JP2007096076A - Semiconductor laser evaluation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor laser evaluation apparatus capable of efficiently evaluating characteristics of a semiconductor laser such as a laser coupler from the standpoint of parameters employing its operating temperature. <P>SOLUTION: The semiconductor laser evaluation apparatus is provided with: an electric circuit for driving the laser coupler 10 and provided with a socket 20, an LDD board 52, and a control board 51; and a temperature control unit 30 including a temperature sensor 31 for obtaining temperature information of the laser coupler 10, and a temperature control circuit 32 for regulating the temperature of a hot plate 34, by using the temperature information by way of an exothermic/endothermic element 33 such as a peltier element. A heat transmission member 18 is located between the hot plate 34 and the laser coupler 10 while thermally coupling to them, and the temperature sensor 31 is located closest to the laser coupler 10. Thus, the temperature of the laser coupler 10 is quickly stabilized to a prescribed temperature with high accuracy, and prescribed characteristics of the laser coupler 10 can be obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor laser evaluation apparatus for evaluating characteristics of an electronic component whose operating characteristics change depending on temperature conditions, such as a semiconductor laser for an optical pickup, using the operating temperature as a parameter.

  In recent years, semiconductor lasers have become increasingly important as key devices in the field of optical information processing using optical disc recording media represented by optical communication, CD (Compact Disc), DVD (Digital Versatile Disc), etc. Various products according to the application are provided by manufacturers.

An example of the structure of a semiconductor laser for picking up an optical disk conventionally used will be described with reference to FIG.
The conventional semiconductor laser 200 has a so-called metal can package in which a laser chip is mounted on a heat sink inside a metal cap 200a. As shown in FIG. 12A, a laser with a cover glass is formed on the top of the cap 200a. A light exit window 200b is formed. A lead pin 200d extends from the lower surface of the stem 200c provided at the lower portion of the cap 200a.

  As described above, since the heat generated in the laser chip can be quickly transferred to the heat sink, cap, stem, and lead pin, for example, the socket 201 with the semiconductor laser 200 mounted as shown in FIG. 12B. Is attached to the attachment jig 202, and the attachment jig 202 is attached to a heat radiating plate or the like, so that the temperature of the operating laser chip can be relatively easily kept within a predetermined temperature and stable operation can be performed.

By the way, it is necessary to evaluate the characteristics of this type of semiconductor laser during development.
For example, in general, in a semiconductor laser chip, when the input current exceeds a predetermined value, the amount of heat generated from the element itself exceeds the amount of heat dissipation, and the laser beam emission output decreases due to excessive temperature rise of the element itself. FIG. 13 shows light output characteristics (IL characteristics) with respect to forward current when the input current (mA) is gradually increased without fixing the semiconductor laser to a heat sink or the like. It can be seen that the output decreases when the value is exceeded.
For this reason, in semiconductor lasers mounted on various devices, it is important to clearly set the stable operation region, and it is necessary to clarify various characteristics using the temperature during operation of the semiconductor laser as a parameter. .

As a technique for accurately grasping the characteristics of a semiconductor laser whose characteristics greatly vary depending on the temperature, a technique disclosed in Patent Document 1 has been known.
This Patent Document 1 discloses a method and an apparatus for measuring temperature dependence of optical characteristics in a semiconductor laser. This method of measuring the temperature dependence of the optical characteristics of the semiconductor laser is such that when one or more of the characteristics of the semiconductor laser substantially exceed predetermined upper and lower limits while continuously changing the temperature, The measurement is continuously performed over a predetermined temperature range while reversing the direction of the continuous change in the power output of the semiconductor laser.
Japanese Patent Laid-Open No. 63-27727 (FIG. 1)

  Now, the semiconductor laser chip and peripheral devices are integrated so that the mounting space is more compact and the equipment can be easily adjusted, compared to the metal can package type where the semiconductor laser is used alone. Laser couplers, which are integrated optical integrated devices, are becoming widespread.

  8A and 8B are external perspective views of an example of a laser coupler. As shown in FIG. 8A as viewed obliquely from above, the laser coupler 10 has an optical integrated device 100 mounted on a die plate 15, and the optical integrated device 100. A cover 16 having an opening is provided so as to cover.

As shown in FIG. 9 which is an external perspective view and FIG. 10 which is a side sectional view, this optical integrated device 100 has an optical microprism 102 and a semiconductor laser 104 mounted on a photodiode 103 on a photodetector IC101. In addition, so-called LOP (Laser on Photodiode) chips are mounted adjacent to each other.
The photo-detector IC 101 includes a pair of photodiodes PD1 and PD2 for detecting an optical signal, a current-voltage (IV) conversion amplifier and an arithmetic processing unit (both of output current signals from the photodiodes PD1 and PD2). (Not shown) is an IC. Here, as the photodiodes PD1 and PD2, for example, those obtained by dividing each photodiode into four parts are used, and as shown in FIG. 10, the surface of the photodiodes PD1 and PD2 is a silicon nitride (SiN) film or silicon oxide. The half mirror layer 110 is covered with a (SiO ₂ ) film or the like.

As shown in FIG. 10, the optical microprism 102 has an inclined surface 102a, a top surface 102b, a bottom surface 102c, an end surface 102d, and an end surface 102e that serve as a light incident surface. The half mirror 105 is formed on the inclined surface 102a, the total reflection film 106 is formed on the upper surface 102b, the end surface 102d on the LOP chip side is configured as a mirror surface, and the light absorbing film is formed on the end surface 102e opposite to the LOP chip. 107 is formed.
Further, an antireflection film 108 is formed on the entire bottom surface 102c of the optical microprism 102, and the optical microprism 102 thus formed is formed on the surface of the photo detector IC101 where the photodiodes PD1 and PD2 are formed. It is mounted by being bonded via an adhesive layer 109 made of resin or the like.
The photodiode 103 is for monitoring the light output from the rear end face of the semiconductor laser 104 and thereby monitoring the light output from the front end face, so-called rear APC (Auto Power Control). ) Light output control using a driving method is performed.

The die plate 15 is made of a substantially rectangular ceramic wiring board. As shown in FIG. 8B, the die plate 15 is formed on a surface opposite to the mounting surface of the optical integrated device 100 with a metal film for releasing heat generated in the optical integrated device 100. The die pad 15a and a plurality of lands 15b, 15b,... That are electrically connected to the optical integrated device 100 through buried vias and inner wiring layers are provided on the three sides around the die pad 15a.
As shown in FIG. 8A, the cover 16 is provided with an upper emission window 16 a and openings 16 b and 16 c that are heat radiation windows with respect to the optical integrated device 100.
Then, using the concave portions provided in the two short sides shown in FIG. 8A of the substantially rectangular die plate 15, the optical integrated device 100 is mounted at a predetermined position with the die plate 15 positioned, and The cover 16 is provided at a predetermined position that does not block the laser light emitted from the optical integrated device 100 or the light reflected and returned from the optical disc, and the laser coupler 10 is assembled.

The operation of the thus configured laser coupler 10 will be described with reference to FIGS. In FIG. 11, only the part of the optical integrated device 100 which is a main part is shown.
Laser light L emitted from the front end face of the semiconductor laser 104 of the optical integrated device 100 is reflected by the half mirror 105 (FIG. 10) on the inclined surface 102a of the optical microprism 102 and then condensed by the objective lens OL. Then, the light enters the disk D from which a signal is read. The laser light L reflected by the disk D enters the inside of the optical microprism 102 through the half mirror 105 (FIG. 10) on the inclined surface 102a of the optical microprism 102. Half (50%) of the light entering the inside of the optical microprism 102 is incident on the photodiode PD1, and the remaining half (50%) of light is a half mirror layer formed on the photodiode PD1. 110 (FIG. 10) and the upper surface 102b of the optical microprism 102 are sequentially reflected and enter the photodiode PD2.

The laser coupler 10 is designed so that the spot sizes on the front and rear photodiodes PD1 and PD2 are the same when the laser beam L is focused on the recording surface of the disk D.
For this reason, when the focal position deviates from the recording surface due to the undulation of the optical disk D surface, the spot sizes on the photodiodes PD1 and PD2 are different from each other. The focus error signal can be detected by making the difference between the output signal from the photodiode PD1 and the output signal from the photodiode PD2 correspond to the shift of the focal position.
The zero point of the focus error signal corresponds to the point where the focal position coincides with the recording surface of the disk D, that is, the just focus point, and feedback is given to the focus servo system so that the focus error signal becomes zero. In this way, the just focus state is maintained, and the reproduction of the disk D is performed without any trouble.

  Although it is necessary to clearly and accurately evaluate the operating characteristics including the operating margin of such a laser coupler, the conventional metal can package is different not only in shape but also in mounting form. Cannot be used.

  In view of this point, the present invention has an operation of a semiconductor laser of a laser coupler for an optical pickup, for example, in which a heating element is mounted on one side of a package base, and a heat radiation part is provided on the other side and its operating characteristics change depending on temperature conditions The present invention proposes a semiconductor laser evaluation apparatus capable of efficiently evaluating characteristics using the time temperature as a parameter.

  In order to solve the above problems, the present invention has a characteristic detection unit and a component drive unit, and in the semiconductor laser evaluation apparatus for evaluating the characteristics of a semiconductor laser having a heat dissipation unit on one surface of a package base, the component drive unit includes: A component drive board on which an electronic circuit for driving the semiconductor laser is mounted, a control board for controlling the component drive board, and an electrical contact terminal of the connection terminal of the semiconductor laser are provided, and the contact terminal is the component drive board The socket is extended so that it can be electrically connected to the connection terminal of the semiconductor device, supports the semiconductor laser in a detachable manner, has a through-hole at a position corresponding to the heat radiating portion, a heat plate, and controls the temperature of the heat plate. And a heat transfer member provided on the hot plate as well as having a protrusion inserted into the through hole of the socket.

  According to the semiconductor laser evaluation apparatus configured as described above, the protruding portion of the heat transfer member comes into contact with the heat radiating portion of the semiconductor laser, and the heat generated by the semiconductor laser is radiated to the heat plate via the heat transfer member. The Then, the temperature of the semiconductor laser is adjusted so as to be close to the set temperature of the hot plate.

  According to the semiconductor laser evaluation apparatus of the present invention, a heat generating element is mounted on one surface of a package base, and a heat radiation portion is provided on the other surface, and its operating characteristics change depending on temperature conditions. The input / output characteristics using the operating temperature as a parameter can be evaluated efficiently and accurately.

An example of an embodiment of the present invention will be described with reference to FIGS.
In this embodiment, a laser coupler for an optical pickup is used as an example of a semiconductor laser, and a semiconductor laser evaluation apparatus for optical output characteristics of a laser diode is provided.

  8A and 8B are external perspective views of the laser coupler. In the figure, reference numeral 10 denotes a laser coupler, and the laser coupler 10 is mounted so that an optical integrated element 100 is mounted on a ceramic die plate 15 and covers the optical integrated element 100 as shown in FIG. A protective cover 16 having a window 16a and openings 16b and 16c is provided. Here, an example of the size of the laser coupler is about 8 mm wide, 4 mm deep, and 3 mm high.

  In the optical integrated device 100, a semiconductor laser 104 is mounted on a photo detector IC 101 having two photodiodes PD1 and PD2, and the output is monitored to change the drive current so as to be constant ( An FPDIC (Front Monitor Photo Detector IC) 103 for performing APC (Automatic Power Control) and an optical microprism 102 are disposed adjacent to each other.

As shown in FIG. 8B, the die plate 15 has a die pad 15a made of a metal film for releasing generated heat on the surface opposite to the mounting surface of the optical integrated device 100, and the optical integrated device 100 on the three sides around the die pad 15a. Lands 15b, 15b,... Here, the pitch interval between the lands 15b, 15b,... Formed in the laser coupler 10 is approximately 0.5 mm.
The cover 16 is provided with a laser beam exit window 16a and two openings 16b and 16c for heat dissipation.
Then, the laser coupler 10 configured as described above irradiates laser light from the semiconductor laser 104 from the optical integrated device 100 and reflects the light reflected by the optical disk D as shown in FIG. Then, light is received by the photodiodes PD1 and PD2 of the photo-detector IC 101, and an information signal recorded on the optical disc D is converted into an electric signal and an electric signal for servo is calculated and obtained.

Next, a semiconductor laser evaluation apparatus for the laser output of the laser coupler 10 will be described.
FIG. 1 is a block diagram for explaining a system for measuring the forward current-optical output characteristics (hereinafter referred to as “IL characteristics”) of the laser output of the laser coupler 10. As shown in FIG. 1, this measurement system is generally composed of two parts: a laser beam emitting part 1 and a light detecting part 2 that receives the emitted laser light.
The emission unit 1 includes a laser coupler 10, a laser driver circuit 50 for driving the laser coupler 10, a temperature control unit 30 that adjusts the temperature of the laser coupler 10 to stabilize at a predetermined value, It consists of power supply units that do not.
On the other hand, as shown in FIG. 3, the light detection unit 2 is a so-called optical power meter provided with a photodetector 2a having a circular light receiving unit on an upper part of a strip-shaped plate and a light detection measurement circuit 2b (not shown). .
The circular light receiving portion of the photodetector 2a is provided on the output window of the laser coupler 10 so that the light spreading from the optical axis can be received on the optical axis of the laser light emitted from the emitting portion 1 without leakage. It is arranged near 16a so as to obtain an IL characteristic at a temperature during a predetermined operation.

FIG. 2 is a block diagram showing a configuration of the emitting unit 1 shown in FIG.
The temperature control unit 30 includes a temperature sensor 31 such as a thermistor or a thermocouple, a temperature control circuit 32 that outputs a temperature adjustment signal from temperature information from the temperature sensor 31 and a preset temperature, and a predetermined temperature based on the temperature adjustment signal. The heat generation / absorption element 33 is a Peltier element for generating / absorbing heat, and the heat plate 34 is firmly fixed to the heat generation / absorption element 33. The heat plate 34 and the laser coupler 10 are thermally connected by a heat transfer member 18 indicated by a broken line.
On the other hand, the laser coupler 10 is electrically connected to a laser driving board (hereinafter referred to as “LDD board”) 52 which is a component driving board on which a laser driver IC for driving the laser coupler 10 is mounted via the socket 20. Further, the LDD substrate 52 is connected to the control substrate 51, and the laser driver IC is serially controlled.

Next, a specific structure of the emitting unit 1 will be described.
4A and 4B are a side sectional view and an external perspective view, respectively, for explaining the mounting structure of the laser coupler 10 of the semiconductor laser evaluation apparatus of this example. As shown in FIG. 4B, the heat transfer member 18 and the bracket 26 are fixed to the heat plate 34 that is tightly fixed to the temperature control unit 30 indicated by the broken line, and the socket in which the laser coupler 10 is mounted to the bracket 26. 20 is provided.

The heat plate 34 is a plate made of a metal having good thermal conductivity, and the heat generating / heat absorbing element 33 is fixed to the lower surface. At this time, for example, both surfaces are meshed so as to be in contact with each other and have a large contact area so that the heat transfer between the heat generating / absorbing element 33 and the heat plate 34 can be performed quickly. It is good to make it.
The bracket 26 is made of metal or the like from the viewpoint of strength, and is erected on the hot plate 34 to fix the socket 20. As shown in FIGS. 4A and 4B, the bracket 26 is 2 upward from the attachment portion 26 a with the hot plate 34. Two arms 26b and 26b are projected, and a positioning hole and a fixing screw hole (not shown) for the socket 20 are provided in the arms 26b and 26b. If the bracket 26 made of metal is directly fixed to the hot plate 34, the bracket 26 will carry heat transfer as a part of the hot plate 34, which acts as a heat sink and affects the temperature distribution of the hot plate 34. Therefore, the bracket 26 is preferably fixed to the heat plate 34 through a heat insulating sheet or the like.

As shown in FIGS. 5A and 5B, the socket 20 is a molded product made of a plastic mold having a size of, for example, a width of 25 mm, a depth of 22 mm, and a height of about 15 mm and having four legs. Then, as shown in FIG. 5A, a concave portion 20a having a convex bottom surface is provided on the surface 20-1 to hold the laser coupler 10. Contact pins 20b, 20b,... Serving as contact terminals are provided at positions corresponding to the lands 15b, 15b,... (FIG. 8B) of the laser coupler 10 on the bottom surface of the recess 20a, and penetrated to positions corresponding to the die pad 15a. A hole 20f is provided. Here, a total of 20 contact pins 20b, 20b,... Are provided with a pitch of about 0.5 mm between the lands 15b, 15b,... Of the laser coupler 10 shown in FIG.
Then, the contact pins 20b, 20b,... Provided in the recess 20a on the front surface 20-1 side of the socket 20 are extended to the back surface 20-2 side and project at a predetermined interval and length as shown in FIG. 5B. The lead pins 20c, 20c,.

5A of the socket 20 is provided with a pressing member (not shown) such as a spring for detachably holding the laser coupler 10 in the recess 20a. On the other hand, projections 20d and 20d for positioning with the bracket 26 and screw insertion holes 20e and 20e for fixing are provided on the front end surface of the leg portion of the socket 20 shown in FIG. 5B.
The lead pins 20c, 20c,... Provided on the back surface 20-2 side of the socket 20 are contact pins 20b on the surface 20-1 side that are formed in accordance with the pitch intervals of the lands 15b, 15b,. Since it is difficult to connect to the LDD substrate 52 with the pitch of 20b,..., The distance between the pins is extended to form, for example, approximately 2 mm.

The heat transfer member 18 is erected on the heat plate 34, and as shown in FIG. 6, one stand 18b protrudes upward from a mounting portion 18a with the heat plate 34, and the heat plate is formed from the upper part of the stand 18b. A shaft 18c extending substantially in parallel with 34 is provided. Here, as shown in FIG. 4A, the shaft 18 c is manufactured to have a height and thickness that can be inserted into the through hole 20 f of the socket 20 in a state of being fixed to the bracket 26.
And in the axial direction of this shaft 18c, in order to insert and fix a temperature sensor, as shown to FIG. 4A and FIG. 5, the through-hole 18d is provided. The attachment portion 18a is provided with four long holes 18f for inserting fixing screws.
The temperature sensor 31 is selected from among various types such as a thermocouple and a thermistor resistor by the temperature control unit 30 to be used, and the tip of the shaft 18c of the heat transfer member 18 close to the die pad 15a (FIG. 8) of the laser coupler 10. The temperature near the surface 18e is measured. The detected temperature signal is input to the temperature control unit 30.

As shown in FIG. 4A, the semiconductor laser evaluation apparatus for the light output characteristics of the laser diode configured as described above first places and fixes the bracket 26 on the hot plate 34 provided in the temperature control unit 30. . Then, the heat transfer member 18 is placed on the heat plate 34, and screws are lightly screwed into the four long holes 18f so that the heat transfer member 18 can move in the axial direction of the shaft 18c.
On the other hand, a connector (not shown) that is electrically connected to the LDD substrate 52 (FIG. 2) is connected to the socket 20 on the lead pins 20c, 20c,.
Then, the socket 20 is positioned and fixed using a positioning hole and a fixing screw hole (not shown) of the bracket 26 with the shaft 18c of the heat transfer member 18 inserted through the through hole 20f (FIG. 4A).

Then, the position of the heat transfer member 18 is finely adjusted on the heat plate 34 so that the front end surface 18e of the shaft 18c of the heat transfer member 18 shown in FIG. 4 is substantially flush with the bottom surface of the recess 20a of the socket 20. (Fig. 4A).
Then, the temperature sensor 31 connected to the temperature control unit 30 is inserted into the through hole 18d of the heat transfer member 18 from the left side shown in FIG. 4A, and is fixed to a position close to the tip surface 18e and not protruding.
Thus, the emission unit 1 of the semiconductor laser evaluation apparatus shown in FIG. 1 is assembled.
Finally, the light receiving portion of the photodetector 2a of the light detecting portion 2 shown in FIG. 1 is provided at a position where all the light emitted from the laser coupler 10 can be received (see FIG. 3).

In the operation of the semiconductor laser evaluation apparatus configured as described above, first, the environmental temperature for operating the laser coupler 10 is set in advance and the temperature control unit is operated. Then, a predetermined current is input from the control board 51 to the laser coupler 10 via the LDD board 52 and the socket 20, and the output of the laser beam with respect to this input current is measured by the light detection unit 2 (power meter). Thereafter, similarly, by changing the input forward current at a predetermined current interval and measuring the output of the laser beam with respect to each input forward current by the light detection unit 2, an IL characteristic curve at a temperature during a predetermined operation is obtained. be able to.
FIG. 7 is an example of the IL characteristic at a predetermined temperature obtained in this manner. The horizontal axis represents the input forward current (mA), and the vertical axis represents the laser light output (mW). It can be seen that the output increases almost linearly with respect to the input forward current after the laser beam begins to be emitted. Although the scale is arbitrarily shown in FIG. 7, a threshold current (I _th ) that is a current at which laser light starts to be emitted by actual measurement of a predetermined product and an operating current (I _op ) for obtaining a predetermined laser output are shown. Can be read.

During the characteristic evaluation test, the semiconductor laser 104 shown in FIG. 9 generates heat due to the operation of the laser coupler 10. This heat is generated by the optical integrated device 100, the die pad 15 a of the laser coupler 10, the tip surface 18 e of the heat transfer member 18, The shaft 18c, the stand 18b, the mounting portion 18a, and the heat plate 34 are transmitted in this order to dissipate heat, so that the temperature of the laser coupler 10 approaches the temperature of the heat plate 34.
On the other hand, the temperature of the laser coupler 10 is monitored by a temperature sensor 31 provided at the tip of the shaft 18c near the die pad 15a, and this temperature information is input to the temperature control circuit 32 (FIGS. 2 and 4A).

When the temperature of the laser coupler 10 becomes higher than the preset temperature, the heat generating / heat absorbing element 33 performs a heat absorbing operation, that is, an electronic cooling operation. Further, when the temperature of the laser coupler 10 becomes lower than the set temperature due to the heat absorption operation, the heat generation / heat absorption element 33 performs a heat generation operation.
That is, temperature adjustment is performed centering on a preset temperature condition, and the temperature of the laser coupler 10 is monitored by the temperature sensor 31 disposed at a position adjacent to the die pad 15a, so that responsiveness in temperature control is achieved. Good and accurate.
In addition, since the heat generating / heat absorbing element 33 such as a Peltier element that can absorb heat or generate heat by changing the polarity of the voltage to be applied is used, it can be configured simply and compactly.

  As described above, in the semiconductor laser evaluation apparatus of this example, even if the heat generating portion (optical integrated element) is mounted on a die plate made of a ceramic substrate having relatively small heat conductivity like a laser coupler, the heat dissipation on the ceramic substrate is performed. A conventional metal can package that can quickly dissipate heat from caps, stems, and lead pins made of metal by contacting the heat transfer member to the pad and thermally connecting to a temperature-controlled hot plate. As in the semiconductor laser, the characteristics using the operating temperature as a parameter can be efficiently evaluated.

  In the above example, the setting of the operating temperature of the laser coupler, the setting of the input current value to the laser output, and the measurement of the laser output have been described as separate procedures for convenience of explanation. Can be measured at intervals of 10 ° C. from −20 ° C. to 90 ° C. and the input current is increased from 0 mA to 1 mA in increments of 0.05 mA, and the laser output at that time can be automatically measured. It can be implemented by a sequencer or a personal computer by providing an appropriate input / output interface for each of the light detection units 2.

In the above example, the measurement of the IL characteristic is described as an example of the characteristic of the laser beam. However, the monitor output current (I _m ) -the optical output characteristic or the forward current is assumed to use the optical power meter for the light detection unit 2. It can also be used to evaluate (I _f ) -forward voltage (V _f ) characteristics.
In addition, the semiconductor laser evaluation apparatus has been described with the measurement system having the emission unit 1 and the light detection unit 2. However, instead of evaluating the laser characteristics, the semiconductor device has a die pad for heat dissipation on one side, and the electrical characteristics are It is possible to evaluate the characteristics of electronic components having remarkable temperature dependency, such as optical elements and ICs, with the same configuration. In this case, instead of the light detection unit, a characteristic detection unit required according to characteristics collected by the electronic component is provided, and a component drive substrate for the electronic component is provided instead of the LDD substrate (FIG. 2).

Further, the electrical connection between the socket 20 and the laser coupler 10 is performed by connection lands 15b, 15b,... On the lower surface of the laser coupler 10 and contact pins 20b, 20b,. However, the present invention is not limited to this, and when the connection land is provided on the upper surface side of the die plate, a contact pin may be provided on the pressing member that detachably holds the laser coupler 10.
Furthermore, although the laser coupler 10 in this example has been described as an example having the die pad 15a for heat dissipation on the lower surface of the laser coupler 10, the present invention is not limited to this, and a metal pad for heat dissipation is provided on one surface such as the side surface of the die plate 15. In this case, a socket having a shape corresponding to the form of the laser coupler 10 at this time may be used, and these may be thermally connected via a heat transfer member that is in contact with the metal pad and the heat plate. .

  According to the semiconductor laser evaluation apparatus of this example, temperature adjustment is performed centering on a preset temperature condition, and the temperature of the laser coupler is monitored by a temperature sensor arranged at a position adjacent to the die pad of the laser coupler. Therefore, the responsiveness in temperature control is good and can be performed with high accuracy. In addition, since a heat-generating / heat-absorbing element such as a Peltier element that can absorb heat or generate heat by changing the polarity of the applied voltage is used, it can be configured simply and compactly. In addition, it is possible to efficiently and accurately evaluate the electrical characteristics using the temperature during operation of the laser coupler as a parameter.

It is a block diagram which shows the measuring system of the semiconductor laser evaluation apparatus of the example of one embodiment of this invention. FIG. 2 is a detailed view of an emission unit in the block diagram of the example in FIG. 1. FIG. 2 is a detailed diagram of a light detection unit in the block diagram of the example in FIG. 1. 1A and 1B are side sectional views and B, respectively, illustrating a structure of a laser coupler mounting portion in a semiconductor laser evaluation apparatus according to an example of an embodiment of the present invention. It is an external appearance perspective view of the laser coupler attachment socket in the semiconductor laser evaluation apparatus of the example of one embodiment of the present invention, and A is the figure seen from the surface side and B from the back side. It is an external appearance perspective view of the heat transfer means in the semiconductor laser evaluation apparatus of the example of one embodiment of the present invention. It is an example of the operating characteristic (IL characteristic) figure of the laser coupler obtained with the semiconductor laser evaluation apparatus of FIG. 1 example. 1 is an external perspective view of a laser coupler that is an electronic component to be measured in a semiconductor laser evaluation apparatus according to an example of an embodiment of the present invention, where A is an optical integrated device mounting side and B is a die pad side. . FIG. 9 is an external perspective view of the optical integrated device of the laser coupler of FIG. 8 example. FIG. 9 is a side sectional view of an optical integrated device of the laser coupler of FIG. 8 example. It is a figure where it uses for description of operation | movement of a laser coupler. In the conventional metal can package type semiconductor laser, A is an external perspective view, and B is an explanatory view of a mounting structure. FIG. 13 is an example of an operating characteristic diagram without temperature control of the semiconductor laser of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Output part, 10 ... Laser coupler, 18 ... Heat transfer member, 20 ... Socket, 30 ... Temperature control unit, 31 ... Temperature sensor, 32 ... Temperature control circuit, 33 ... Exothermic / heat-absorbing element, 34 ... Heat plate, 51 ... Control board, 52 ... LDD board (Laser diode driver board)

Claims (4)

In a semiconductor laser evaluation apparatus for evaluating the characteristics of a semiconductor laser having a characteristic detection unit and a component driving unit, and having a heat dissipation unit on one surface of a package substrate,
The component drive unit is
A component drive board on which an electronic circuit for driving the semiconductor laser is mounted;
A control board for controlling the component drive board;
An electrical contact terminal with the connection terminal of the semiconductor laser is provided, the contact terminal extends so as to be electrically connectable to the connection terminal of the component drive board, and the semiconductor laser is detachable A socket having a through hole at a position corresponding to the heat radiating portion;
A heat plate and a temperature control unit for controlling the temperature of the heat plate;
A heat transfer member provided on the hot plate and having a protrusion inserted into the through hole of the socket;
A semiconductor laser evaluation apparatus comprising: The semiconductor laser evaluation apparatus according to claim 1,
A semiconductor laser evaluation apparatus, wherein a temperature sensor is provided in the vicinity of a contact portion of the heat transfer member with the semiconductor laser, and constant temperature control is performed so that the semiconductor laser during operation has a predetermined temperature. The semiconductor laser evaluation apparatus according to claim 2,
While controlling the temperature during operation of the semiconductor laser at a constant temperature,
Characteristics of the semiconductor laser using the temperature at the time of operation as a parameter so as to obtain an output value by sequentially changing the drive input value input from the component drive board to the semiconductor laser to a preset value. The semiconductor laser evaluation apparatus characterized by obtaining. In the semiconductor laser evaluation apparatus according to claim 3,
The semiconductor laser is a laser coupler equipped with an optical integrated device for reproducing an information signal recorded on an optical disk recording medium mounted with a laser diode, and the laser diode when the characteristic is a forward current as an input value The light output characteristics of
In the characteristic detector, using a photodetector that detects the output of the laser diode,
A laser drive board having a laser driver IC for driving the laser diode mounted on the component drive board and having an electrical connection terminal in the component drive section, and a laser control board for controlling the laser drive board on the control board Using the heat plate, the temperature control unit using a Peltier element, and the heat transfer member,
A semiconductor laser evaluation apparatus characterized in that the light output characteristic is obtained by using the temperature of the laser coupler during operation as a parameter.

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