Two-end excitation laser amplifier and manufacturing method of electronic device

Abstract

The invention provides a two-end excitation laser amplifier and a manufacturing method of an electronic device. A two-end excitation laser amplifier is provided with: a laser amplification medium that amplifies pulse-shaped seed light; an excitation light source that outputs excitation light; a first lambda / 4 wavelength plate and a first lambda / 2 wavelength plate through which the excitation light is transmitted; a first polarization beam splitter that splits the excitation light transmitted through the first [lambda] / 4 wavelength plate and the first [lambda] / 2 wavelength plate into first light in a first polarization direction and second light in a second polarization direction; a first incident optical system that causes the first light to be incident on a first end portion of the laser amplification medium; and a second incident optical system that causes second light to be incident on a second end portion of the laser amplification medium.

Description

Technical Field

[0001] The present invention relates to a two-end pumped laser amplifier and a method for manufacturing an electronic device. Background Art

[0002] In recent years, in semiconductor exposure apparatuses, with the miniaturization and high integration of semiconductor integrated circuits, higher resolution has been required. Therefore, the shortening of the wavelength of light emitted from an exposure light source has been promoted. For example, as a gas laser device for exposure, a KrF excimer laser device that emits laser light with an output wavelength of about 248 nm and an ArF excimer laser device that emits laser light with an output wavelength of about 193 nm are used.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] [Patent Document 1] U.S. Patent No. 5,412,683 Specification

[0006] [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2016-051897

[0007] [Patent Document 3] U.S. Patent Application Publication No. 2009 / 245304 Specification

[0008] Non-Patent Documents

[0009] [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 of the Invention

[0010] One aspect of the present disclosure relates to a two-end pumped laser amplifier including: a laser amplification medium that amplifies pulsed seed light; a pump light source that outputs pump light; a first λ / 4 wave plate and a first λ / 2 wave plate through which the pump light passes; a first polarization beam splitter that splits the pump light passing through the first λ / 4 wave plate and the first λ / 2 wave plate into first light in a first polarization direction and second light in a second polarization direction; a first incident optical system that causes the first light to enter a first end of the laser amplification medium; and a second incident optical system that causes the second light to enter a second end of the laser amplification medium.

[0011] One aspect of the present disclosure relates to a two-end pumped laser amplifier including: a laser amplification medium that amplifies pulsed seed light; a pump light source that outputs linearly polarized pump light; a first λ / 2 wave plate through which the pump light passes; a first polarization beam splitter that splits the pump light passing through the first λ / 2 wave plate into first light in a first polarization direction and second light in a second polarization direction; a first incident optical system that causes the first light to enter a first end of the laser amplification medium; and a second incident optical system that causes the second light to enter a second end of the laser amplification medium.

[0012] One aspect of the present disclosure relates to a method for manufacturing an electronic device, including the following steps: generating laser light using a laser device; performing laser processing on an interposer substrate using the laser light to fabricate an interposer; bonding the interposer to an integrated circuit chip to electrically connect them to each other; and bonding the interposer to a circuit substrate to electrically connect them to each other. The laser device includes: a seed laser that outputs pulsed seed light; a laser amplification medium that amplifies the seed light; a pump light source that outputs pump light; a first λ / 4 wave plate and a first λ / 2 wave plate through which the pump light passes; a first polarization beam splitter that splits the pump light passing through the first λ / 4 wave plate and the first λ / 2 wave plate into first light in a first polarization direction and second light in a second polarization direction; a first incident optical system that causes the first light to enter a first end of the laser amplification medium; and a second incident optical system that causes the second light to enter a second end of the laser amplification medium.

[0013] A method for manufacturing an electronic device according to an aspect of the present disclosure includes the following steps: generating laser light using a laser device; performing laser processing on an interposer substrate using the laser light to fabricate an interposer; bonding the interposer to an integrated circuit chip to electrically connect them to each other; and bonding the interposer to a circuit substrate to electrically connect them to each other. The laser device includes: 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 wavelength plate through which the excitation light passes; a first polarization beam splitter that separates the excitation light passing through 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 that causes the first light to enter a first end of the laser amplification medium; and a second incident optical system that causes the second light to enter a second end of the laser amplification medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Hereinafter, as an example only, several embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0015] Figure 1 Shows the structure of a laser processing system in a comparative example.

[0016] Figure 2 Shows the structure of a laser amplifier according to a first embodiment.

[0017] Figure 3 Shows the structure of a first λ / 4 wavelength plate.

[0018] Figure 4 Shows the structure of a first λ / 2 wavelength plate.

[0019] Figure 5 Shows the structure of a laser amplifier according to a first modification of the first embodiment.

[0020] Figure 6 Shows the structure of a laser amplifier according to a second modification of the first embodiment.

[0021] Figure 7 Shows the structure of a laser amplifier according to a second embodiment.

[0022] Figure 8 Is a perspective view of a third polarization beam splitter, showing in more detail Figure 7 The interior of the enclosed line VIII shown.

[0023] Figure 9 Shows the structure of a laser amplifier according to a third embodiment.

[0024] Figure 10 Schematically shows the structure of an electronic device.

[0025] Figure 11It is a flowchart showing a method for manufacturing an electronic device. Detailed implementation

[0026] <Content>

[0027] 1. Comparative example

[0028] 1.1 Structure

[0029] 1.2 Operation

[0030] 1.3 Problems of the comparative example

[0031] 2. Laser amplifier 1A that adjusts the splitting ratio by adjusting the polarization state

[0032] 2.1 Structure

[0033] 2.2 Operation

[0034] 2.3 First modification

[0035] 2.3.1 Structure

[0036] 2.3.2 Operation

[0037] 2.4 Second modification

[0038] 2.5 Function

[0039] 3. Laser amplifier 1D that can adjust the light amounts of the first light and the second light separately

[0040] 3.1 Structure

[0041] 3.2 Operation

[0042] 3.2.1 Adjustment of the light amount of the first light

[0043] 3.2.2 Adjustment of the light amount of the second light

[0044] 3.3 Function

[0045] 4. Laser amplifier 1e including a pump laser PL3 that outputs linearly polarized light

[0046] 4.1 Structure

[0047] 4.2 Operation

[0048] 4.3 Function

[0049] 5. Others

[0050] 5.1 Electronic device including an intermediate layer IP

[0051] 5.2 Supplementary

[0052] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The embodiments described below represent several examples of the present disclosure and do not limit the content of the present disclosure. In addition, all of the structures and operations described in each embodiment are not necessarily essential as the structures and operations of the present disclosure. Furthermore, the same reference numerals are assigned to the same components, and redundant descriptions are omitted.

[0053] 1. Comparative Example

[0054] 1.1 Structure

[0055] Figure 1 The structure of the laser processing system in the comparative example is shown. The comparative example of the present disclosure is a method known only to the applicant and not a publicly known example recognized by the applicant himself. The laser processing system includes a seed laser SL, a laser amplifier 1, and a laser irradiation device 2.

[0056] The seed laser SL is a laser oscillator that outputs pulsed seed light SB1. The wavelength of the seed light SB1 is, for example, about 1030 nm. The laser amplifier 1 amplifies the seed light SB1 and outputs pulsed laser light LB. The laser LB can also be converted to the 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 the laser LB onto a workpiece (not shown). The workpiece is, for example, an interposer substrate for manufacturing an interposer IP that relays the integrated circuit chip IC and the circuit substrate CS described later. Figure 10 to the integrated circuit chip IC and the circuit substrate CS described later.

[0057] 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.

[0058] The laser amplification medium AMP is, for example, a crystal of Yb:YAG (Ytterbium-doped Yttrium Aluminum Garnet).

[0059] The pump lasers PL1 and PL2 are excitation light sources that output excitation light and are composed of, for example, semiconductor lasers or solid-state lasers. The wavelength of the excitation light is set according to the absorption wavelength of the laser amplification medium AMP. When the laser amplification medium AMP is a crystal of Yb:YAG, the wavelength of the excitation light is set to any wavelength of 940 nm and 969 nm.

[0060] The end caps EC1 and EC2 are respectively disposed at the output ends of the optical fibers connected to the pump lasers PL1 and PL2.

[0061] The collimating lenses CL1 and CL2 are respectively disposed on the optical paths of the pump lights B1 and B5 emitted from the end caps EC1 and EC2. The focal lengths of the collimating lenses CL1 and CL2 are, for example, 12 mm.

[0062] The focusing lenses FL1 and FL2 are respectively disposed on the optical paths of the pump lights B2 and B6 emitted from the collimating lenses CL1 and CL2. The focal lengths of the focusing lenses FL1 and FL2 are, for example, 250 mm. The focusing lenses FL1 and FL2 respectively correspond to the first and second incident optical systems in the present invention.

[0063] The dichroic mirrors DM1 and DM2 are disposed obliquely with respect to the optical axis of the seed light SB1 output from the seed laser SL and the optical axes of the pump lights B 17 and B 36 respectively emitted from the focusing lenses FL1 and FL2. The dichroic mirrors DM1 and DM2 are configured to reflect the wavelength components included in the seed light SB1 and transmit the wavelength components included in the pump lights B 17 and B 36 respectively.

[0064] 1.2 Operation

[0065] The pump lights output from the pump lasers PL1 and PL2 are respectively emitted as the pump lights B1 and B5 from the end caps EC1 and EC2. Here, the pump lights B1 and B5 are divergent lights. The pump lights B1 and B5 are respectively converted into the pump lights B2 and B6 by the collimating lenses CL1 and CL2. Here, the pump lights B2 and B6 are parallel lights. The pump lights B2 and B6 are respectively converted into the pump lights B 17 and B 36 by the focusing lenses FL1 and FL2. Here, the pump lights B 17 and B 36 are convergent lights. Only the optical axes of the light beams are shown in each figure.

[0066] The pump light B 17 emitted from the focusing lens FL1 transmits through the dichroic mirror DM1 and is condensed as the pump light B 18 on the first end portion E1 of the laser amplification medium AMP. The pump light B 36 emitted from the focusing lens FL2 transmits through the dichroic mirror DM2 and is condensed as the pump light B 37 on the second end portion E2 of the laser amplification medium AMP. Preferably, the pump lights B 18 and B 37 incident on the laser amplification medium AMP are coaxial with each other. Coaxiality does not limit to the case where the optical axes of the two light beams are exactly the same, and includes errors within a practical range, for example, an error within 1°.

[0067] The seed light SB1 emitted from the seed laser SL is reflected by the dichroic mirror DM1 and enters the first end E1 as the seed light SB3.

[0068] The laser amplification medium AMP is excited by the pump lights B 18 and B 37 to amplify the seed light SB3. The amplified seed light SB3 is emitted from the second end E2 as the laser LB4.

[0069] The laser 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 LB.

[0070] The pump lights B 18 and B 37 are, for example, continuous-wave lasers. Alternatively, the pump lights B 18 and B 37 can also be pulsed lasers. In this case, synchronization control is performed to overlap the pulses of the seed light SB3 with the pulses of the pump lights B 18 and B 37 in the laser amplification medium AMP.

[0071] Preferably, the pump lights B 18 and B 37 are adjusted to have the same light quantity as each other. To adjust the light quantity of the pump lights B 18 and B 37 , for example, the applied voltages supplied to the pump lasers PL1 and PL2 are controlled respectively.

[0072] 1.3 Problems of the Comparative Example

[0073] Not all of the pump lights B 18 and B 37 are absorbed in the laser amplification medium AMP. The light in the pump light B 18 that is not absorbed by the laser amplification medium AMP is emitted from the second end E2, passes through the dichroic mirror DM2, the focusing lens FL2, and the collimating lens CL2, and enters the end cap EC2, which may damage the pump laser PL2. The light in the pump light B 37 that is not absorbed by the laser amplification medium AMP may also damage the pump laser PL1. Alternatively, due to the energy of these lights, the end caps EC1 and EC2 may be heated and damaged.

[0074] In addition, in the comparative example, it is sometimes difficult to set the light quantity of the pump lights B 18 and B 37 incident on the laser amplification medium AMP.

[0075] The embodiments described below relate to a two-end pumped laser amplifier that can suppress damage to the pump lasers PL1 and PL2 caused by pump light not absorbed by the laser amplification medium AMP, and can set the amount of pump light B incident on the laser amplification medium AMP. 18 and B 37 amount of light.

[0076] 2. Laser amplifier 1A that adjusts the splitting ratio by adjusting the polarization state

[0077] 2.1 Structure

[0078] Figure 2 FIG. shows the structure of the laser amplifier 1A according to the first embodiment. The laser amplifier 1A is an example of the two-end pumped laser amplifier in the present disclosure. The laser amplifier 1A includes a pump laser PL, an end cap EC, a collimating lens CL, a first quarter-wave plate λ / 4P1, a first half-wave plate λ / 2P1, a first polarization beam splitter PBS1, and high-reflection mirrors M1 to M5.

[0079] The pump laser PL, the end cap EC, and the collimating lens CL are the same as the pump laser PL1, the end cap EC1, and the collimating lens CL1 in the comparative example, respectively. The laser amplifier 1A may not include the pump laser PL2, the end cap EC2, and the collimating lens CL2. The laser amplifier 1A further includes focusing lenses FL1 and FL2, dichroic mirrors DM1 and DM2, and a laser amplification medium AMP, which are the same as the respective components described in the comparative example.

[0080] The first quarter-wave plate λ / 4P1 is disposed on the optical path of the pump light B2 emitted from the collimating lens CL.

[0081] Figure 3 FIG. shows the structure of the first quarter-wave plate λ / 4P1. The first quarter-wave plate λ / 4P1 imparts a phase difference of 1 / 4 of the wavelength λ of the pump light B2 between the polarization component parallel to the optical axis A1 and the polarization component perpendicular to the optical axis A1 in the incident pump light B2. Thus, the first quarter-wave plate λ / 4P1 changes the polarization state of the pump light B2 and emits it as pump light B3. The polarization state of the pump light B3 is determined by the polarization state of the pump light B2 and the direction of the optical axis A1. As an example, when the pump light B2 incident on the first quarter-wave plate λ / 4P1 includes a circular polarization component or an elliptical polarization component, the first quarter-wave plate λ / 4P1 sometimes emits pump light B3 including a linear polarization component. When the first quarter-wave plate λ / 4P1 is rotated as shown by the arrow θ1 by the rotation mechanism AC1, the direction of the optical axis A1 changes, and the polarization state of the pump light B3 is adjusted. The rotation mechanism AC1 corresponds to the second rotation mechanism in the present disclosure.

[0082] Referring again to Figure 2 , the first λ / 2 wavelength plate λ / 2P1 is disposed on the optical path of the excitation light B3 emitted from the first λ / 4 wavelength plate λ / 4P1. Alternatively, the positional relationship between the first λ / 4 wavelength plate λ / 4P1 and the first λ / 2 wavelength plate λ / 2P1 may be reversed.

[0083] Figure 4 FIG. shows the structure of the first λ / 2 wavelength plate λ / 2P1. The first λ / 2 wavelength plate λ / 2P1 imparts a phase difference of 1 / 2 of the wavelength λ of the excitation light B3 between the polarization components parallel to the optical axis A2 and the polarization components perpendicular to the optical axis A2 in the incident excitation light B3. Thereby, the first λ / 2 wavelength plate λ / 2P1 changes the polarization state of the excitation light B3 and emits it as the 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 inclined at an angle with respect to the polarization direction of the linearly polarized excitation light B3 incident on the first λ / 2 wavelength plate λ / 2P1, the first λ / 2 wavelength plate λ / 2P1 emits linearly polarized excitation light B4 whose polarization direction is inclined at an angle with respect to the polarization direction of the excitation light B3. When the first λ / 2 wavelength plate λ / 2P1 is rotated as shown by the arrow θ2 by the rotation mechanism AC2, 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 the present disclosure.

[0084] Referring again to Figure 2 , the first polarization beam splitter PBS1 includes an optical thin film that transmits the P-polarized light component and reflects the S-polarized light component. For example, if the polarization direction of the excitation light B4 is inclined at 45° with respect to the incident plane of the excitation light B4 incident on the optical thin film, the light amounts of the P-polarized light component and the S-polarized light component of the excitation light B4 are equal. In this case, the excitation light B 10 reflected by the first polarization beam splitter PBS1 and the excitation light B 30 transmitted through the first polarization beam splitter PBS1 have substantially the same light amount.

[0085] 2.2 Operation

[0086] The excitation light output from the pump laser PL is emitted as the excitation light B1 from the end cap EC, and is transmitted through the collimating lens CL and becomes the excitation light B2. The excitation light B2 passes through the first λ / 4 wavelength plate λ / 4P1 and the first λ / 2 wavelength plate λ / 2P1, and is emitted as the excitation light B4 with the polarization state adjusted. The first polarization beam splitter PBS1 separates the excitation light B4 into the excitation light B 10 and B 30 . The polarization direction of the excitation light B 10 is the same asFigure 2 The first polarization direction perpendicular to the paper surface of Figure 2 , the pump light B 30 The polarization direction of 30 is Figure 2 The second polarization direction parallel to the paper surface of Figure 2 .

[0087] The pump light B 10 Is reflected by the high - reflection mirrors M1, M2, and M3 respectively and serves as the pump light B 11 , B 15 And B 16 . The pump light B 16 Passes through the focusing lens FL1 and serves as the pump light B 17 , passes through the dichroic mirror DM1 and serves as the pump light B 18 , and is incident on the first end E1 of the laser amplification medium AMP.

[0088] The pump light B 30 Is reflected by the high - reflection mirrors M4 and M5 respectively and serves as the pump light B 34 And B 35 . The pump light B 35 Passes through the focusing lens FL2 and serves as the pump light B 36 , passes through the dichroic mirror DM2 and serves as the pump light B 37 , and is incident on the second end E2 of the laser amplification medium AMP.

[0089] The light from the pump light B 10 To the pump light B 18 And the light from the pump light B 30 To the pump light B 37 Respectively correspond to the first light and the second light in the present disclosure. Preferably, the light amounts of the first light and the second light are the same as each other. Here, the same does not only refer to the case of being exactly the same, but includes an error within 5%. In addition, preferably, the optical path lengths of the first light and the second light from the first polarization beam splitter PBS1 to the laser amplification medium AMP are the same as each other.

[0090] The pump light B 18 The light not absorbed by the laser amplification medium AMP in 18 sometimes exits from the second end E2 as the pump light B 19 , passes through the dichroic mirror DM2, the focusing lens FL2, and the high - reflection mirrors M5 and M4 as the pump light B 20 , B 21 And B 22 Propagates, and is incident on the first polarization beam splitter PBS1 as the pump light B 23 The pump light B 23 Has a polarization direction perpendicular to the paper surface of Figure 2 Figure 2 , and is S - polarized light for the optical thin film of the first polarization beam splitter PBS1, so it is reflected and serves as the pump light B 50. Thus, damage to the pump laser PL and the end cap EC can be suppressed. In the excitation light B 50 a beam damper D is disposed on the optical path.

[0091] Sometimes, the light in the excitation light B 37 that is not absorbed by the laser amplification medium AMP exits from the first end E1 as the excitation light B 38 and propagates through the dichroic mirror DM1, the focusing lens FL1, and the high reflection mirrors M3, M2, and M1 as the excitation lights B 39 , B 40 , B 41 and B 42 and is incident on the first polarization beam splitter PBS1 as the excitation light B 44 . The excitation light B 44 has a polarization direction parallel to the plane of the paper of Figure 2 and is P-polarized light with respect to the optical film of the first polarization beam splitter PBS1, and thus is transmitted as the excitation light B 50 . Thus, damage to the pump laser PL and the end cap EC can be suppressed.

[0092] The seed lights SB1 and SB3, and the lasers LB4 and LB are the same as in the comparative example.

[0093] In other aspects, the first embodiment is the same as the comparative example.

[0094] 2.3 First modification

[0095] 2.3.1 Structure

[0096] Figure 5 FIG. shows the structure of the laser amplifier 1B according to the first modification of the first embodiment. The laser amplifier 1B is an example of the two-end excitation laser amplifier in the present disclosure. The difference between the laser amplifier 1B and the laser amplifier 1A is that, as a structure for amplifying the seed light SB1 twice and outputting the laser LB, it includes a second polarization beam splitter PBS2, a second λ / 4 wavelength plate λ / 4P2, and a high reflection mirror M6. The illustration of the beam damper D and a part of the excitation light is omitted.

[0097] The second polarization beam splitter PBS2 is disposed on the optical path of the linearly polarized seed light SB1. The seed light SB1 has a third polarization direction parallel to the plane of the paper of Figure 5 and is P-polarized light with respect to the optical film of the second polarization beam splitter PBS2.

[0098] The second λ / 4 wavelength plate λ / 4P2 is disposed on the optical path of the seed light SB5 that exits from the second end E2 of the laser amplification medium AMP and is reflected by the dichroic mirror DM2. The seed light SB5 has a polarization direction parallel to the plane of the paper of Figure 5A third polarization direction parallel to the paper surface, and the direction of the optical axis of the second λ / 4 wavelength plate λ / 4P2 is inclined 45° with respect to the third polarization direction. There may also be no mechanism for rotating the second λ / 4 wavelength plate λ / 4P2.

[0099] The high reflector M6 is a concave mirror disposed on the optical path of the seed light SB6 that has passed through the second λ / 4 wavelength plate λ / 4P2. A combination of a plane mirror and a convex lens may also be used instead of the high reflector M6.

[0100] 2.3.2 Operation

[0101] The seed light SB1 passes through the second polarization beam splitter PBS2 and becomes the seed light SB2, is reflected by the dichroic mirror DM1 and enters the first end E1 of the laser amplification medium AMP as the seed light SB3.

[0102] The seed light SB4 that has been amplified once by the laser amplification medium AMP exits from the second end E2, is reflected by the dichroic mirror DM2 and becomes the seed light SB5, and passes through the second λ / 4 wavelength plate λ / 4P2. The second λ / 4 wavelength plate λ / 4P2 converts the linearly polarized seed light SB5 into a circularly polarized seed light SB6 and makes it incident on the high reflector M6.

[0103] The high reflector M6 reflects the seed light SB6 and becomes the seed light SB7. The seed light SB7 is on the same optical path as the seed lights SB6, SB5, and SB4, and passes back in the opposite direction as the seed lights SB7, SB8, and SB9 and returns to the second end E2. When the seed light SB7 passes through the second λ / 4 wavelength plate λ / 4P2 again, the second λ / 4 wavelength plate λ / 4P2 converts the circularly polarized seed light SB7 into a 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.

[0104] The seed light SB9 incident on the laser amplification medium AMP is amplified again and exits as the laser LB from the first end E1 10 and is reflected by the dichroic mirror DM1 and becomes the laser LB 11 , and enters the second polarization beam splitter PBS2. The laser LB 11 has a fourth polarization direction perpendicular to the Figure 5 paper surface, and is S-polarized light with respect to the optical thin film of the second polarization beam splitter PBS2. The laser LB 11 is reflected by the second polarization beam splitter PBS2 and becomes the laser LB, and is output from the laser amplifier 1B.

[0105] In other respects, the first modification is the same as the first embodiment.

[0106] 2.4 Second Modification

[0107] Figure 6 Shows the structure of the laser amplifier 1C, which is a second variant of the first embodiment. The laser amplifier 1C is an example of a two-end pumped laser amplifier in the present disclosure. The structure and operation of the laser amplifier 1C are substantially the same as those of the laser amplifier 1B, but differ in the following aspects.

[0108] · The optical paths of the seed light SB1 and the laser LB are swapped and the traveling directions are opposite.

[0109] · The linearly polarized seed lights SB1 to SB5, SB8, and SB9 and the lasers LB 10 、LB 11 and LB have their polarization directions rotated by 90° respectively.

[0110] · The rotation directions of the circularly polarized seed lights SB6 and SB7 are opposite.

[0111] 2.5 Function

[0112] (1) According to the first embodiment, the laser amplifier 1A includes: a laser amplification medium AMP that amplifies the pulsed seed light SB1; a pump laser PL that outputs the excitation light B1; a first λ / 4 wavelength plate λ / 4P1 and a first λ / 2 wavelength plate λ / 2P1 that transmit the excitation light B2; a first polarization beam splitter PBS1; and focusing lenses FL1 and FL2. The first polarization beam splitter PBS1 separates the excitation light B4 that has passed through the first λ / 4 wavelength plate λ / 4P1 and the first λ / 2 wavelength plate λ / 2P1 into a first light in a first polarization direction perpendicular to the plane of the paper and a second light in a second polarization direction parallel to the plane of the paper. The focusing lens FL1 makes the first light incident on the first end E1 of the laser amplification medium AMP, and the focusing lens FL2 makes the second light incident on the second end E2 of the laser amplification medium AMP. Figure 2 of the paper and a second light in a second polarization direction parallel to Figure 2 the plane of the paper.

[0113] Thus, by specifying the polarization state of the excitation light B4 by the first λ / 4 wavelength plate λ / 4P1 and the first λ / 2 wavelength plate λ / 2P1, the light quantity ratio of the first light to the second light can be set, and the light quantities of the excitation lights B 18 and B 37 incident on the laser amplification medium AMP can be set. In addition, it is possible to suppress the damage of the pump laser PL caused by the excitation lights B 19 and B 38 that are not absorbed by the laser amplification medium AMP.

[0114] (2) According to the first embodiment, the laser amplifier 1A further includes a rotation mechanism AC2 that rotates the first λ / 2 wavelength plate λ / 2P1 to change the optical axis A2 of the first λ / 2 wavelength plate λ / 2P1.

[0115] Thus, by rotating the polarization direction of the pump light B4, the light quantity ratio between the first light and the second light can be changed.

[0116] (3) According to the first embodiment, the laser amplifier 1A further includes a rotation mechanism AC1 that rotates the first λ / 4 wavelength plate λ / 4P1 to change the optical axis A1 of the first λ / 4 wavelength plate λ / 4P1.

[0117] Thus, by rotating the first λ / 4 wavelength plate λ / 4P1, the polarization state of the pump light B3 can be changed, and the pump lights B 18 and B 37 incident on the laser amplification medium AMP can be finely adjusted in light quantity.

[0118] (4) According to the first and second modification examples of the first embodiment, the laser amplifiers 1B and 1C further include a second polarization beam splitter PBS2, a high reflector M6, and a second λ / 4 wavelength plate λ / 4P2. The second polarization beam splitter PBS2 allows the linearly polarized seed light SB1 to pass through and enter the first end E1. The linearly polarized seed light SB1 has a third polarization direction parallel to the paper surface of Figure 5 or perpendicular to the paper surface of Figure 6 . The high reflector M6 reflects the seed light SB6 emitted from the second end E2 and returns it to the second end E2. The second λ / 4 wavelength plate λ / 4P2 is located on the optical path of the seed light SB5 between the second end E2 and the high reflector M6, and is configured to convert the linearly polarized light with the third polarization direction into circularly polarized light when allowing the seed light SB5 traveling from the second end E2 to the high reflector M6 to pass through, and convert the circularly polarized light into linearly polarized light with a fourth polarization direction perpendicular to the paper surface of Figure 5 or parallel to the paper surface of Figure 6 when allowing the seed light SB7 traveling from the high reflector M6 to the second end E2 to pass through. The second polarization beam splitter PBS2 is arranged on the optical path of the laser LB 11 in which the linearly polarized seed light SB9 with the fourth polarization direction is amplified and emitted from the first end E1.

[0119] Thus, the seed light SB1 can be amplified twice in the laser amplification medium AMP to output high-energy laser LB.

[0120] (5) According to the first embodiment, the first light and the second light have the same light quantity.

[0121] Thus, the laser amplification medium AMP can be efficiently excited.

[0122] (6) According to the first embodiment, the laser amplification medium AMP is a Yb:YAG crystal, and the pump light B1 includes any wavelength component of 940 nm and 969 nm.

[0123] Thus, the laser amplification medium AMP can efficiently absorb the energy of the pump light B1.

[0124] (7) According to the first embodiment, the pump light B1 is a continuous-wave light.

[0125] Thus, even if the pulse timing between the pump light B1 and the seed light SB1 is not synchronized, the seed light SB1 can be amplified.

[0126] 3. Laser amplifier 1D capable of separately adjusting the light amounts of the first light and the second light

[0127] 3.1 Structure

[0128] Figure 7 The structure of the laser amplifier 1D according to the second embodiment is shown. The laser amplifier 1D is an example of the two-end pumped laser amplifier in the present disclosure. The laser amplifier 1D includes a second λ / 2 wavelength plate λ / 2P2, a third λ / 2 wavelength plate λ / 2P3, a third polarization beam splitter PBS3, and a fourth polarization beam splitter PBS4. Different from the laser amplifier 1A of the first embodiment, the laser amplifier 1D includes a plurality of beam dampers (not shown) in place of the beam damper D.

[0129] The second λ / 2 wavelength plate λ / 2P2 is disposed on the optical path of the pump light B reflected by the first polarization beam splitter PBS1 and the high reflector M1. 11 The second λ / 2 wavelength plate λ / 2P2 is configured to be rotated by the same rotation mechanism as the rotation mechanism AC2 described with reference to Figure 4 so that the direction of the optical axis A2 can be rotated. The rotation mechanism for rotating the second λ / 2 wavelength plate λ / 2P2 corresponds to the third rotation mechanism in the present disclosure.

[0130] The third polarization beam splitter PBS3 is disposed on the optical path of the pump light B that has passed through the second λ / 2 wavelength plate λ / 2P2. 12 of the optical path.

[0131] Figure 8 is a perspective view of the third polarization beam splitter PBS3, showing in more detail Figure 7 the interior of the enclosed line VIII shown in Figure 7 and Figure 8 The X direction, Y direction, and Z direction perpendicular to each other are the same in Figure 7 and Figure 7 The first polarization beam splitter PBS1 and the fourth polarization beam splitter PBS4 include optical thin films perpendicular to the paper surface of Figure 7 and Figure 7 In contrast, the third polarization beam splitter PBS3 includes an optical thin film that intersects non-perpendicularly with the paper surface of Figure 7 i.e., the YZ plane.

[0132] The third λ / 2 wavelength plate λ / 2P3 is arranged on the optical path of the pumping light B that has passed through the first polarization beam splitter PBS1. 30 The third λ / 2 wavelength plate λ / 2P3 is configured to be rotated by the same rotation mechanism as the rotation mechanism AC2 described with reference Figure 4 so that the direction of the optical axis A2 can be rotated. The rotation mechanism that rotates the third λ / 2 wavelength plate λ / 2P3 corresponds to the fourth rotation mechanism in the present disclosure.

[0133] The fourth polarization beam splitter PBS4 is arranged on the optical path of the pumping light B that has passed through the third λ / 2 wavelength plate λ / 2P3. 31 of the optical path.

[0134] 3.2 Operation

[0135] 3.2.1 Adjustment of the light quantity of the first light

[0136] When the polarization direction of the pumping light B 11 is the same as the direction of the optical axis A2 of the second λ / 2 wavelength plate λ / 2P2, the polarization direction of the pumping light B 12 is the same as the polarization direction of the pumping light B 11 and is perpendicular to the paper surface of Figure 7 . As Figure 8 shown, the polarization light component perpendicular to the paper surface of Figure 7 is P-polarized light with respect to the optical thin film of the third polarization beam splitter PBS3, passes through the third polarization beam splitter PBS3, and serves as the pumping light B 13 .

[0137] When the second λ / 2 wavelength plate λ / 2P2 is rotated, the polarization direction of the pumping light B 12 can be changed according to the direction of the optical axis A2 and becomes not perpendicular to the paper surface of Figure 7 . The polarization light component parallel to the paper surface of 12 in the pumping light B Figure 7 is S-polarized light with respect to the optical thin film of the third polarization beam splitter PBS3, is reflected by the third polarization beam splitter PBS3, and serves as the pumping light B 14 . A beam damper (not shown) is arranged on the optical path of the pumping light B 14 . By adjusting the polarization direction of the pumping light B 12 , the splitting ratio of the third polarization beam splitter PBS3 to the pumping lights B 13 and B 14 is adjusted. As a result, the light quantity of the pumping light B 13 is adjusted.

[0138] Sometimes, a part of the pumping light B 13 is not absorbed by the laser amplification medium AMP and exits from the second end portion E2 as the pumping light B 19Emitted as pump light B 23 Incident on the fourth polarization beam splitter PBS4. The pump light B 23 Has a polarization direction perpendicular to the paper surface of Figure 7 For the optical thin film of the fourth polarization beam splitter PBS4, it is S-polarized light, so it is reflected as the pump light B 24 . A beam damper (not shown) is arranged on the optical path of the pump light B 24 .

[0139] 3.2.2 Light Quantity Adjustment of the Second Light

[0140] The difference in the light quantity adjustment of the second light from that of the first light is that the third λ / 2 wavelength plate λ / 2P3 and the fourth polarization beam splitter PBS4 are used instead of the second λ / 2 wavelength plate λ / 2P2 and the third polarization beam splitter PBS3. When the polarization direction of the pump light B 30 Is the same as the direction of the optical axis A2 of the third λ / 2 wavelength plate λ / 2P3, the polarization direction of the pump light B 31 Is the same as the polarization direction of the pump light B 30 . In this case, the pump light B 31 Is P-polarized light for the optical thin film of the fourth polarization beam splitter PBS4, and transmits through the fourth polarization beam splitter PBS4 as the pump light B 32 .

[0141] When the third λ / 2 wavelength plate λ / 2P3 is rotated, the polarization direction of the pump light B 31 Can be changed. The polarization light component perpendicular to the paper surface in the pump light B 31 Is reflected by the fourth polarization beam splitter PBS4 as the pump light B Figure 7 . A beam damper (not shown) is arranged on the optical path of the pump light B 33 . By adjusting the polarization direction of the pump light B 33 , the light quantity of the pump light B 31 Is adjusted. 32

[0142] Sometimes a part of the pump light B 32 Is not absorbed by the laser amplification medium AMP and is emitted from the first end E1 as the pump light B 38 , and is incident on the third polarization beam splitter PBS3 as the pump light B 42 . The pump light B 42 Has a polarization direction parallel to the paper surface of Figure 7 , and for the optical thin film of the third polarization beam splitter PBS3, it is S-polarized light, so it is reflected as shown in Figure 8 As the pump light B 43 . A beam damper (not shown) is arranged on the optical path of the pump light B 43 .

[0143] 3.3 Function

[0144] (8) According to the second embodiment, the laser amplifier 1D further includes: a second λ / 2 wavelength plate λ / 2P2, which is located on the optical path of the first light between the first polarization beam splitter PBS1 and the laser amplification medium AMP; and a third polarization beam splitter PBS3, which is located on the optical path of the first light between the second λ / 2 wavelength plate λ / 2P2 and the laser amplification medium AMP.

[0145] Accordingly, by using the second λ / 2 wavelength plate λ / 2P2 and the third polarization beam splitter PBS3, the light quantity of the first light can be set independently of the second light.

[0146] (9) According to the second embodiment, the laser amplifier 1D further includes a rotation mechanism that rotates the second λ / 2 wavelength plate λ / 2P2 to change the optical axis A2 of the second λ / 2 wavelength plate λ / 2P2.

[0147] Thus, by rotating the polarization direction of the pump light B 12 the light quantity of the first light can be changed independently of the second light.

[0148] (10) According to the second embodiment, the laser amplifier 1D further includes: a third λ / 2 wavelength plate λ / 2P3, which is located on the optical path of the second light between the first polarization beam splitter PBS1 and the laser amplification medium AMP; and a fourth polarization beam splitter PBS4, which is located on the optical path of the second light between the third λ / 2 wavelength plate λ / 2P3 and the laser amplification medium AMP.

[0149] Therefore, by using the third λ / 2 wavelength plate λ / 2P3 and the fourth polarization beam splitter PBS4, the light quantity of the second light can be set independently of the first light.

[0150] (11) According to the second embodiment, the laser amplifier 1D further includes a rotation mechanism that rotates the third λ / 2 wavelength plate λ / 2P3 to change the optical axis A2 of the third λ / 2 wavelength plate λ / 2P3.

[0151] Thus, by rotating the polarization direction of the pump light B 31 the light quantity of the second light can be changed independently of the first light.

[0152] In other respects, the second embodiment is the same as the first embodiment. Alternatively, in the second embodiment, the seed light SB1 can be amplified twice and the laser LB can be output in the same manner as in the first and second modified examples of the first embodiment.

[0153] 4. Laser Amplifier 1e Including a Pump Laser PL3 that Outputs Linearly Polarized Light

[0154] 4.1 Structure

[0155] Figure 9 Shows the structure of the laser amplifier 1e of the third embodiment. The laser amplifier 1e is an example of the two-end pumped laser amplifier in the present disclosure, and includes a pump laser PL3 that outputs linearly polarized pump light to replace the pump laser PL. The laser amplifier 1e may not include the first λ / 4 wavelength plate λ / 4P1. The illustration of the beam damper D is omitted.

[0156] 4.2 Operation

[0157] The collimating lens CL outputs linearly polarized pump light B2. When the polarization direction of the pump light B2 is consistent with the direction of the optical axis A2 of the first λ / 2 wavelength plate λ / 2P1, the polarization direction of the pump light B4 is the same as that of the pump light B2. According to the polarization direction of the pump light B4, the ratio of the S-polarized light component to the P-polarized light component of the optical thin film for the first polarization beam splitter PBS1 is determined. The S-polarized light component in the pump light B4 is reflected as the pump light B 10 , and the P-polarized light component is transmitted as the pump light B 30 .

[0158] When the first λ / 2 wavelength plate λ / 2P1 is rotated by the rotation mechanism AC2 (refer to Figure 4 ), the polarization direction of the pump light B4 can be changed according to the direction of the optical axis A2. By adjusting the polarization direction of the pump light B4, the ratio of the S-polarized light component and the P-polarized light component of the optical thin film for the first polarization beam splitter PBS1 can be adjusted.

[0159] 4.3 Function

[0160] (12) According to the third embodiment, the laser amplifier 1e includes: a laser amplification medium AMP that amplifies the pulsed seed light SB1; a pump laser PL3 that outputs linearly polarized pump light B1; a first λ / 2 wavelength plate λ / 2P1 that transmits the pump light B2; a first polarization beam splitter PBS1; and focusing lenses FL1 and FL2. The first polarization beam splitter PBS1 separates the pump light B4 that has passed through the first λ / 2 wavelength plate λ / 2P1 into a first light in a first polarization direction perpendicular to the paper surface of Figure 9 and a second light in a second polarization direction parallel to the paper surface of Figure 9 . The focusing lens FL1 makes the first light incident on the first end E1 of the laser amplification medium AMP, and the focusing lens FL2 makes the second light incident on the second end E2 of the laser amplification medium AMP.

[0161] Thus, by specifying the polarization state of the pump light B4 linearly polarized by the first λ / 2 wavelength plate λ / 2P1, the light quantity ratio between the first light and the second light can be set, and the pump light B incident on the laser amplification medium AMP can be set. 18 and B 37 quantity. In addition, it is possible to suppress the damage of the pump laser PL caused by the pump light B 19 and B 38 that is not absorbed by the laser amplification medium AMP.

[0162] (13) According to the third embodiment, the laser amplifier 1e further includes a rotation mechanism AC2 that rotates the first λ / 2 wavelength plate λ / 2P1 to change the optical axis A2 of the first λ / 2 wavelength plate λ / 2P1.

[0163] Thus, by rotating the polarization direction of the pump light B4, the light quantity ratio between the first light and the second light can be changed.

[0164] In other aspects, the third embodiment is the same as the first embodiment. Alternatively, in the third embodiment, the seed light SB1 may be amplified twice and the laser LB may be output in the same manner as in the first and second modification examples of the first embodiment. Alternatively, in the third embodiment, the light quantities of the first light and the second light may be adjusted separately in the same manner as in the second embodiment.

[0165] 5. Others

[0166] 5.1 Electronic device including an interposer IP

[0167] Figure 10 Schematically shows the structure of the electronic device. Figure 10 The illustrated electronic device includes an integrated circuit chip IC, an interposer IP, and a circuit board CS.

[0168] The integrated circuit chip IC is, for example, a chip on which an integrated circuit (not shown) is formed on a silicon substrate. A plurality of bumps ICB electrically connected to the integrated circuit are provided on the integrated circuit chip IC.

[0169] The interposer IP includes an insulating substrate formed with a plurality of through holes (not shown), and conductors (not shown) that electrically connect the front and back surfaces of the substrate are provided in each through hole. A plurality of pads (not shown) respectively connected to the bumps ICB are formed on one surface of the interposer IP, and each pad is electrically connected to any one of the conductors in the through hole. A plurality of bumps IPB are provided on the other surface of the interposer IP, and each bump IPB is electrically connected to any one of the conductors in the through hole.

[0170] On one surface of a circuit substrate CS, a plurality of pads (not shown) respectively connected to bumps IPB are formed. The circuit substrate CS includes a plurality of terminals respectively electrically connected to these pads.

[0171] Figure 11 FIG. is a flowchart showing a manufacturing method of an electronic device. In S1, laser processing and wiring formation of an interposer substrate constituting an interposer IP are performed. The laser processing of the interposer substrate includes forming a through hole by irradiating the interposer substrate with a laser LB. The wiring formation includes forming a conductive film on the inner wall surface of the through hole formed in the interposer substrate. The interposer IP is manufactured through such a process.

[0172] In S2, the interposer IP and the integrated circuit chip IC are joined. This step includes, for example, disposing the bumps ICB of the integrated circuit chip IC on the pads of the interposer IP and electrically connecting the bumps ICB and the pads.

[0173] In S3, the interposer IP and the circuit substrate CS are joined. This step includes, for example, disposing the bumps IPB of the interposer IP on the pads of the circuit substrate CS and electrically connecting the bumps IPB and the pads.

[0174] 5.2 Supplement

[0175] The above description is illustrative rather than restrictive. Therefore, it is obvious to those skilled in the art that the embodiments of the present disclosure can be changed without departing from the claims. In addition, it is obvious to those skilled in the art that the embodiments of the present disclosure can be used in combination.

[0176] Unless otherwise clearly stated, the terms used throughout this specification and the claims should be interpreted as "non-limiting" terms. For example, terms such as "including", "having", "possessing", "comprising" should be interpreted as "not excluding the existence of elements other than the recited elements". In addition, the modifier "one" should be interpreted as "at least one" or "one or more". In addition, the term "at least one of A, B, and C" should be interpreted as "A", "B", "C", "A + B", "A + C", "B + C", or "A + B + C". Furthermore, it should be interpreted as also including combinations with elements other than "A", "B", and "C".

Claims

1. A two-end pumped laser amplifier, comprising: A laser amplification medium that amplifies pulsed seed light; A pump light source that outputs pump light; A first λ / 4 wave plate and a first λ / 2 wave plate through which the pump light passes; A first polarization beam splitter that separates the pump light passing through the first λ / 4 wave plate and the first λ / 2 wave plate into first light in a first polarization direction and second light in 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.

2. The two-end pumped laser amplifier according to claim 1, wherein The two-end pumped laser amplifier further comprises a first rotation mechanism that rotates the first λ / 2 wave plate to change the optical axis of the first λ / 2 wave plate.

3. The two-end pumped laser amplifier according to claim 1, wherein, The two-end pumped laser amplifier further comprises a second rotation mechanism that rotates the first λ / 4 wave plate to change the optical axis of the first λ / 4 wave plate.

4. The two-end pumped laser amplifier according to claim 1, wherein, The two-end pumped laser amplifier further comprises: A second polarization beam splitter that allows linearly polarized seed light having a third polarization direction to pass through and makes it incident on the first end; A high reflector that reflects the seed light emitted from the second end and returns it to the second end; And A second λ / 4 wave plate that is located on the optical path of the seed light between the second end and the high reflector and is configured to convert linearly polarized light having the third polarization direction into circularly polarized light when allowing the seed light traveling from the second end toward the high reflector to pass through, and convert circularly polarized light into linearly polarized light having a fourth polarization direction when allowing the seed light traveling from the high reflector toward the second end to pass through, The second polarization beam splitter is located on the optical path of the laser light in which the seed light having the fourth polarization direction is amplified and emitted from the first end.

5. The two-end pumped laser amplifier according to claim 1, wherein, The first light and the second light have the same light quantity.

6. The two-end pumped laser amplifier according to claim 1, wherein, The laser amplification medium is a Yb:YAG crystal, and the pump light includes any wavelength component of 940 nm and 969 nm.

7. The two-end pumped laser amplifier according to claim 1, wherein, The pump light is continuous-wave light.

8. The two-end pumped laser amplifier according to claim 1, wherein, The two-end pumped laser amplifier further comprises: A second λ / 2 wave plate that is located on the optical path of the first light between the first polarization beam splitter and the laser amplification medium; and A third polarization beam splitter that is located on the optical path of the first light between the second λ / 2 wave plate and the laser amplification medium.

9. The two-end pumped laser amplifier according to claim 8, wherein, The two-end pumped laser amplifier further comprises a third rotation mechanism that rotates the second λ / 2 wave plate to change the optical axis of the second λ / 2 wave plate.

10. The two-end pumped laser amplifier according to claim 8, wherein, The two-end pumped laser amplifier further comprises: A third λ / 2 wave plate that is located on the optical path of the second light between the first polarization beam splitter and the laser amplification medium; and A fourth polarization beam splitter that is located on the optical path of the second light between the third λ / 2 wave plate and the laser amplification medium.

11. The two-end pumped laser amplifier according to claim 10, wherein, The two-end pumped laser amplifier further includes a fourth rotation mechanism that rotates the third λ / 2 wavelength plate to change the optical axis of the third λ / 2 wavelength plate.

12. A two-end pumped laser amplifier, comprising: A laser amplification medium that amplifies pulsed seed light; A pump light source that outputs linearly polarized pump light; A first λ / 2 wavelength plate through which the pump light passes; A first polarization beam splitter that splits the pump light passing through 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 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.

13. The two-end pumped laser amplifier according to claim 12, wherein, The two-end pumped laser amplifier further includes a first rotation mechanism that rotates the first λ / 2 wavelength plate to change the optical axis of the first λ / 2 wavelength plate.

14. The two-end pumped laser amplifier according to claim 12, wherein, The two-end pumped laser amplifier further includes: A second polarization beam splitter that allows linearly polarized seed light having a third polarization direction to pass through and makes it incident on the first end; A high reflector that reflects the seed light emitted from the second end and returns it to the second end; and A λ / 4 wavelength plate that is disposed on the optical path of the seed light between the second end and the high reflector and is configured to convert linearly polarized light having the third polarization direction into circularly polarized light when allowing the seed light traveling from the second end toward the high reflector to pass through, and convert circularly polarized light into linearly polarized light having a fourth polarization direction when allowing the seed light traveling from the high reflector toward the second end to pass through. The second polarization beam splitter is disposed on the optical path of the laser light in which the seed light having the fourth polarization direction is amplified and emitted from the first end.

15. The two-end pumped laser amplifier according to claim 12, wherein, The two-end pumped laser amplifier further includes: A second λ / 2 wavelength plate that is disposed on the optical path of the first light between the first polarization beam splitter and the laser amplification medium; and A third polarization beam splitter that is disposed on the optical path of the first light between the second λ / 2 wavelength plate and the laser amplification medium.

16. The two-end pumped laser amplifier according to claim 15, wherein, The two-end pumped laser amplifier further includes a third rotation mechanism that rotates the second λ / 2 wavelength plate to change the optical axis of the second λ / 2 wavelength plate.

17. The two-end pumped laser amplifier according to claim 15, wherein, The two-end pumped laser amplifier further includes: A third λ / 2 wavelength plate that is disposed on the optical path of the second light between the first polarization beam splitter and the laser amplification medium; and A fourth polarization beam splitter that is disposed on the optical path of the second light between the third λ / 2 wavelength plate and the laser amplification medium.

18. The two-end pumped laser amplifier according to claim 17, wherein The two-end pumped laser amplifier further includes a fourth rotation mechanism that rotates the third λ / 2 wavelength plate to change the optical axis of the third λ / 2 wavelength plate.

19. A method for manufacturing an electronic device, including the following steps: Generating laser light using a laser device; The interposer substrate is processed by the laser to fabricate an interposer; The interposer is bonded to the integrated circuit chip to be electrically connected to each other; and The interposer is bonded to the circuit substrate to be electrically connected to each other, The laser device includes: 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, and the excitation light passes through the first λ / 4 wave plate and the first λ / 2 wave plate; A first polarization beam splitter that separates the excitation light passing through the first λ / 4 wave plate and the first λ / 2 wave plate into first light in a first polarization direction and second light in 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.

20. A manufacturing method of an electronic device, including the following steps: Generating laser light using a laser device; The interposer substrate is processed by the laser to fabricate an interposer; The interposer is bonded to the integrated circuit chip to be electrically connected to each other; and The interposer is bonded to the circuit substrate to be electrically connected to each other, The laser device includes: 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, and the excitation light passes through the first λ / 2 wave plate; A first polarization beam splitter that separates the excitation light passing through the first λ / 2 wave plate into first light in a first polarization direction and second light in 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.

Images