufficient to compare the absolute value of the wavelength difference Δλ with the positive first threshold value. Here, under the condition that the wavelength difference Δλ is less than or equal to the first threshold value (Y), the actual phase matching wavelength is sufficiently close to the operating wavelength λ _init , so the input PTF realignment process in S108 is performed. move on. Under the condition that the wavelength difference Δλ exceeds the first threshold (N), the actual phase matching wavelength is still far from the operating wavelength λ _init , so the wavelength conversion element is corrected from the current temperature in S106. Set to temperature. After waiting for a certain temperature stabilization time, the procedure of the manufacturing method returns to the step of wavelength sweeping the fundamental wave light in S102. When the process returns to S102, the "corrected temperature" becomes the "current temperature."

The entire process from S102 to S106 described above can also be said to be a process of correcting the current temperature of the wavelength conversion element. The step of determining the reference value in S105 can also be performed before S104 in which the corrected temperature is calculated. Further, in parallel with obtaining the "corrected temperature", the temperature dependence coefficient can also be updated in S107.

At S107, the temperature dependence coefficient is updated based on the operating wavelength, peak wavelength, current temperature, and revised temperature. As shown in FIG. 9(b), the temperature dependence coefficient of the phase matching wavelength can be determined from the wavelength difference Δλ and the temperature difference ΔT, so the temperature dependence coefficient included in the initial data shown in FIG. 13 is updated. Then, using the new temperature dependent coefficient, the steps from S102 to S106 when returning can be carried out.

In S108, the light source 201 is set to the operating wavelength, and the input PTF 202-1 is aligned again using the electric signal from the detector 206 so that the level of the SHG light 213 is maximized. Alignment to maximize the SHG light level is performed by

aligners

203, 204 and can be performed under processor control using appropriate control algorithms. The reason why realignment is performed in S108 even though the alignment to maximize the level of the transmitted light 212 of the fundamental wave light is performed in S101 is as follows.

First, the alignment position where the fundamental wave light output is maximum and the alignment position where the SHG output is maximum may be different. The waveguide mode shape of the fundamental wave light and the waveguide mode shape of the SHG light may not match depending on the core size. Second, after the corrected temperature is set in S106, if S108 is reached after repeating S102 to S105, the chip set temperature has changed from the initial temperature. For this reason, the shape of the wavelength conversion element changes slightly, and there is a possibility that it deviates from the optimal position aligned with the fundamental wave light. For the above-mentioned reasons, in addition to the alignment to maximize the level of the transmitted fundamental light 212 in S101, the input PTF 202-1 is realigned in S108 so as to maximize the SHG output.

Next, in S109, it is determined whether the SHG light level satisfies the reference value. The reference value is a second threshold value which is a predetermined level of SHG light, and if it is equal to or higher than the second threshold value (Y), the process proceeds to the next step S111. If it is less than the second threshold (N), there is a high possibility that there is some kind of defect in the wavelength conversion element itself or in the module assembly process, so further steps are stopped.

In S111, fixing of the metal casing, lens 205-1, and input PTF 202-1 is completed by welding using the YAG laser 209 or the like. The above-mentioned steps S102 to S107 or repetition thereof have been updated to obtain the "corrected temperature", and in the state after being fixed to the module, the phase matching state of the wavelength conversion element is realized at the operating wavelength. are doing. However, YAG welding in S111 may change the charged state of the PPLN element or cause drift during alignment. Furthermore, YAG welding and the fixing work of the input PTF 202-1 may cause the optical axis to shift and the optical coupling rate to decrease.

Therefore, in S112, the fundamental wave light is swept, the peak wavelength λ _P of the SHG light is determined, and the corrected temperature is calculated. Furthermore, in S113, the wavelength difference Δλ is determined based on the reference value (first threshold), and if necessary, the current temperature is changed to the "corrected temperature", and the process returns to the fundamental wave light sweep in S112. . As explained in S107, the temperature dependence coefficient can also be updated. The steps S112 and S113 are simplified descriptions of a series of steps S102 to S107, and substantially the same steps as S102 to S107 may be performed.

In S112, if it is determined that the wavelength difference Δλ is less than or equal to the first threshold, the manufacturing method proceeds to S113, where the transmission spectrum of the fundamental wave light and the phase matching curve are obtained.

Next, in S114, the initial data is updated by the values that have been changed up to the step of S113 described above among the initial data read by the computer 208. Specifically, the initial temperature value is rewritten as shown in FIG. 13(b) using the corrected final temperature value. Furthermore, the value of the temperature dependence coefficient is rewritten by the last value of the corrected temperature dependence coefficient. Once the initial data is updated, the procedure of the wavelength conversion module manufacturing method in FIG. 8 ends in S116.

Therefore, the present invention is a method of manufacturing an optical module 100 including a wavelength conversion element 102 and a temperature control element 103 fixed to the wavelength conversion element via a metal plate 104, in which the wavelength conversion element is adjusted to an initial temperature of a step S101 of aligning the input fiber so that the transmitted light of the fundamental wave light is maximized; and a step S101 of correcting the current temperature of the wavelength conversion element, the step S101 comprising adjusting the current temperature of the wavelength conversion element, Step S103 of sweeping the wavelength of the wave light to determine the peak wavelength at which the level of the wavelength-converted light is maximum, the operating wavelength of the wavelength conversion element, the peak wavelength, the current temperature, and the temperature dependence coefficient of the phase matching wavelength. a step S104 of calculating a corrected temperature of the wavelength conversion element based on the corrected temperature; and a step S106 of resetting the wavelength conversion element to the corrected temperature; , step S108 of realigning the input fiber so that the level of the wavelength-converted light is maximized, and step S111 of fixing the aligned input fiber to the metal casing of the optical module. It can be implemented as a method.

The updated data can be used as initial data in the process of connecting the second and subsequent PTFs to the same wavelength conversion element. That is, in the connection process shown in FIGS. 6(b) to 6(d), by using the "update data" that reflects the results of the connection process of the first PTF, the operating wavelength can be changed from a state very close to the operating wavelength λ _init . , you can start optimizing the chip operating temperature. The process of connecting the second and subsequent PTFs can be carried out in a significantly shorter time than the process of connecting the first PTF shown in FIG.

FIG. 10 is a diagram showing another configuration of an apparatus that implements the method for manufacturing a wavelength conversion module of the present disclosure. The device configuration in FIG. 10 shows the stage of connecting the second input PTF 202-2 shown in FIG. 6(b) to the optical window 105-2 (port 3), and ) is already connected to the input PTF 202-1. A connector-type fundamental wave light detector 210 and a SHG light 213 detector 206 connected to the input PTF 202-1 are used. The flow of the manufacturing method for connecting the second input PTF using the configuration of the manufacturing apparatus shown in FIG. 10 is generally the same as that shown in FIG. 8. The difference is that the initial data read in S101 is not the initial data according to Table 1 of FIG. 13(a) but the updated data according to Table 2 of FIG. The point is that the direction is exactly opposite to that in FIG. Therefore, a description of the method for manufacturing the wavelength conversion module for connecting the second input PTF will be omitted.

FIG. 11 is a diagram showing still another configuration of an apparatus that implements the method for manufacturing a wavelength conversion module of the present disclosure. The device configuration in FIG. 11 shows the stage where the output PTF 202-2, which is the third fiber shown in FIG. 6(c), is connected to the optical window 101-1 (port 4). PTFs 202-1 and 202-2 are connected. A connector type SHG light detector 212 is used on the opposite side of the connection point of the output PTF 211-1. The flow of the manufacturing method for connecting the output PTF according to the configuration of the manufacturing apparatus shown in FIG. 11 is generally the same as that shown in FIG. 8 except that the fiber to be aligned is the output PTF.

FIG. 12 is a flow diagram illustrating the steps of the method for manufacturing a wavelength conversion module of the present disclosure. The flow diagram shown in FIG. 12 corresponds to the flow for connecting the first output PTF 211-1 for outputting SHG light, which is the third fiber shown in FIG. 6(c). The description will be made while also referring to the configuration of the device shown in FIG. Each step of the flow is explained using step numbers S200 to S216. The description of each step in FIG. 12 is simplified. As mentioned above, the procedure in the flowchart of FIG. 12 is generally the same as the procedure in the flowchart of FIG. 8, and therefore will be explained in a simplified manner.

In S200, the wavelength conversion module, the output PTF 211-1 to be connected, the

aligners

203 and 204, etc. are set in the adjustment jig of the manufacturing device.

In S201, initial data is read into the computer 208 and the fundamental wave light from the light source 201 is set to the operating wavelength. Further, the wavelength conversion element is set to the initial temperature T _init in the initial data. However, this initial temperature T _init is the initial temperature updated in the first fiber connection process. Similar to the flow in FIG. 8, the initial temperature T _init becomes the "current temperature." The "current temperature" will be updated every time the "step of correcting the current temperature" is repeated, as will be described later.

Furthermore, in S201, the output PTF 211-1 is aligned so that the level of the SHG light detected by the detector 212 is maximized. Alignment to maximize the SHG light level is performed by

aligners

203, 204 and can be performed under processor control using appropriate control algorithms. SHG light from the wavelength conversion element inside the module housing is optically coupled to the end face of the output PTF 202-1 via a lens. Even in the main flow of FIG. 12 for connecting the output PTFs, the phase matching curves are shifted as shown in FIG. 3 at the current temperature, but the input PTFs 202-1 and 202-2 for fundamental wave light have already been aligned. and has been fixed. Furthermore, the temperature of the wavelength conversion element is set at the initial temperature T _init updated in the first fiber connection process. Therefore, in S201, enough SHG light is obtained for alignment.

Next, in S202, the light source 201 is controlled to wavelength sweep the input light in a predetermined wavelength range centered on the fundamental wave light. At this time, the SHG light detector 212 acquires data of the wavelength dependent characteristic 21 of the SHG light level corresponding to the swept wavelength range as shown in FIG.

Next, in S203, the peak wavelength λ _P is determined from the wavelength dependent characteristics of the acquired SHG light level. This peak wavelength λ _P corresponds to the actual phase matching wavelength at the current temperature of the wavelength conversion element contained within the module. This actual phase matching wavelength is shifted from the operating wavelength λ _init at which the element is originally desired to operate, and the wavelength difference between the peak wavelength λ _P and the operating wavelength λ _init is defined as Δλ. In this step, the wave light sweep by the light source 201 is executed a plurality of times to obtain the average value of the phase matching curve, and to obtain the peak wavelength λ _P at which the SHG light output is maximum.

In the state of S203, there is a wavelength difference Δλ between the peak wavelength λ _P and the operating wavelength λ _init , so the level of the SHG light is insufficient for accurate alignment. Therefore, the current temperature of the wavelength conversion element is corrected to find a "corrected temperature" that reduces the wavelength difference Δλ.

In S204, a "corrected temperature" is determined from the wavelength difference Δλ. Specifically, the corrected temperature of the wavelength conversion element is determined based on the operating wavelength λ _init of the wavelength conversion element, the above-mentioned peak wavelength λ _P , the current temperature, and the temperature dependence coefficient of the phase matching wavelength included in the initial data. calculate.

By using the values of the temperature dependence coefficient (nm/°C) of the updated initial data shown in FIG. 13(b), the operating wavelength λ _init , the peak wavelength λ _P , the current temperature, the temperature of the phase matching wavelength Based on the dependence factor, a "corrected temperature" can be determined.

Next, in S205, the wavelength difference Δλ is compared with a first threshold value that is a reference value. Since the direction of the wavelength deviation from the initial temperature when the chip is fixed may differ depending on the type of the wavelength conversion element, it is sufficient to compare the absolute value of the wavelength difference Δλ with the positive first threshold value. Here, under the condition that the wavelength difference Δλ is less than or equal to the first threshold value (Y), the actual phase matching wavelength is sufficiently close to the operating wavelength λ _init , so the output PTF realignment step of S208 move on. Under the condition that the wavelength difference Δλ exceeds the first threshold (N), the actual phase matching wavelength is still far from the operating wavelength λ _init , so the wavelength conversion element is corrected from the current temperature in S206. Set to temperature. After waiting for a certain temperature stabilization time, the procedure of the manufacturing method returns to the step of wavelength sweeping the fundamental wave light in S202. When the process returns to S202, the "corrected temperature" becomes the "current temperature."

The entire process from S202 to S206 described above can also be called a process of correcting the current temperature of the wavelength conversion element. The step of comparing and determining the reference value in S205 can also be performed before S204 in which the corrected temperature is calculated. Further, in parallel with determining the "corrected temperature", the temperature dependence coefficient can also be updated in S207.

At S207, the temperature dependence coefficient is updated based on the operating wavelength, peak wavelength, current temperature, and modified temperature. The temperature dependence coefficient included in the updated initial data shown in FIG. 13(b) can be updated, and the steps from S202 to S206 upon return can be carried out using the new temperature dependence coefficient.

In S208, the light source 201 is set to the operating wavelength, and the output PTF 211-1 is aligned again using the electrical signal from the detector 212 so that the level of the SHG light is maximized. Alignment to maximize the SHG light level is performed by

aligners

203, 204 and can be performed under processor control using appropriate control algorithms. In addition to performing alignment to maximize the level of the SHG light in S201, re-aligning the output PTF in S208 is similar to the flow for connecting the input PTF in FIG. 8. After the corrected temperature is set in S206, if S208 is reached after repeating S202 to S205, the chip set temperature has changed from the initial temperature. This is because the shape of the wavelength conversion element may change slightly, and the output PTF may deviate from the optimal position initially aligned in S201.

Next, in S209, it is determined whether the SHG light level satisfies the reference value. The reference value is a second threshold value which is a predetermined level of SHG light, and if it is equal to or higher than the second threshold value (Y), the process proceeds to the next step S211. If the SHG light level is less than the second threshold (N), there is a high possibility that there is some kind of defect in the wavelength conversion element itself or in the module assembly process, so further steps are stopped.

In S211, fixing of the metal housing, lens, and output PTF 211-1 is completed by welding using the YAG laser 209 or the like. The "corrected temperature" is obtained by performing the steps S202 to S207 described above or repeating these steps, and the current temperature is updated with the corrected temperature. By using the "corrected temperature," a phase-matched state is achieved at the target operating wavelength λ _init even after it is fixed to the module. However, due to the YAG welding step in S211, the charged (pyroelectric) state of the PPLN element may change or a wavelength may drift during alignment. Furthermore, the optical axis may shift due to YAG welding and the fixing work of the output PTF 211-1, and the optical coupling rate may decrease.

Therefore, in S212, the fundamental wave light is swept, the peak wavelength λ _P of the SHG light is determined, and the corrected temperature is calculated. Furthermore, in S213, the wavelength difference Δλ is compared with a reference value (first threshold), and if necessary, the current temperature is changed to a "corrected temperature", and the fundamental wave light sweep in S212 is performed. return. As explained in S207, the temperature dependence coefficient can also be updated in S213. The steps S212 and S213 are simplified descriptions of a series of steps S202 to S207, and substantially the same steps as S202 to S207 may be performed.

In S213, if it is determined that the wavelength difference Δλ is less than or equal to the first threshold, the manufacturing method proceeds to S214 to acquire the transmission spectrum of the fundamental wave light and the phase matching curve.

Next, in S215, the initial data is updated by the values that have been changed up to the step of S213 described above among the initial data read by the computer 208. Specifically, the initial temperature value is rewritten as shown in FIG. 13(b) using the corrected final temperature value. Once the initial data is updated, the procedure of the wavelength conversion module manufacturing method of FIG. 12 ends in S216.

Therefore, the present invention provides an optical module 100 that includes a wavelength conversion element 102 and a temperature control element 103 fixed to the wavelength conversion element via a metal plate 104, and is connected to a fundamental wave input fiber 211-1. The method includes the steps of setting the wavelength conversion element to an initial temperature, aligning the output fiber so that the transmitted light of the fundamental wave light is maximized, and correcting the current temperature of the wavelength conversion element. A step S203 of sweeping the wavelength of the fundamental light in a predetermined wavelength range to determine a peak wavelength at which the level of the converted wavelength light is maximum, an operating wavelength of the wavelength conversion element, the peak wavelength, a step S204 of calculating a modified temperature of the wavelength conversion element based on the current temperature and a temperature dependence coefficient of the phase matching wavelength; and a step S206 of resetting the wavelength conversion element to the modified temperature. a step S208 of realigning the output fiber so that the level of the wavelength-converted light becomes maximum at the corrected temperature; and a step S208 of realigning the output fiber to the optical module. The manufacturing method can also be implemented as a manufacturing method including step S211 of fixing to a metal casing.

As described in detail above, even when the output PTF is attached to the wavelength conversion module, the "corrected temperature" can be efficiently determined, as in the case where the input PTF is attached to the wavelength conversion module. Once the module, fiber, and alignment member are set in the manufacturing equipment, all processes can be automated and carried out under computer control. To provide a method for manufacturing a pigtail type module with excellent mass productivity through the entire process of attaching fibers to the module.

As already mentioned, FIG. 13 is a diagram illustrating the structure of data of the wavelength conversion element. Table 1 in FIG. 13(a) is initial data obtained in the chip sorting process. FIG. 13(b) shows the updated initial data after the first PTF connection procedure is performed. In the procedure for connecting four PTFs to the wavelength conversion module described with reference to FIG. 6, it is assumed that the updated initial data is used in the procedure for connecting the second and subsequent PTFs.

The initial data may be updated each time the procedure for connecting one PTF is performed, or the same updated initial data may be used for the second to fourth PTFs. By the time the procedure for connecting the first PTF has been performed, the "corrected temperature" is approximately close to the temperature that achieves phase matching at the desired operating wavelength. In the procedure for connecting the third and fourth PTFs, the initial data used in the second PTF can also be used as is.

The method for manufacturing an optical module of the present invention described above is not limited to a wavelength conversion module that outputs SHG light, but can be used when connecting a PTF to an input light port and an output port of wavelength converted light. Furthermore, the present invention can also be applied to a wavelength conversion module that uses a wavelength conversion element in only one direction. Furthermore, it goes without saying that the present invention can also be applied to the case where the PTF is connected to an OPA module using a DFG or OPA mechanism other than a wavelength conversion module.

As explained in detail above, it is possible to realize a method for manufacturing a pigtail type module with excellent mass productivity.

The present invention can be used in manufacturing a device for optical signal processing.

Claims

A method for manufacturing an optical module including a wavelength conversion element and a temperature control element fixed to the wavelength conversion element via a metal plate, the method comprising:
setting the wavelength conversion element to an initial temperature;
aligning the input fiber so that the transmitted light of the fundamental wave light is maximized;
a step of modifying the current temperature of the wavelength conversion element,
Sweeping the wavelength of the fundamental light in a predetermined wavelength range to determine a peak wavelength at which the level of the wavelength-converted light is maximum;
calculating a modified temperature of the wavelength conversion element based on a temperature dependence coefficient of the operating wavelength of the wavelength conversion element, the peak wavelength, the current temperature and the phase matching wavelength;
resetting the wavelength conversion element to the modified temperature;
realigning the input fiber so that the level of the wavelength-converted light is maximized at the modified temperature;
A manufacturing method comprising: fixing the aligned input fiber to a metal casing of the optical module.
Before the re-aligning step,
determining whether an absolute value of a wavelength difference Δλ between the peak wavelength and the operating wavelength is less than or equal to a first threshold;
further comprising repeating the correcting step under the condition that the wavelength difference Δλ exceeds the first threshold;
The manufacturing method according to claim 1, further comprising the step of realigning the input fiber so that the level of the wavelength-converted light is maximized under the condition that the wavelength difference Δλ is equal to or less than the first threshold value. Method.
A method for manufacturing an optical module including a wavelength conversion element and a temperature control element fixed to the wavelength conversion element via a metal plate, and connected to a fundamental wave input fiber, the method comprising:
setting the wavelength conversion element to an initial temperature;
aligning the output fiber so that the transmitted light of the fundamental wave light is maximized;
a step of modifying the current temperature of the wavelength conversion element,
Sweeping the wavelength of the fundamental light in a predetermined wavelength range to determine a peak wavelength at which the level of the wavelength-converted light is maximum;
calculating a modified temperature of the wavelength conversion element based on a temperature dependence coefficient of the operating wavelength of the wavelength conversion element, the peak wavelength, the current temperature and the phase matching wavelength;
resetting the wavelength conversion element to the modified temperature;
realigning the output fiber so that the level of the wavelength-converted light is maximized at the modified temperature;
A manufacturing method comprising: fixing the aligned output fiber to a metal casing of the optical module.
Before the re-aligning step,
determining whether an absolute value of a wavelength difference Δλ between the peak wavelength and the operating wavelength is less than or equal to a first threshold;
further comprising repeating the correcting step under the condition that the wavelength difference Δλ exceeds the first threshold;
The manufacturing method according to claim 3, further comprising the step of realigning the output fiber so that the level of the wavelength-converted light is maximized under the condition that the wavelength difference Δλ is equal to or less than the first threshold value. Method.
After said re-aligning step,
determining whether the level of the wavelength-converted light is equal to or higher than a second threshold;
4. The manufacturing method according to claim 1, further comprising the step of fixing the optical module to a metal casing under the condition that the level of the wavelength-converted light is equal to or higher than the second threshold value.
The modifying step includes:
The manufacturing method according to claim 2 or 4, further comprising: updating the temperature dependent coefficient based on the operating wavelength, the peak wavelength, the current temperature and the modified temperature.
The initial temperature is either a previously obtained initial temperature corresponding to the operating wavelength of the wavelength conversion element or the modified temperature obtained when connecting the input fiber to the optical module. The manufacturing method according to claim 1 or 3.
An optical module manufacturing apparatus including a wavelength conversion element and a temperature control element fixed to the wavelength conversion element via a metal plate,
a light source that supplies fundamental wave light to the optical module;
a first detector that detects wavelength-converted light from the optical module;
a second detector that detects fundamental transmitted light from the optical module;
a centering device for the target fiber;
a computer including at least a processor and memory;
The processor includes:
controlling data conversion of electrical signals from the light source, the first wave detector, and the second wave detector, and the alignment device;
reading element data including at least the operating wavelength, the initial temperature, and the temperature dependence coefficient of the wavelength conversion element from the memory, external storage device, or network, and
configured to update the initial temperature with the modified temperature;
A manufacturing apparatus for carrying out the method according to any one of claims 1 to 4.