JP2003344221A - Semiconductor laser device evaluation method, manufacturing method, and evaluation device - Google Patents

Abstract

An object of the present invention is to provide a method for evaluating a semiconductor laser device capable of measuring a minute change in oscillation wavelength of the semiconductor laser device with time. (A) An evaluation sample is prepared in which a semiconductor laser device under test and a semiconductor laser device for wavelength monitoring are thermally coupled. (B) A drive current is passed through the semiconductor laser device under test, and an oscillation wavelength is measured. (C) A drive current is applied to the wavelength monitoring semiconductor laser device to measure an oscillation wavelength. (D) calculating a difference between the oscillation wavelength of the semiconductor laser device under test measured in the step (b) and the oscillation wavelength of the wavelength monitoring semiconductor laser device measured in the step (c). (E) A driving current flows through the semiconductor laser device to be tested and a driving current does not flow through the wavelength monitoring semiconductor laser device, and this state is maintained for a certain period. (F) After the step (e), the step (b)
To step (e) are repeatedly executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor laser device evaluation method, manufacturing method, and evaluation device, and more particularly to an evaluation method for evaluating the change over time of an oscillation wavelength, an evaluation device, and a semiconductor laser to which the evaluation method is applied. The present invention relates to a method of manufacturing a device.

[0002]

2. Description of the Related Art With the dramatic increase in communication demand in recent years,
By multiplexing multiple optical signals with different wavelengths,
The development of a wavelength division multiplexing (WDM) communication system that enables transmission of a larger capacity with one optical fiber is in progress. WDM
In the communication system, by broadening the wavelength selection range and narrowing the wavelength interval, it is possible to further increase the multiplexing and increase the transmission capacity. For example, when the spacing between the wavelengths of a single longitudinal mode of a plurality of optical signals arranged in the wavelength space is narrowed to about 0.4 nm, a long-term wavelength fluctuation of 0.
High reliability of 1 nm or less is required.

A conventional method for evaluating the wavelength reliability of a semiconductor laser device will be described below. The semiconductor laser device is placed in a thermostatic chamber for acceleration test, and the laser beam emitted from the semiconductor laser device is introduced into the wavelength meter via an optical fiber. The semiconductor laser device is energized to generate laser oscillation, and the wavelength is periodically measured with a wavelength meter. This makes it possible to detect changes in the oscillation wavelength over time.

[0004]

The oscillation wavelength of the semiconductor laser device is very sensitive to the element temperature. For example, if the element temperature fluctuates by about 1 ° C. due to the temperature disturbance in the constant temperature bath, the oscillation wavelength of the distributed feedback Bragg reflection (DFB) type semiconductor laser device fluctuates by about 0.1 nm.

FIG. 5 shows the wavelength variation of the semiconductor laser device measured by the conventional method. The horizontal axis represents the elapsed time in the unit of "time", and the vertical axis represents the fluctuation range of the oscillation wavelength in the unit of "nm". The white circle symbols in the figure show the wavelength variation of one sample, and the white square symbols show the wavelength variation of other samples. In addition,
The measured semiconductor laser device was not energized except when measuring the oscillation wavelength. Therefore, it is considered that the semiconductor laser device to be measured hardly deteriorates with time due to energization.

As shown in FIG. 5, although the semiconductor laser device hardly deteriorates with time, the oscillation wavelength fluctuates within a width of about 0.1 nm. It is considered that this is because the temperature of the semiconductor laser device during wavelength measurement is not constant. Even if the semiconductor laser device is continuously energized for a long time under this condition and the change with time of the oscillation wavelength is measured, it is difficult to detect the wavelength variation of 0.1 nm or less.

An object of the present invention is to provide a method for evaluating a semiconductor laser device, which is capable of measuring a minute change over time in the oscillation wavelength of the semiconductor laser device. Another object of the present invention is to provide a method of manufacturing a semiconductor laser device using the above evaluation method.

Still another object of the present invention is to provide an evaluation device for evaluating a semiconductor laser device by the above evaluation method.

[0009]

According to one aspect of the present invention, (a) a step of preparing an evaluation sample in which a semiconductor laser device under test and a semiconductor laser device for wavelength monitoring are thermally coupled, (b) ) Applying a driving current to the semiconductor laser device under test to measure the oscillation wavelength; (c) Applying a driving current to the wavelength monitoring semiconductor laser device to measure the oscillation wavelength; (d) Calculating a difference between the oscillation wavelength of the semiconductor laser device under test measured in the step (b) and the oscillation wavelength of the semiconductor laser device for wavelength monitoring measured in the step (c); ) A step in which a driving current flows through the semiconductor laser device under test and a driving current does not flow through the semiconductor laser device for wavelength monitoring, and this state is maintained for a certain period, and (f) the step (e)
After that, a method for evaluating a semiconductor laser device is provided, which includes the step of repeatedly executing the step (b) to the step (e).

In the wavelength monitor semiconductor laser device, since no drive current flows during the step (e), deterioration due to energization is small. Since the semiconductor laser device under test and the wavelength monitoring semiconductor laser device are thermally coupled to each other, their temperatures are substantially equal to each other. By taking the difference between the oscillation wavelength of the semiconductor laser device under test and the oscillation wavelength of the semiconductor laser device for wavelength monitoring, the disturbance due to the fluctuation of the wavelength caused by the temperature fluctuation is eliminated, and the deterioration of the semiconductor laser device under test due to the energization over time It is possible to detect fluctuations in the oscillation wavelength due to

According to another aspect of the present invention, a power supply for supplying a drive current to the thermally coupled semiconductor laser device under test and the semiconductor laser device for wavelength monitoring, the semiconductor laser device under test and the wavelength monitor. The semiconductor laser device for use for measuring the wavelength of the laser light emitted from, and the wavelength measurement result by the wavelength meter is input, and has a control device for controlling the power supply, the control device, g) a step of controlling the power supply so that a drive current flows through the semiconductor laser device under test and storing the oscillation wavelength of the semiconductor laser device under test measured by the wavelength meter, and (h) for wavelength monitoring Controlling the power supply so that a drive current flows through the semiconductor laser device and storing the oscillation wavelength of the wavelength monitoring semiconductor laser device measured by the wavelength meter; Calculating a difference between the oscillation wavelength of the semiconductor laser device under test stored in (g) and the oscillation wavelength of the semiconductor laser device for wavelength monitoring stored in step (h); A step in which a driving current flows through the semiconductor laser device under test, a driving current does not flow through the semiconductor laser device for wavelength monitoring, and the power supply is controlled so that this state is maintained for a certain period; and (k) the step An evaluation apparatus for a semiconductor laser device is provided, which controls the power supply and the wavelength meter so that the steps (g) to (j) are repeatedly performed after (j).

With this evaluation apparatus, the semiconductor laser device can be evaluated by using the above-described semiconductor laser device evaluation method.

[0013]

1 is a schematic diagram of an evaluation apparatus for a semiconductor laser device according to a first embodiment of the present invention. A coupling member (carrier) 2 made of, for example, a copper-tungsten (CuW) alloy is placed in a constant temperature bath 1. The semiconductor laser device 10S under test is attached to the coupling member 2 via the heat sink 11S, and the semiconductor laser device 10R for wavelength monitoring is attached via the heat sink 11R. The coupling member 2 includes heat sinks 11S and 1S.
The semiconductor laser device 10S to be tested and the wavelength monitoring semiconductor laser device 10R are thermally coupled via 1R. Therefore, the temperature of the semiconductor laser device under test 10S and the temperature of the wavelength monitoring semiconductor device 10R are kept substantially the same.

Power supplies 3S and 3R supply drive currents to the semiconductor laser device 10S under test and the semiconductor laser device 10R for wavelength monitoring, respectively. The controller 5 controls the supply and stop of the drive current by the power supplies 3S and 3R. The laser beam emitted from the semiconductor laser device 10S under test is introduced into the wavelength meter 4S via the optical fiber 12S, and the laser beam emitted from the wavelength monitoring semiconductor laser device 10R passes through the optical fiber 12R. It is introduced into the wavemeter 4R.

The wavelength meters 4S and 4R measure the wavelengths of the laser beams emitted from the semiconductor laser device 10S under test and the semiconductor laser device 10R for wavelength monitoring, respectively,
The measurement result is transmitted to the control device 5.

In FIG. 2, measurement was carried out using the evaluation device of FIG.
The fluctuation amount of the oscillation wavelength is shown. The horizontal axis represents the elapsed time in hours
And the vertical axis represents the semiconductor laser device 10S under test.
The oscillation wavelength is λ_S, Wavelength monitoring semiconductor laser device 10R
The oscillation wavelength of_RAnd then λ _S−λ_RUnit is "nm"
It is represented by. Note that the semiconductor under test is
Laser device 10S and wavelength monitor semiconductor laser device 1
No drive current was applied to 0R.

As shown in FIG. 2, the wavelength fluctuation range is about 0.0.
It can be seen that the thickness is 1 nm or less. When the temperature of the semiconductor laser device 10S under test changes, the temperature of the wavelength monitoring semiconductor laser device 10R also changes. By taking the difference between the oscillating wavelengths of the two, the fluctuation of the oscillating wavelength due to the temperature fluctuation is canceled, so that the wavelength fluctuation width is reduced. In order to effectively cancel the fluctuation of the oscillation wavelength due to the temperature fluctuation, it is preferable that the temperature dependency of the oscillation wavelength of the wavelength monitoring semiconductor laser device 10R is equal to the temperature dependency of the oscillation wavelength of the semiconductor laser device 10S under test. . Also,
More preferably, the structure and material of the wavelength monitoring semiconductor laser device 10R are the same as the structure and material of the semiconductor laser device 10S under test.

Next, using the evaluation apparatus shown in FIG.
A method for measuring the change with time of the oscillation wavelength of the semiconductor laser device 10S under test will be described. The temperature in the constant temperature bath 1 is
A predetermined temperature is set according to the conditions of the accelerated test.

FIG. 3A shows a semiconductor laser device 1 under test.
An example of a timing chart of the drive current of the semiconductor laser device 10R for 0S and wavelength monitoring is shown. A constant drive current is constantly applied to the semiconductor laser device 10S under test. This drive current is controlled by automatic power control (APC: Auto).
Power Control) or automatic current control (ACC: Auto Current Control)
It is set corresponding to the accelerated deterioration condition of l). A drive current is passed through the wavelength monitoring semiconductor laser device 10R only when measuring the oscillation wavelength (time t ₀ , t ₁ , t ₂ , t ₃ ...). The oscillation wavelength is measured, for example, every 2 hours to 500 hours. The oscillation wavelength measurement time is about several minutes. The measurement time of the oscillation wavelength is sufficiently shorter than the measurement interval of the oscillation wavelength. Therefore, the wavelength monitor semiconductor laser device 10R
It is considered that there is almost no deterioration with time.

The oscillation wavelengths of the semiconductor laser device 10S under test and the semiconductor laser device 10R for wavelength monitoring are set at the same time.
Or measure at almost the same time. The measurement of the oscillation wavelength is performed after the supply of the drive current to the wavelength monitoring semiconductor laser device 10R is started and the element temperature is stable. It takes about several minutes from the start of supplying the drive current until the element temperature becomes stable. Oscillation wavelength λ of semiconductor laser device 10S under test
By calculating the difference between the oscillation wavelength of _S and the wavelength monitoring semiconductor laser device 10R and λ _R , fluctuations in the oscillation wavelength due to temperature fluctuations are eliminated, and the semiconductor laser device under test 10
It is possible to detect fluctuations in the oscillation wavelength due to deterioration over time due to the energization of S.

FIG. 3B shows a semiconductor laser device 1 under test.
Driving power for the semiconductor laser device 10R for 0S and wavelength monitoring
Another example of a flow timing chart is shown. Half for wavelength monitor
The conductor laser device 10R is similar to the case of FIG.
At the time of measuring the oscillation wavelength (time t ₀, T₁, T₂, T₃・ ・
・ Drive current is sent only to (). Semiconductor monitor for wavelength monitor
Just before the drive current is passed to the laser device 10R
The supply of the drive current to the laser device 10S is stopped. wave
For measuring the oscillation wavelength of the long monitor semiconductor laser device 10R
Completion and driving to the wavelength monitor semiconductor laser device 10R
Immediately after stopping the current supply, the semiconductor laser device under test is
The supply of the drive current to the device 10S is restarted.

The oscillation wavelength of the semiconductor laser device 10S under test is measured immediately before the supply of the drive current is stopped or after the supply of the drive current is restarted while the element temperature is stable. If the semiconductor laser device 10S under test and the wavelength monitor semiconductor laser device 10R have the same characteristics and the supplied drive currents are equal, the two calorific values are substantially the same. Therefore, the element temperature at the time when the supply of the drive current to the semiconductor laser device 10S under test is stopped is the semiconductor laser device 10R for wavelength monitoring.
It is considered that the element temperature is almost equal to that at the time when the element temperature is stabilized after the supply of the drive current to the element is started. Therefore, the oscillation wavelength of the semiconductor laser device under test 10S and the oscillation wavelength of the wavelength monitoring semiconductor laser device 10R can be measured under substantially the same temperature condition.

As a result, similarly to the method shown in FIG. 3A, the fluctuation of the oscillation wavelength caused by the temperature fluctuation is eliminated, and the oscillation wavelength caused by the deterioration over time due to the energization of the semiconductor laser device 10S under test. Can be detected.

When the semiconductor laser device 10S under test deteriorates, its heat generation characteristics may change. Figure 3
In the method shown in (B), the semiconductor laser device 10 to be tested is
It is possible to measure the oscillation wavelength of the wavelength monitoring semiconductor laser device 10R without being affected by the change in the heat generation characteristic of S.

Next, a method for manufacturing a semiconductor laser device using the above-described method for evaluating a semiconductor laser device will be described.
First, a plurality of semiconductor laser devices before inspection are prepared. The evaluation method according to the first embodiment is performed on the prepared plurality of semiconductor laser devices. The evaluation time is set according to the life required for the device, acceleration conditions, and the like. The maximum value of the measured wavelength fluctuation amount is compared with a predetermined reference value. If the maximum value of the wavelength fluctuation amount is equal to or less than the reference value, the semiconductor laser device is accepted, and if it is larger than the reference value, the semiconductor laser device is rejected.

By determining pass / fail of the semiconductor laser device by using the evaluation method according to the first embodiment, it is possible to ensure that the wavelength variation amount of the semiconductor laser device is equal to or less than the reference value.

Next, with reference to FIG. 4, an evaluation apparatus and an evaluation method according to the second embodiment will be described. Figure 4 (A)
FIG. 7 shows a schematic plan view of a semiconductor laser device evaluated by the method according to the second embodiment. The semiconductor laser device evaluated by the method according to the second embodiment has a plurality of equivalent light emitting regions 2.
0 is an array type semiconductor laser device having 0.

FIG. 4B shows a schematic diagram of an evaluation device used in the method according to the second embodiment. The array type semiconductor laser device 10 includes a carrier 2 and a carrier 2 via a heat sink 11.
Held in. The carrier 2 is arranged in the constant temperature bath 1. One of the plurality of light emitting regions 20 of the array type semiconductor laser device 10 is selected, and the selected light emitting region 20 is selected.
Is a light emitting region for wavelength monitoring. Further, another one light emitting region 20 is set as a light emitting region to be tested. The test light emitting region and the wavelength monitor light emitting region correspond to the test semiconductor laser device 10S and the wavelength monitor semiconductor laser device 10R used in the method according to the first embodiment, respectively. Since the light emitting region under test and the light emitting region for wavelength monitoring are formed on one substrate, they are thermally coupled.

The power supplies 3S and 3R supply drive currents to the light emitting region under test and the light emitting region for wavelength monitoring, respectively.
The controller 5 controls the supply and stop of the drive current by the power supplies 3S and 3R. The laser beam emitted from the light emitting region under test and the light emitting region for wavelength monitoring is introduced into the wavelength meter 4 via the condensing optical element 21 and the optical fiber 12. The wavelength meter 4 measures the wavelength of the laser beam emitted from the light emitting region under test or the light emitting region for wavelength monitoring, and transmits the measurement result to the control device 5.

In the evaluation method according to the second embodiment, as shown in FIG.
Based on the timing chart shown in (B), it is possible to measure the fluctuation of the oscillation wavelength of the light emitting region to be tested by supplying a drive current to the light emitting region to be tested and the light emitting region for wavelength monitoring.

The present invention has been described above with reference to the embodiments.
The present invention is not limited to these. For example, it will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

The inventions shown in the following supplementary notes are derived from the above embodiments. (Supplementary Note 1) (a) a step of preparing an evaluation sample in which the semiconductor laser device under test and the semiconductor laser device for wavelength monitoring are thermally coupled, and (b) a drive current is passed through the semiconductor laser device under test. The step of measuring the oscillation wavelength, (c)
Measuring the oscillation wavelength by supplying a driving current to the wavelength monitor semiconductor laser device; and (d) the step (b).
Calculating the difference between the oscillation wavelength of the semiconductor laser device under test measured in step (c) and the oscillation wavelength of the wavelength monitoring semiconductor laser device measured in step (c),
(E) A drive current flows through the semiconductor laser device under test,
A step in which a drive current does not flow in the wavelength monitor semiconductor laser device, and this state is maintained for a certain period;
(F) A method of evaluating a semiconductor laser device, which comprises the step (e) and the step (e) repeatedly performed after the step (e).

(Supplementary Note 2) The method for evaluating a semiconductor laser device according to Supplementary Note 1, wherein a driving current is continuously supplied to the semiconductor laser device under test during the steps (b) to (f).

(Supplementary Note 3) In the above-mentioned step (c), energization to the semiconductor laser device under test is stopped while a drive current is being supplied to the semiconductor laser device for wavelength monitoring. Evaluation method of semiconductor laser device.

(Supplementary Note 4) The evaluation sample prepared in the step (a) is an array type semiconductor laser device including a plurality of light emitting regions formed on one substrate, and the semiconductor laser device to be tested. And the semiconductor laser device for wavelength monitoring is one semiconductor laser device selected from a plurality of light emitting regions forming the array type semiconductor laser device. Method.

(Supplementary note 5) Supplementary notes 1 to 4 further including a step of comparing the difference calculated in the step (d) with a reference value.
7. A method for evaluating a semiconductor laser device according to any one of 1. (Supplementary Note 6) The step of preparing a plurality of semiconductor laser devices before inspection, the evaluation method of claim 5 is performed for the plurality of semiconductor laser devices, and the difference calculated in the step (d) is a reference value. A method of manufacturing a semiconductor laser device, comprising the steps of passing the following semiconductor laser device and rejecting a semiconductor laser device larger than a reference value.

(Supplementary Note 7) A power source for supplying a drive current to the semiconductor laser device under test and the semiconductor laser device for wavelength monitoring, which are thermally coupled, the semiconductor laser device under test, and the semiconductor laser device for wavelength monitoring. A wavelength meter for measuring the wavelength of the laser beam emitted from the device, and a control device for controlling the power source by inputting the measurement result of the wavelength by the wavelength meter, wherein the control device is (g) the device under test. The power supply is controlled so that a driving current flows through the semiconductor laser device,
Storing the oscillation wavelength of the semiconductor laser device under test measured by the wavelength meter, and (h) controlling the power supply so that a driving current flows through the wavelength monitoring semiconductor laser device, Storing the measured oscillation wavelength of the semiconductor laser device for wavelength monitoring, (i) storing the oscillation wavelength of the semiconductor laser device under test stored in step (g), and storing it in step (h). A step of calculating a difference between the oscillation wavelength of the wavelength monitoring semiconductor laser device and (j) a state in which a driving current flows through the semiconductor laser device under test and a driving current does not flow through the wavelength monitoring semiconductor laser device. , A step of controlling the power supply so that this state is maintained for a certain period, and (k) a step of repeatedly executing the steps (g) to (j) after the step (j). Evaluation device for a semiconductor laser device for controlling sea urchin the power and the wavelength meter.

(Supplementary Note 8) During the steps (g) to (k), the control device controls the power supply so that a driving current continuously flows through the semiconductor laser device under test. An evaluation device for a semiconductor laser device according to appendix 7.

(Supplementary Note 9) In the step (h), the control device is controlled so that energization to the semiconductor laser device under test is stopped while a drive current is being supplied to the wavelength monitoring semiconductor laser device. 8. The semiconductor laser device evaluation apparatus according to appendix 7, wherein the power source is controlled.

(Supplementary Note 10) Further, the control device is
10. The semiconductor laser device evaluation apparatus according to any one of appendices 7 to 9, which executes a step of comparing the difference calculated in the step (i) with a reference value.

(Additional remark 11) Furthermore, in any one of the additional remarks 7 to 10, further comprising a holding member for holding the semiconductor laser device under test and the semiconductor laser device for wavelength monitoring so that they are thermally coupled to each other. Evaluation equipment for semiconductor laser devices.

[0042]

As described above, according to the present invention,
Eliminating the influence of oscillation wavelength variation due to element temperature variation,
The semiconductor laser device can be evaluated by highly accurately measuring the fluctuation of the oscillation wavelength caused by the deterioration caused by energization.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an evaluation device used in an evaluation method according to a first embodiment of the present invention.

FIG. 2 is a graph showing a result of measuring a variation in an oscillation wavelength of a semiconductor laser device using the evaluation device shown in FIG.

FIG. 3 is a timing chart of a drive current used in the evaluation method according to the embodiment of the present invention.

FIG. 4 is a schematic plan view of a semiconductor laser device which is a target of an evaluation method according to a second embodiment of the present invention, and a schematic view of an evaluation device used in the evaluation method.

FIG. 5 is a graph showing a result of measuring a variation in oscillation wavelength of a semiconductor laser device using a conventional evaluation device.

[Explanation of symbols]

1 constant temperature bath 2 connecting members 3S, 3R power supply 4, 4S, 4R Wavemeter 5 control device 10 Array type semiconductor laser device 10S Semiconductor laser device under test Semiconductor laser device for 10R wavelength monitor 11, 11S, 11R heat sink 12S, 12R optical fiber 20 light emitting area 21 Condensing optical element

Claims (10)

[Claims] 1. A step of (a) preparing an evaluation sample in which a semiconductor laser device under test and a semiconductor laser device for wavelength monitoring are thermally coupled, and (b) a drive current is passed through the semiconductor laser device under test. Measuring the oscillation wavelength, (c) applying a drive current to the wavelength monitoring semiconductor laser device to measure the oscillation wavelength, and (d) the device under test measured in the step (b). A step of calculating a difference between an oscillation wavelength of the semiconductor laser device and an oscillation wavelength of the wavelength monitoring semiconductor laser device measured in the step (c), and (e) a drive current flows through the semiconductor laser device under test. ,
A step of keeping a driving current in the wavelength monitor semiconductor laser device for a certain period of time, and (f) repeating the steps (b) to (e) after the step (e) And a method of evaluating a semiconductor laser device. 2. Between the step (b) and the step (f),
The method for evaluating a semiconductor laser device according to claim 1, wherein a drive current is continuously supplied to the semiconductor laser device under test. 3. In the step (c), during a period in which a drive current is flowing through the wavelength monitoring semiconductor laser device,
The method for evaluating a semiconductor laser device according to claim 1, wherein energization to the semiconductor laser device under test is stopped. 4. The evaluation sample prepared in the step (a) is an array type semiconductor laser device including a plurality of light emitting regions formed on one substrate, and the semiconductor laser device under test and the wavelength are tested. Each of the monitor semiconductor laser devices,
The semiconductor laser device is one semiconductor laser device selected from a plurality of light emitting regions forming the array type semiconductor laser device.
4. A method for evaluating a semiconductor laser device according to any one of 3 to 3. 5. The method for evaluating a semiconductor laser device according to claim 1, further comprising a step of comparing the difference calculated in step (d) with a reference value. 6. A step of preparing a plurality of semiconductor laser devices before inspection, a method of carrying out the evaluation method of claim 5 with respect to the plurality of semiconductor laser devices, and a difference calculated in the step (d) is a reference. A method of manufacturing a semiconductor laser device, which comprises: passing a semiconductor laser device having a value equal to or less than a value, and rejecting a semiconductor laser device having a value larger than a reference value. 7. A power source for supplying a drive current to the semiconductor laser device under test and the semiconductor laser device for wavelength monitoring, which are thermally coupled, and the semiconductor laser device under test and the semiconductor laser device for wavelength monitoring. A wavelength meter for measuring the wavelength of the laser light to be generated, and a control device for controlling the power source by inputting the measurement result of the wavelength by the wavelength meter, wherein the control device comprises: (g) the semiconductor laser under test Controlling the power supply so that a drive current flows through the device, and storing the oscillation wavelength of the semiconductor laser device under test measured by the wavelength meter, and (h) applying a drive current to the wavelength monitoring semiconductor laser device. Controlling the power supply so as to flow, and storing the oscillation wavelength of the wavelength monitoring semiconductor laser device measured by the wavelength meter, (i) before storing in step (g) The step of calculating a difference between the oscillation wavelength of the semiconductor laser device under test and the oscillation wavelength of the semiconductor laser device for wavelength monitoring stored in the step (h), and (j) driving the semiconductor laser device under test. Current flows,
A step in which a drive current does not flow through the wavelength monitoring semiconductor laser device and the power source is controlled so as to maintain this state for a certain period of time; (k) after the step (j), the step (g) To the step of repeatedly performing step (j) to step (j), the semiconductor laser device evaluation apparatus for controlling the power supply and the wavelength meter. 8. Between the steps (g) and (k),
The semiconductor laser device evaluation apparatus according to claim 7, wherein the control device controls the power supply so that a drive current continuously flows through the semiconductor laser device under test. 9. In the step (h), during a period in which a drive current is flowing through the wavelength monitoring semiconductor laser device,
The evaluation device for a semiconductor laser device according to claim 7, wherein the control device controls the power supply so that the power supply to the semiconductor laser device under test is stopped. 10. The evaluation apparatus for a semiconductor laser device according to claim 7, wherein the control device further executes a step of comparing the difference calculated in the step (i) with a reference value. .