Double-ended excitation laser amplifier and method of manufacturing electronic device

Abstract

To provide a double-ended excitation laser amplifier that prevents an end cap from being heated to be damaged by the energy of light which has not been absorbed by a laser amplifying medium.SOLUTION: A double-ended excitation laser amplifier comprises: a laser amplification medium configured to amplify pulsed seed light; an excitation light source configured to output excitation light; a first λ / 4 wavelength plate and a first λ / 2 wavelength plate through which the excitation light is transmitted; a first polarizing beam splitter configured to separate the excitation light transmitted through the first λ / 4 wavelength plate and the first λ / 2 wavelength plate into first light in a first polarization direction and second light in a second polarization direction; a first incident optical system configured to cause the first light to be incident on a first end of the laser amplification medium; and a second incident optical system configured to cause the second light to be incident on a second end of the laser amplification medium.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a double-ended pumped laser amplifier and a method for manufacturing an electronic device. [Background technology]

[0002] In recent years, semiconductor exposure devices have been required to improve their resolution in response to the miniaturization and high integration of semiconductor integrated circuits. To this end, the wavelength of light emitted from exposure light sources has been shortened. For example, KrF excimer laser devices, which output laser light with a wavelength of approximately 248 nm, and ArF excimer laser devices, which output laser light with a wavelength of approximately 193 nm, are used as gas laser devices for exposure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 5,412,683 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-051897 [Patent Document 3] US Patent Application Publication No. 2009 / 245304 [Non-patent literature]

[0004] [Non-Patent Document 1] Luo Guangxin, Liu Yinfei, Song Jiajun, et al. A double-ended pump thin-rod Yb: YAG regenerative amplifier with high average power and excellent beam quality[DS / OL]. V1. Science Data Bank, 2023[2024-01-21]. https: / / cstr.cn / 31253.11.sciencedb.07851. CSTR:31253.11.sciencedb.07851.Summary

[0005] A double-ended pumped laser amplifier according to one aspect of the present disclosure includes a laser amplification medium that amplifies pulsed seed light, a pumping light source that outputs pumping light, a first λ / 4 wave plate and a first λ / 2 wave plate through which the pumping light passes, a first polarizing beam splitter that separates the pumping light that has passed through the first λ / 4 wave plate and the first λ / 2 wave plate into a first light having a first polarization direction and a second light having a second polarization direction, a first incident optical system that makes the first light incident on a first end of the laser amplification medium, and a second incident optical system that makes the second light incident on a second end of the laser amplification medium.

[0006] A double-ended pumped laser amplifier according to one aspect of the present disclosure includes a laser amplification medium that amplifies pulsed seed light, a pumping light source that outputs linearly polarized pumping light, a first λ / 2 wave plate through which the pumping light passes, a first polarizing beam splitter that separates the pumping light that has passed through the first λ / 2 wave plate into a first light having a first polarization direction and a second light having a second polarization direction, a first incident optical system that makes the first light incident on a first end of the laser amplification medium, and a second incident optical system that makes the second light incident on a second end of the laser amplification medium.

[0007] A method for manufacturing an electronic device according to one aspect of the present disclosure includes generating laser light using a laser apparatus including a seed laser that outputs pulsed seed light, a laser amplification medium that amplifies the seed light, a pumping light source that outputs pumping light, a first λ / 4 wave plate and a first λ / 2 wave plate through which the pumping light passes, a first polarizing beam splitter that separates the pumping light that has passed through the first λ / 4 wave plate and the first λ / 2 wave plate into a first light having a first polarization direction and a second light having a second polarization direction, a first incident optical system that makes the first light incident on a first end of the laser amplification medium, and a second incident optical system that makes the second light incident on a second end of the laser amplification medium, laser processing an interposer substrate with the laser light to fabricate an interposer, bonding the interposer and an integrated circuit chip to electrically connect them to each other, and bonding the interposer and a circuit board to electrically connect them to each other.

[0008] A method for manufacturing an electronic device according to one aspect of the present disclosure includes generating laser light using a laser apparatus including: a seed laser that outputs pulsed seed light; a laser amplification medium that amplifies the seed light; an excitation light source that outputs linearly polarized excitation light; a first λ / 2 wave plate through which the excitation light passes; a first polarizing beam splitter that separates the excitation light that has passed through the first λ / 2 wave plate into a first light having a first polarization direction and a second light having a second polarization direction; a first incident optical system that makes the first light incident on a first end of the laser amplification medium; and a second incident optical system that makes the second light incident on a second end of the laser amplification medium; laser processing an interposer substrate with the laser light to fabricate an interposer; bonding the interposer and an integrated circuit chip to electrically connect them to each other; and bonding the interposer and a circuit board to electrically connect them to each other. [Brief explanation of the drawings]

[0009] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 shows the configuration of a laser processing system in a comparative example. [Figure 2] FIG. 2 shows the configuration of the laser amplifier according to the first embodiment. [Figure 3] FIG. 3 shows the configuration of the first λ / 4 wave plate. [Figure 4] FIG. 4 shows the configuration of the first λ / 2 wave plate. [Figure 5] FIG. 5 shows the configuration of a laser amplifier according to a first modification of the first embodiment. [Figure 6] FIG. 6 shows the configuration of a laser amplifier according to a second modification of the first embodiment. [Figure 7] FIG. 7 shows the configuration of a laser amplifier according to the second embodiment. [Figure 8] FIG. 8 is a perspective view of the third polarizing beam splitter, showing in more detail the area inside the box VIII shown in FIG. [Figure 9] FIG. 9 shows the configuration of a laser amplifier according to the third embodiment. [Figure 10]FIG. 10 shows a schematic configuration of the electronic device. [Figure 11] FIG. 11 is a flowchart showing a method for manufacturing an electronic device. Embodiment

[0010] <Contents> 1. Comparative Example 1.1 Configuration 1.2 Operation 1.3 Issues with the comparative example 2. Adjusting the split ratio by adjusting the polarization state of laser amplifier 1a 2.1 Configuration 2.2 Operation 2.3 First variant 2.3.1 Configuration 2.3.2 Operation 2.4 Second Variant 2.5 Effect 3. Laser amplifier 1d capable of adjusting the light intensities of the first and second lights 3.1 Configuration 3.2 Operation 3.2.1 Adjusting the light intensity of the first light 3.2.2 Adjusting the intensity of the second light 3.3 Effect 4. Laser amplifier 1e including pump laser PL3 that outputs linearly polarized light 4.1 Configuration 4.2 Operation 4.3 Effect 5.Other 5.1 Electronic Devices Containing Interposer IP 5.2 Supplementary Information

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The embodiments described below show some examples of the present disclosure and do not limit the content of the present disclosure. Furthermore, not all of the configurations and operations described in each embodiment are necessarily essential as the configurations and operations of the present disclosure. Note that the same components are given the same reference symbols, and redundant explanations will be omitted.

[0012] 1. Comparative Example 1.1 Configuration 1 shows the configuration of a laser processing system in a comparative example. The comparative example of the present disclosure is a configuration that the applicant recognizes as being known only by the applicant, and is not a publicly known example that the applicant acknowledges. The laser processing system includes a seed laser SL, a laser amplifier 1, and a laser irradiation device 2.

[0013] The seed laser SL is a laser oscillator that outputs pulsed seed light SB1. The wavelength of the seed light SB1 is, for example, approximately 1030 nm. The laser amplifier 1 amplifies the seed light SB1 and outputs pulsed laser light LB. The laser light LB may be converted to an oscillation wavelength of a KrF excimer laser device or an ArF excimer laser device (not shown) and further amplified by such an excimer laser device. The laser irradiation device 2 includes an irradiation optical system (not shown) for irradiating a workpiece (not shown) with the laser light LB. The workpiece is, for example, an interposer substrate for manufacturing an interposer IP that connects an integrated circuit chip IC and a circuit board CS, which will be described later with reference to FIG. 10.

[0014] The laser amplifier 1 includes pump lasers PL1 and PL2, end caps EC1 and EC2, collimating lenses CL1 and CL2, focusing lenses FL1 and FL2, dichroic mirrors DM1 and DM2, and a laser amplification medium AMP.

[0015] The laser amplification medium AMP is, for example, a crystal of Yb:YAG (Ytterbium-doped Yttrium Aluminum Garnet).

[0016] The pump lasers PL1 and PL2 are pump light sources that output pump light, and are composed of, for example, semiconductor lasers or solid-state lasers. The wavelength of the pump light is set according to the absorption wavelength of the laser amplification medium AMP. When the laser amplification medium AMP is a Yb:YAG crystal, the wavelength of the pump light is set to either 940 nm or 969 nm.

[0017] End caps EC1 and EC2 are placed at the output ends of the optical fibers connected to pump lasers PL1 and PL2, respectively.

[0018] The collimating lenses CL1 and CL2 are disposed in the optical paths of the excitation light beams B1 and B5 emitted from the end caps EC1 and EC2, respectively. The focal lengths of the collimating lenses CL1 and CL2 are, for example, 12 mm.

[0019] The focus lenses FL1 and FL2 are disposed in the optical paths of the excitation light beams B2 and B6 emitted from the collimator lenses CL1 and CL2, respectively. The focal lengths of the focus lenses FL1 and FL2 are, for example, 250 mm. The focus lenses FL1 and FL2 correspond to the first and second incident optical systems, respectively, in this disclosure.

[0020] The dichroic mirrors DM1 and DM2 are arranged to align the optical path axis of the seed light SB1 output from the seed laser SL with the optical path axis of the excitation light B output from the focus lenses FL1 and FL2, respectively. 17 and B 36 The dichroic mirrors DM1 and DM2 reflect the wavelength components contained in the seed light SB1 and the excitation light B 17 and B 36 The optical filter is configured to transmit wavelength components included in the wavelength component.

[0021] 1.2 Operation The pumping light beams output from the pump lasers PL1 and PL2 are emitted as diverging pumping light beams B1 and B5 from the end caps EC1 and EC2, respectively. The pumping light beams B1 and B5 are converted into parallel pumping light beams B2 and B6 by the collimating lenses CL1 and CL2, respectively. The pumping light beams B2 and B6 are converted into convergent pumping light beams B6 by the focusing lenses FL1 and FL2, respectively. 17 and B 36 In each figure, only the optical axis of the light beam is shown.

[0022] Excitation light B emitted from focus lens FL1 17is transmitted through the dichroic mirror DM1, and excitation light B 18 The pumping light B emitted from the focus lens FL2 is focused at the first end E1 of the laser amplification medium AMP. 36 is transmitted through the dichroic mirror DM2, and excitation light B 37 The pumping light B incident on the laser amplifying medium AMP is focused at the second end E2 of the laser amplifying medium AMP. 18 and B 37 The term "coaxial" does not necessarily mean that the optical path axes of the two light beams are perfectly aligned, but includes an error within a practical range, for example, an error of 1° or less.

[0023] The seed light SB1 emitted from the seed laser SL is reflected by the dichroic mirror DM1 and enters the first end E1 as seed light SB3.

[0024] The laser amplification medium AMP receives the pumping light B 18 and B 37 The seed light SB3 is excited by the energy of the laser beam LB4 and amplified as a seed light SB3. The amplified seed light SB3 is emitted from the second end E2 as a laser light LB4.

[0025] The laser light LB4 emitted from the second end E2 of the laser amplification medium AMP is reflected by the dichroic mirror DM2 and output as the laser light LB.

[0026] Excitation light B 18 and B 37 is, for example, a continuous wave laser beam. Alternatively, the excitation light B 18 and B 37 may be a pulsed laser beam, in which case the pulse of seed light SB3 and the pumping light B 18 and B 37 The pulses are synchronized so that they overlap in the laser amplifying medium AMP.

[0027] Excitation light B 18 and B 37 It is desirable to adjust the excitation light B so that they have the same light intensity. 18 and B37 In order to adjust the light amount, for example, the voltages applied to the pump lasers PL1 and PL2 are controlled.

[0028] 1.3 Issues with the comparative example Excitation light B 18 and B 37 The pump light B is not completely absorbed in the laser amplifying medium AMP. 18 The light that is not absorbed in the laser amplification medium AMP exits from the second end E2, passes through the dichroic mirror DM2, the focus lens FL2, and the collimator lens CL2, and enters the end cap EC2, which may damage the pump laser PL2. 37 The light that is not absorbed in the laser amplifying medium AMP may also damage the pump laser PL1, or the energy of this light may heat and damage the end caps EC1 and EC2.

[0029] In the comparative example, the pumping light B incident on the laser amplification medium AMP 18 and B 37 It may not be easy to set the light intensity.

[0030] The embodiment described below prevents the pump lasers PL1 and PL2 from being damaged by the pumping light that is not absorbed in the laser amplification medium AMP, and further prevents the pumping light B incident on the laser amplification medium AMP from being damaged. 18 and B 37 This relates to a double-ended pumped laser amplifier that allows the amount of light to be set.

[0031] 2. Adjusting the split ratio by adjusting the polarization state of laser amplifier 1a 2.1 Configuration 2 shows the configuration of a laser amplifier 1a according to the first embodiment. The laser amplifier 1a is an example of a double-ended pumped laser amplifier according to the present disclosure. The laser amplifier 1a includes a pump laser PL, an end cap EC, a collimating lens CL, a first λ / 4 wave plate λ / 4P1, a first λ / 2 wave plate λ / 2P1, a first polarizing beam splitter PBS1, and high-reflection mirrors M1 to M5.

[0032] The pump laser PL, end cap EC, and collimating lens CL are the same as the pump laser PL1, end cap EC1, and collimating lens CL1 in the comparative example. The laser amplifier 1a does not necessarily include the pump laser PL2, end cap EC2, and collimating lens CL2. The laser amplifier 1a further includes focus lenses FL1 and FL2, dichroic mirrors DM1 and DM2, and a laser amplification medium AMP, which are the same as those described in the comparative example.

[0033] The first λ / 4 wave plate λ / 4P1 is disposed in the optical path of the excitation light B2 emerging from the collimator lens CL.

[0034] FIG. 3 shows the configuration of the first λ / 4 wave plate λ / 4P1. The first λ / 4 wave plate λ / 4P1 imparts a phase difference of ¼ of the wavelength λ of the excitation light B2 between the polarization component parallel to the optical axis A1 and the polarization component perpendicular to the optical axis A1 of the incident excitation light B2. This allows the first λ / 4 wave plate λ / 4P1 to change the polarization state of the excitation light B2 and output it as excitation light B3. The polarization state of the excitation light B3 is determined by the polarization state of the excitation light B2 and the direction of the optical axis A1. For example, when the excitation light B2 incident on the first λ / 4 wave plate λ / 4P1 contains a circularly or elliptically polarized component, the emitted excitation light B3 may contain a linearly polarized component. Rotating the first λ / 4 wave plate λ / 4P1 as indicated by the arrow θ1 using the rotation mechanism AC1 changes the direction of the optical axis A1, adjusting the polarization state of the excitation light B3. The rotation mechanism AC1 corresponds to the second rotation mechanism in this disclosure.

[0035] 2, the first λ / 2 wave plate λ / 2P1 is disposed in the optical path of the excitation light B3 emitted from the first λ / 4 wave plate λ / 4P1. Alternatively, the positional relationship between the first λ / 4 wave plate λ / 4P1 and the first λ / 2 wave plate λ / 2P1 may be reversed.

[0036] FIG. 4 shows the configuration of the first λ / 2 wave plate λ / 2P1. The first λ / 2 wave plate λ / 2P1 imparts a phase difference of half the wavelength λ of the excitation light B3 between the polarization component parallel to the optical axis A2 and the polarization component perpendicular to the optical axis A2 of the incident excitation light B3. This allows the first λ / 2 wave plate λ / 2P1 to change the polarization state of the excitation light B3 and output it as excitation light B4. The polarization state of the excitation light B4 is determined by the polarization state of the excitation light B3 and the direction of the optical axis A2. For example, when the direction of the optical axis A2 is tilted by an angle φ with respect to the polarization direction of the linearly polarized excitation light B3 incident on the first λ / 2 wave plate λ / 2P1, linearly polarized excitation light B4 is output, whose polarization direction is tilted by an angle 2φ with respect to the polarization direction of the excitation light B3. When the first λ / 2 wave plate λ / 2P1 is rotated by the rotation mechanism AC2 as shown by the arrow θ2, the direction of the optical axis A2 changes, and the polarization state of the excitation light B4 is adjusted. The rotation mechanism AC2 corresponds to the first rotation mechanism in this disclosure.

[0037] Referring again to FIG. 2, the first polarizing beam splitter PBS1 includes an optical thin film that transmits the P-polarized component and reflects the S-polarized component. For example, if the polarization direction of the excitation light B4 is tilted at 45° with respect to the plane of incidence of the excitation light B4 on this optical thin film, the light amounts of the P-polarized component and the S-polarized component of the excitation light B4 will be equal. In this case, the excitation light B4 reflected by the first polarizing beam splitter PBS1 10 and the excitation light B transmitted through the first polarizing beam splitter PBS1. 30 and are almost the same amount of light.

[0038] 2.2 Operation The pump light output from the pump laser PL is emitted from the end cap EC as pump light B1 and passes through the collimator lens CL as pump light B2. The pump light B2 passes through the first λ / 4 wave plate λ / 4P1 and the first λ / 2 wave plate λ / 2P1, and is emitted as pump light B4 with its polarization state adjusted. The first polarizing beam splitter PBS1 splits the pump light B4 into the pump light B 10 and B 30 Excitation light B 10 The polarization direction of the excitation light B is the first polarization direction perpendicular to the paper surface of Figure 2. 30 The polarization direction of is a second polarization direction parallel to the paper surface of FIG.

[0039] Excitation light B 10 are pumped by the high-reflection mirrors M1, M2, and M3, respectively. 11 , B 15 , and B 16 Excitation light B is reflected as 16 are the focus lens FL1 and the dichroic mirror DM1, respectively, and the excitation light B 17 and B 18 The light is transmitted as a beam and enters the first end E1 of the laser amplification medium AMP.

[0040] Excitation light B 30 are reflected by high-reflection mirrors M4 and M5, respectively. 34 and B 35 Excitation light B is reflected as 35 are the focus lens FL2 and the dichroic mirror DM2, respectively, and the excitation light B 36 and B 37 The light is transmitted as a beam and enters the second end E2 of the laser amplification medium AMP.

[0041] Excitation light B 10 from excitation light B 18 and excitation light B 30 from excitation light B 37The light from the first polarizing beam splitter PBS1 to the laser amplification medium AMP corresponds to the first and second light, respectively, in this disclosure. It is desirable that the light intensities of the first and second light are the same. Here, "same" does not necessarily mean that they are completely the same, but includes an error of 5% or less. It is also desirable that the optical path lengths of the first and second light from the first polarizing beam splitter PBS1 to the laser amplification medium AMP are the same.

[0042] Excitation light B 18 The light that is not absorbed in the laser amplification medium AMP is emitted from the second end E2 as pumping light B 19 and passes through the dichroic mirror DM2, the focus lens FL2, and the high-reflection mirrors M5 and M4 to form excitation light B. 20 , B 21 , and B 22 and the excitation light B 23 The excitation light B may enter the first polarizing beam splitter PBS1 as 23 has a polarization direction perpendicular to the paper surface of FIG. 2 and is S-polarized with respect to the optical thin film of the first polarizing beam splitter PBS1, so the excitation light B 50 This can prevent damage to the pump laser PL and the end cap EC. 50 A beam damper D is placed in the optical path.

[0043] Excitation light B 37 The light that is not absorbed in the laser amplification medium AMP is emitted from the first end E1 as pumping light B 38 The light is then emitted as excitation light B via dichroic mirror DM1, focus lens FL1, and high-reflection mirrors M3, M2, and M1. 39 , B 40 , B 41 , and B 42 and the excitation light B 44 The excitation light B may enter the first polarizing beam splitter PBS1 as 44 has a polarization direction parallel to the paper surface of FIG. 2 and is P-polarized with respect to the optical thin film of the first polarizing beam splitter PBS1, so the excitation light B 50This can prevent damage to the pump laser PL and the endcap EC.

[0044] The seed beams SB1 and SB3 and the laser beams LB4 and LB are the same as those in the comparative example.

[0045] In other respects, the first embodiment is similar to the comparative example.

[0046] 2.3 First variant 2.3.1 Configuration 5 shows the configuration of a laser amplifier 1b according to a first modification of the first embodiment. The laser amplifier 1b is an example of a double-ended pumped laser amplifier according to the present disclosure. The laser amplifier 1b differs from the laser amplifier 1a in that it includes a second polarizing beam splitter PBS2, a second λ / 4 wave plate λ / 4P2, and a high-reflection mirror M6 as a configuration for amplifying seed light SB1 twice and outputting laser light LB. The beam dumper D and a portion of the pumping light are not shown.

[0047] The second polarizing beam splitter PBS2 is disposed in the optical path of the linearly polarized seed light SB1. The seed light SB1 has a third polarization direction parallel to the paper surface of Fig. 5 and is P-polarized with respect to the optical thin film of the second polarizing beam splitter PBS2.

[0048] The second λ / 4 wave plate λ / 4P2 is disposed in the optical path of seed light SB5 emitted from the second end E2 of the laser amplification medium AMP and reflected by the dichroic mirror DM2. The seed light SB5 has a third polarization direction parallel to the paper surface of Figure 5, and the optical axis of the second λ / 4 wave plate λ / 4P2 is tilted at 45° with respect to the third polarization direction. A mechanism for rotating the second λ / 4 wave plate λ / 4P2 is not required.

[0049] The high-reflection mirror M6 is a concave mirror arranged in the optical path of the seed light SB6 that has passed through the second λ / 4 wave plate λ / 4P2. Instead of the high-reflection mirror M6, a combination of a plane mirror and a convex lens may be used.

[0050] 2.3.2 Operation The seed light SB1 passes through the second polarizing beam splitter PBS2 as seed light SB2, is reflected by the dichroic mirror DM1 as seed light SB3, and enters the first end E1 of the laser amplification medium AMP.

[0051] The seed light SB4, once amplified by the laser amplification medium AMP, is emitted from the second end E2, reflected by the dichroic mirror DM2 as seed light SB5, and transmitted through the second λ / 4 wave plate λ / 4P2, which converts the linearly polarized seed light SB5 into circularly polarized seed light SB6 and makes it incident on the high-reflection mirror M6.

[0052] The high-reflection mirror M6 reflects the seed light SB6 as seed light SB7. The seed light SB7 travels the same optical path as the seed lights SB6, SB5, and SB4 in the opposite direction as seed light SB7, SB8, and SB9 and returns to the second end E2. When the seed light SB7 passes through the second λ / 4 wave plate λ / 4P2 again, the second λ / 4 wave plate λ / 4P2 converts the circularly polarized seed light SB7 into linearly polarized seed light SB8. The polarization direction of the seed light SB8 becomes a fourth polarization direction perpendicular to the polarization direction of the seed light SB5.

[0053] The seed light SB9 incident on the laser amplification medium AMP is amplified again to produce laser light LB 10 The laser beam LB is emitted from the first end E1 as a 11 The laser beam LB is reflected by the second polarizing beam splitter PBS2. 11 The laser beam LB has a fourth polarization direction perpendicular to the paper surface of FIG. 5 and is S-polarized with respect to the optical thin film of the second polarizing beam splitter PBS2. 11 is reflected by the second polarizing beam splitter PBS2 as laser light LB and output from the laser amplifier 1b.

[0054] In other respects, the first modified example is similar to the first embodiment.

[0055] 2.4 Second Variant 6 shows the configuration of a laser amplifier 1c according to a second modification of the first embodiment. The laser amplifier 1c is an example of a double-ended pumped laser amplifier according to the present disclosure. The configuration and operation of the laser amplifier 1c are almost the same as those of the laser amplifier 1b, but differ in the following respects. The point where the optical paths of the seed light SB1 and the laser light LB are swapped and their traveling directions are reversed. Linearly polarized seed light SB1 to SB5, SB8, and SB9, and laser light LB 10 , L.B. 11 , and the point where the polarization direction of LB rotates by 90°. The point where the rotation direction of the circularly polarized seed light SB6 and SB7 is reversed.

[0056] 2.5 Effect (1) According to the first embodiment, a laser amplifier 1a includes a laser amplification medium AMP that amplifies a pulsed seed light SB1, a pump laser PL that outputs pumping light B1, a first λ / 4 wave plate λ / 4P1 and a first λ / 2 wave plate λ / 2P1 through which the pumping light B2 passes, a first polarizing beam splitter PBS1, and focus lenses FL1 and FL2. The first polarizing beam splitter PBS1 splits the pumping light B4 that has passed through the first λ / 4 wave plate λ / 4P1 and the first λ / 2 wave plate λ / 2P1 into a first light beam having a first polarization direction perpendicular to the plane of FIG. 2 and a second light beam having a second polarization direction parallel to the plane of FIG. 2. The focus lens FL1 causes the first light beam to be incident on a first end E1 of the laser amplification medium AMP, and the focus lens FL2 causes the second light beam to be incident on a second end E2 of the laser amplification medium AMP.

[0057] According to this, by defining the polarization state of the pumping light B4 by the first λ / 4 wave plate λ / 4P1 and the first λ / 2 wave plate λ / 2P1, it is possible to set the ratio of the light amounts of the first light and the second light, and the pumping light B4 incident on the laser amplification medium AMP can be 18 and B 37 In addition, the amount of pumping light B that is not absorbed in the laser amplification medium AMP can be set. 19 and B 38 This can prevent the pump laser PL from being damaged by the laser beam.

[0058] (2) According to the first embodiment, the laser amplifier 1a further includes a rotation mechanism AC2 that rotates the first λ / 2 wave plate λ / 2P1 so as to change the optical axis A2 of the first λ / 2 wave plate λ / 2P1.

[0059] According to this, by rotating the polarization direction of the excitation light B4, it is possible to change the ratio of the amount of the first light to the amount of the second light.

[0060] (3) According to the first embodiment, the laser amplifier 1a further includes a rotation mechanism AC1 that rotates the first λ / 4 wave plate λ / 4P1 so as to change the optical axis A1 of the first λ / 4 wave plate λ / 4P1.

[0061] According to this, by rotating the first λ / 4 wave plate λ / 4P1, the polarization state of the pumping light B3 can be changed, and the pumping light B 18 and B 37 The light intensity can be fine-tuned.

[0062] (4) According to the first and second modifications of the first embodiment, the laser amplifiers 1b and 1c further include a second polarizing beam splitter PBS2, a high-reflection mirror M6, and a second λ / 4 wave plate λ / 4P2. The second polarizing beam splitter PBS2 passes the linearly polarized seed light SB1 having a third polarization direction parallel to the plane of FIG. 5 or perpendicular to the plane of FIG. 6, and makes it incident on the first end E1. The high-reflection mirror M6 reflects the seed light SB6 emitted from the second end E2 back to the second end E2. The second λ / 4 wave plate λ / 4P2 is located in the optical path of the seed light SB5 between the second end E2 and the high-reflection mirror M6, and is arranged so that when the seed light SB5 passes from the second end E2 to the high-reflection mirror M6, the second λ / 4 wave plate λ / 4P2 converts linearly polarized light having a third polarization direction into circularly polarized light, and when the seed light SB7 passes from the high-reflection mirror M6 to the second end E2, the second λ / 4 wave plate λ / 4P2 converts the circularly polarized light into linearly polarized light having a fourth polarization direction perpendicular to the plane of the paper in Fig. 5 or parallel to the plane of the paper in Fig. 6. The second polarizing beam splitter PBS2 amplifies the linearly polarized seed light SB9 having the fourth polarization direction and converts it into the laser light LB output from the first end E1.11 The optical path of the

[0063] According to this, the seed light SB1 can be amplified twice in the laser amplification medium AMP to output high-energy laser light LB.

[0064] (5) According to the first embodiment, the first light and the second light have the same light intensity.

[0065] This allows the laser amplification medium AMP to be excited efficiently.

[0066] (6) According to the first embodiment, the laser amplification medium AMP is a Yb:YAG crystal, and the pumping light B1 includes a wavelength component of either 940 nm or 969 nm.

[0067] This allows the laser amplification medium AMP to efficiently absorb the energy of the pumping light B1.

[0068] (7) According to the first embodiment, the pumping light B1 is continuous wave light.

[0069] This allows the seed light SB1 to be amplified without matching the pulse timing between the pump light B1 and the seed light SB1.

[0070] 3. Laser amplifier 1d capable of adjusting the light intensities of the first and second lights 3.1 Configuration 7 shows the configuration of a laser amplifier 1d according to the second embodiment. The laser amplifier 1d is an example of a double-pumped laser amplifier according to the present disclosure. The laser amplifier 1d differs from the laser amplifier 1a according to the first embodiment in that it includes second and third λ / 2 wave plates λ / 2P2 and λ / 2P3, third and fourth polarizing beam splitters PBS3 and PBS4, and includes several beam dampers (not shown) instead of the beam damper D.

[0071] The second λ / 2 wave plate λ / 2P2 divides the excitation light B reflected by the first polarizing beam splitter PBS1 and the high-reflection mirror M1. 11The second λ / 2 wave plate λ / 2P2 is arranged in the optical path of the second λ / 2 wave plate λ / 2P2. The second λ / 2 wave plate λ / 2P2 is configured so that the direction of the optical axis A2 can be rotated by a rotation mechanism similar to the rotation mechanism AC2 described with reference to FIG. 4. The rotation mechanism that rotates the second λ / 2 wave plate λ / 2P2 corresponds to the third rotation mechanism in this disclosure.

[0072] The third polarizing beam splitter PBS3 splits the excitation light B 12 is placed in the optical path of

[0073] Figure 8 is a perspective view of the third polarizing beam splitter PBS3, showing in more detail the area inside the encircled line VIII shown in Figure 7. The mutually perpendicular X, Y, and Z directions are common to Figures 7 and 8. While the first and fourth polarizing beam splitters PBS1 and PBS4 include optical thin films that are perpendicular to the plane of the paper in Figure 7, the third polarizing beam splitter PBS3 includes an optical thin film that intersects non-perpendicularly with the plane of the paper in Figure 7, i.e., the YZ plane.

[0074] The third λ / 2 wave plate λ / 2P3 divides the excitation light B 30 The third λ / 2 wave plate λ / 2P3 is arranged in the optical path of the optical axis A2. The third λ / 2 wave plate λ / 2P3 is configured so that the direction of the optical axis A2 can be rotated by a rotation mechanism similar to the rotation mechanism AC2 described with reference to FIG. 4. The rotation mechanism that rotates the third λ / 2 wave plate λ / 2P3 corresponds to the fourth rotation mechanism in this disclosure.

[0075] The fourth polarizing beam splitter PBS4 splits the excitation light B 31 is placed in the optical path of

[0076] 3.2 Operation 3.2.1 Adjusting the light intensity of the first light Excitation light B 11 When the polarization direction of the excitation light B coincides with the direction of the optical axis A2 of the second λ / 2 wave plate λ / 2P2, 12 The polarization direction of the excitation light B 117. As shown in FIG. 8, the polarization component perpendicular to the paper surface of FIG. 7 is P-polarized with respect to the optical thin film of the third polarizing beam splitter PBS3, and the polarization direction of the excitation light B 13 The light is transmitted through the third polarizing beam splitter PBS3 as a

[0077] When the second λ / 2 wave plate λ / 2P2 is rotated, the excitation light B 12 The polarization direction of the excitation light B can be changed so that it is not perpendicular to the plane of the paper in FIG. 12 The polarization component parallel to the paper surface of FIG. 7 is S-polarized with respect to the optical thin film of the third polarizing beam splitter PBS3, and the excitation light B 14 The excitation light B is reflected by the third polarizing beam splitter PBS3. 14 A beam damper (not shown) is placed in the optical path of the excitation light B. 12 By adjusting the polarization direction of the excitation light B, the third polarizing beam splitter PBS3 13 and B 14 The splitting ratio of the pump light B is adjusted. 13 The light intensity is adjusted.

[0078] Excitation light B 13 A part of the pump light B is not absorbed in the laser amplifying medium AMP. 19 and is emitted from the second end E2 as excitation light B 23 The excitation light B may enter the fourth polarizing beam splitter PBS4. 23 has a polarization direction perpendicular to the paper surface of FIG. 7 and is S-polarized with respect to the optical thin film of the fourth polarizing beam splitter PBS4, so the excitation light B 24 Excitation light B is reflected as 24 A beam damper (not shown) is disposed in the optical path.

[0079] 3.2.2 Adjusting the intensity of the second light The adjustment of the amount of the second light beam differs from the adjustment of the amount of the first light beam in that a third λ / 2 wave plate λ / 2P3 and a fourth polarizing beam splitter PBS4 are used instead of the second λ / 2 wave plate λ / 2P2 and the third polarizing beam splitter PBS3. 30 When the polarization direction of the excitation light B coincides with the direction of the optical axis A2 of the third λ / 2 wave plate λ / 2P3, 31 The polarization direction of the excitation light B 30 In this case, the polarization direction of the pump light B 31 is P-polarized with respect to the optical thin film of the fourth polarizing beam splitter PBS4, and the excitation light B 32 The light is transmitted through the fourth polarizing beam splitter PBS4 as a beam splitter.

[0080] When the third λ / 2 waveplate λ / 2P3 is rotated, the excitation light B 31 The polarization direction of the excitation light B can be changed. 31 The polarization component perpendicular to the paper surface of Figure 7 is the excitation light B 33 The excitation light B is reflected by the fourth polarizing beam splitter PBS4. 33 A beam damper (not shown) is placed in the optical path of the excitation light B. 31 By adjusting the polarization direction of the excitation light B, 32 The light intensity is adjusted.

[0081] Excitation light B 32 A part of the pump light B is not absorbed in the laser amplifying medium AMP. 38 and is emitted from the first end E1 as excitation light B 42 The excitation light B may enter the third polarizing beam splitter PBS3 as 42 has a polarization direction parallel to the paper surface of FIG. 7 and is S-polarized with respect to the optical thin film of the third polarizing beam splitter PBS3, so as shown in FIG. 8, the excitation light B 43 Excitation light B is reflected as 43 A beam damper (not shown) is disposed in the optical path.

[0082] 3.3 Effect (8) According to the second embodiment, the laser amplifier 1d further includes a second λ / 2 wave plate λ / 2P2 located on the optical path of the first light between the first polarizing beam splitter PBS1 and the laser amplification medium AMP, and a third polarizing beam splitter PBS3 located on the optical path of the first light between the second λ / 2 wave plate λ / 2P2 and the laser amplification medium AMP.

[0083] According to this, by using the second λ / 2 wave plate λ / 2P2 and the third polarizing beam splitter PBS3, the light amount of the first light can be set independently from the second light.

[0084] (9) According to the second embodiment, the laser amplifier 1d further includes a rotation mechanism that rotates the second λ / 2 wave plate λ / 2P2 so as to change the optical axis A2 of the second λ / 2 wave plate λ / 2P2.

[0085] According to this, the excitation light B 12 By rotating the polarization direction of the first light, the amount of light of the first light can be changed independently from the second light.

[0086] (10) According to the second embodiment, the laser amplifier 1d further includes a third λ / 2 wave plate λ / 2P3 located on the optical path of the second light between the first polarizing beam splitter PBS1 and the laser amplification medium AMP, and a fourth polarizing beam splitter PBS4 located on the optical path of the second light between the third λ / 2 wave plate λ / 2P3 and the laser amplification medium AMP.

[0087] According to this, by using the third λ / 2 wave plate λ / 2P3 and the fourth polarizing beam splitter PBS4, the amount of light of the second light can be set independently from the amount of the first light.

[0088] (11) According to the second embodiment, the laser amplifier 1d further includes a rotation mechanism that rotates the third λ / 2 wave plate λ / 2P3 so as to change the optical axis A2 of the third λ / 2 wave plate λ / 2P3.

[0089] According to this, the excitation light B 31By rotating the polarization direction of the second light, the amount of light of the second light can be changed independently from the first light.

[0090] In other respects, the second embodiment is similar to the first embodiment. Alternatively, in the second embodiment, the seed light SB1 may be amplified twice to output the laser light LB, as in the first and second modifications of the first embodiment.

[0091] 4. Laser amplifier 1e including pump laser PL3 that outputs linearly polarized light 4.1 Configuration 9 shows the configuration of a laser amplifier 1e according to the third embodiment. The laser amplifier 1e is an example of a double-ended pumped laser amplifier according to the present disclosure, and includes a pump laser PL3 that outputs linearly polarized pump light instead of the pump laser PL. The laser amplifier 1e does not necessarily include the first λ / 4 wave plate λ / 4P1. The beam damper D is not shown.

[0092] 4.2 Operation The collimator lens CL emits linearly polarized excitation light B2. When the polarization direction of the excitation light B2 coincides with the direction of the optical axis A2 of the first λ / 2 wave plate λ / 2P1, the polarization direction of the excitation light B4 becomes the same as the polarization direction of the excitation light B2. The ratio of the S-polarized component to the P-polarized component for the optical thin film of the first polarizing beam splitter PBS1 is determined depending on the polarization direction of the excitation light B4. The S-polarized component of the excitation light B4 is polarized by the excitation light B2. 10 The P-polarized component is reflected as the pump light B 30 It passes through as

[0093] By rotating the first λ / 2 wave plate λ / 2P1 using the rotation mechanism AC2 (see Figure 4), the polarization direction of the excitation light B4 can be changed according to the direction of the optical axis A2. By adjusting the polarization direction of the excitation light B4, the ratio of S-polarized and P-polarized components for the optical thin film of the first polarizing beam splitter PBS1 can be adjusted.

[0094] 4.3 Effect (12) According to a third embodiment, a laser amplifier 1e includes a laser amplification medium AMP that amplifies a pulsed seed light SB1, a pump laser PL3 that outputs linearly polarized pump light B1, a first λ / 2 wave plate λ / 2P1 through which the pump light B2 passes, a first polarizing beam splitter PBS1, and focus lenses FL1 and FL2. The first polarizing beam splitter PBS1 splits the pump light B4 that has passed through the first λ / 2 wave plate λ / 2P1 into a first light beam having a first polarization direction perpendicular to the plane of FIG. 9 and a second light beam having a second polarization direction parallel to the plane of FIG. 9. The focus lens FL1 causes the first light beam to be incident on a first end E1 of the laser amplification medium AMP, and the focus lens FL2 causes the second light beam to be incident on a second end E2 of the laser amplification medium AMP.

[0095] According to this, by defining the polarization state of the linearly polarized pumping light B4 by the first λ / 2 wave plate λ / 2P1, it is possible to set the ratio of the light amounts of the first light and the second light, and the pumping light B4 incident on the laser amplification medium AMP 18 and B 37 In addition, the amount of pumping light B that is not absorbed in the laser amplification medium AMP can be set. 19 and B 38 This can prevent the pump laser PL from being damaged by the laser beam.

[0096] (13) According to the third embodiment, the laser amplifier 1e further includes a rotation mechanism AC2 that rotates the first λ / 2 wave plate λ / 2P1 so as to change the optical axis A2 of the first λ / 2 wave plate λ / 2P1.

[0097] According to this, by rotating the polarization direction of the excitation light B4, it is possible to change the ratio of the amount of the first light to the amount of the second light.

[0098] In other respects, the third embodiment is similar to the first embodiment. Alternatively, in the third embodiment, the seed light SB1 may be amplified twice to output the laser light LB, as in the first and second modifications of the first embodiment. Alternatively, in the third embodiment, the light intensities of the first and second lights may be individually adjustable, as in the second embodiment.

[0099] 5.Other 5.1 Electronic Devices Containing Interposer IP Fig. 10 is a schematic diagram showing the configuration of an electronic device, which includes an integrated circuit chip IC, an interposer IP, and a circuit board CS.

[0100] The integrated circuit chip IC is, for example, a chip in which an integrated circuit (not shown) is formed on a silicon substrate, and the integrated circuit chip IC is provided with a plurality of bumps ICB that are electrically connected to the integrated circuit.

[0101] The interposer IP includes an insulating substrate with a plurality of through holes (not shown), each of which has a conductor (not shown) electrically connecting the front and back of the substrate. One surface of the interposer IP is formed with a plurality of lands (not shown), each of which is connected to a bump ICB, and each of the lands is electrically connected to one of the conductors in the through holes. The other surface of the interposer IP is provided with a plurality of bumps IPB, and each of the bumps IPB is electrically connected to one of the conductors in the through holes.

[0102] A plurality of lands (not shown) are formed on one surface of the circuit board CS, and the circuit board CS is provided with a plurality of terminals that are electrically connected to the lands, respectively.

[0103] 11 is a flowchart showing a method for manufacturing an electronic device. In S1, laser processing and wiring formation are performed on an interposer substrate that constitutes an interposer IP. Laser processing of the interposer substrate includes forming through holes by irradiating the interposer substrate with laser light LB. Wiring formation includes forming a conductive film on the inner wall surface of the through holes formed in the interposer substrate. Through these steps, an interposer IP is manufactured.

[0104] In S2, the interposer IP is bonded to the integrated circuit chip IC. This step includes, for example, placing the bumps ICB of the integrated circuit chip IC on the lands of the interposer IP and electrically connecting the bumps ICB to the lands.

[0105] In S3, the interposer IP is bonded to the circuit board CS. This step includes, for example, placing the bumps IPB of the interposer IP on the lands of the circuit board CS and electrically connecting the bumps IPB to the lands.

[0106] 5.2 Supplementary Information The above description is intended to be illustrative rather than limiting. Thus, it will be apparent to one skilled in the art that modifications can be made to the disclosed embodiments without departing from the scope of the claims. It will also be apparent to one skilled in the art that the disclosed embodiments can be used in combination.

[0107] Terms used throughout this specification and claims should be construed as "open ended" unless expressly stated otherwise. For example, words such as "comprise," "have," "comprise," and "equip" should be construed as meaning "without excluding the presence of elements other than those listed." In addition, the modifier "a" should be construed as meaning "at least one" or "one or more." In addition, the term "at least one of A, B, and C" should be construed as "A," "B," "C," "A+B," "A+C," "B+C," or "A+B+C." Furthermore, it should be construed as including combinations of these with elements other than "A," "B," and "C."

Claims

1. a laser amplification medium that amplifies the pulsed seed light; an excitation light source that outputs excitation light; a first λ / 4 wave plate and a first λ / 2 wave plate through which the excitation light passes; a first polarizing beam splitter that separates the excitation light that has passed through the first λ / 4 wave plate and the first λ / 2 wave plate into a first light beam having a first polarization direction and a second light beam having a second polarization direction; a first incident optical system that makes the first light incident on a first end of the laser amplification medium; a second incident optical system that makes the second light incident on a second end of the laser amplification medium; A double-ended pumped laser amplifier comprising:

2. 2. The double-ended pumped laser amplifier according to claim 1, a first rotation mechanism that rotates the first λ / 2 wave plate so as to change the optical axis of the first λ / 2 wave plate; a double-ended pumped laser amplifier further comprising:

3. 2. The double-ended pumped laser amplifier according to claim 1, a second rotation mechanism that rotates the first λ / 4 wave plate so as to change the optical axis of the first λ / 4 wave plate; a double-ended pumped laser amplifier further comprising:

4. 2. The double-ended pumped laser amplifier according to claim 1, a second polarizing beam splitter that transmits the linearly polarized seed light having a third polarization direction and causes it to be incident on the first end; a high-reflection mirror that reflects the seed light emitted from the second end and returns it to the second end; a second λ / 4 wave plate located in an optical path of the seed light between the second end and the high-reflection mirror, and arranged to convert linearly polarized light having the third polarization direction into circularly polarized light when the seed light traveling from the second end to the high-reflection mirror is passed through, and to convert circularly polarized light into linearly polarized light having a fourth polarization direction when the seed light traveling from the high-reflection mirror to the second end is passed through; Furthermore, the second polarizing beam splitter is located in an optical path of a laser beam that is amplified from the seed light that is linearly polarized and has the fourth polarization direction and is output from the first end portion; Doubly pumped laser amplifier.

5. 2. The double-ended pumped laser amplifier according to claim 1, the first light and the second light have the same light intensity; Doubly pumped laser amplifier.

6. 2. The double-ended pumped laser amplifier according to claim 1, the laser amplification medium is a Yb:YAG crystal, The excitation light contains either a wavelength component of 940 nm or 969 nm. Doubly pumped laser amplifier.

7. 2. The double-ended pumped laser amplifier according to claim 1, The excitation light is continuous wave light. Doubly pumped laser amplifier.

8. 2. The double-ended pumped laser amplifier according to claim 1, a second λ / 2 wave plate located in the optical path of the first light between the first polarizing beam splitter and the laser amplification medium; a third polarizing beam splitter located in the optical path of the first light between the second λ / 2 wave plate and the laser amplification medium; a double-ended pumped laser amplifier further comprising:

9. 9. The double-ended pumped laser amplifier according to claim 8, a third rotation mechanism that rotates the second λ / 2 wave plate so as to change the optical axis of the second λ / 2 wave plate; a double-ended pumped laser amplifier further comprising:

10. 9. The double-ended pumped laser amplifier according to claim 8, a third λ / 2 wave plate located in the optical path of the second light between the first polarizing beam splitter and the laser amplification medium; a fourth polarizing beam splitter located in the optical path of the second light between the third λ / 2 wave plate and the laser amplification medium; a double-ended pumped laser amplifier further comprising:

11. 11. The double-ended pumped laser amplifier of claim 10, a fourth rotation mechanism that rotates the third λ / 2 wave plate so as to change the optical axis of the third λ / 2 wave plate; a double-ended pumped laser amplifier further comprising:

12. a laser amplification medium that amplifies the pulsed seed light; an excitation light source that outputs linearly polarized excitation light; a first λ / 2 wave plate through which the excitation light passes; a first polarizing beam splitter that separates the excitation light that has passed through the first λ / 2 wave plate into a first light beam having a first polarization direction and a second light beam having a second polarization direction; a first incident optical system that makes the first light incident on a first end of the laser amplification medium; a second incident optical system that makes the second light incident on a second end of the laser amplification medium; A double-ended pumped laser amplifier comprising:

13. 13. The double-ended pumped laser amplifier of claim 12, a first rotation mechanism that rotates the first λ / 2 wave plate so as to change the optical axis of the first λ / 2 wave plate; a double-ended pumped laser amplifier further comprising:

14. 13. The double-ended pumped laser amplifier of claim 12, a second polarizing beam splitter that transmits the linearly polarized seed light having a third polarization direction and causes it to be incident on the first end; a high-reflection mirror that reflects the seed light emitted from the second end and returns it to the second end; a λ / 4 wave plate located in an optical path of the seed light between the second end and the high-reflection mirror, the λ / 4 wave plate being arranged to convert linearly polarized light having the third polarization direction into circularly polarized light when the seed light traveling from the second end to the high-reflection mirror is passed through, and to convert circularly polarized light into linearly polarized light having a fourth polarization direction when the seed light traveling from the high-reflection mirror to the second end is passed through; Furthermore, the second polarizing beam splitter is located in an optical path of a laser beam that is amplified from the seed light that is linearly polarized and has the fourth polarization direction and is output from the first end portion; Doubly pumped laser amplifier.

15. 13. The double-ended pumped laser amplifier of claim 12, a second λ / 2 wave plate located in the optical path of the first light between the first polarizing beam splitter and the laser amplification medium; a third polarizing beam splitter located in the optical path of the first light between the second λ / 2 wave plate and the laser amplification medium; a double-ended pumped laser amplifier further comprising:

16. 16. The double-ended pumped laser amplifier of claim 15, a third rotation mechanism that rotates the second λ / 2 wave plate so as to change the optical axis of the second λ / 2 wave plate; a double-ended pumped laser amplifier further comprising:

17. 16. The double-ended pumped laser amplifier of claim 15, a third λ / 2 wave plate located in the optical path of the second light between the first polarizing beam splitter and the laser amplification medium; a fourth polarizing beam splitter located in the optical path of the second light between the third λ / 2 wave plate and the laser amplification medium; a double-ended pumped laser amplifier further comprising:

18. 18. The double-ended pumped laser amplifier of claim 17, a fourth rotation mechanism that rotates the third λ / 2 wave plate so as to change the optical axis of the third λ / 2 wave plate; a double-ended pumped laser amplifier further comprising:

19. A method for manufacturing an electronic device, comprising: a seed laser that outputs pulsed seed light; a laser amplification medium that amplifies the seed light; an excitation light source that outputs excitation light; a first λ / 4 wave plate and a first λ / 2 wave plate through which the excitation light passes; a first polarizing beam splitter that separates the excitation light that has passed through the first λ / 4 wave plate and the first λ / 2 wave plate into a first light beam having a first polarization direction and a second light beam having a second polarization direction; a first incident optical system that makes the first light incident on a first end of the laser amplification medium; a second incident optical system that makes the second light incident on a second end of the laser amplification medium; generating a laser beam by a laser device comprising: laser processing the interposer substrate with the laser light to fabricate an interposer; coupling the interposer and the integrated circuit chip together to electrically connect them; The interposer and the circuit board are coupled to each other to electrically connect them together. A method for manufacturing an electronic device, comprising:

20. A method for manufacturing an electronic device, comprising: a seed laser that outputs pulsed seed light; a laser amplification medium that amplifies the seed light; an excitation light source that outputs linearly polarized excitation light; a first λ / 2 wave plate through which the excitation light passes; a first polarizing beam splitter that separates the excitation light that has passed through the first λ / 2 wave plate into a first light beam having a first polarization direction and a second light beam having a second polarization direction; a first incident optical system that makes the first light incident on a first end of the laser amplification medium; a second incident optical system that makes the second light incident on a second end of the laser amplification medium; generating a laser beam by a laser device comprising: laser processing the interposer substrate with the laser light to fabricate an interposer; coupling the interposer and the integrated circuit chip together to electrically connect them; The interposer and the circuit board are coupled to each other to electrically connect them together. A method for manufacturing an electronic device, comprising:

Images