TWI693761B - Laser amplifying apparatus - Google Patents

Abstract

Provided is a laser amplifying apparatus. The laser amplifying apparatus includes a seed beam source configured to provide seed beams and a solid-state amplifier configured to amplify outputs of the seed beams. The solid-state amplifier includes: a laser medium; a pumping beam source configured to provide pumping beams that excite the laser medium; a pumping beam mirror configured to reflect the pumping beams having passed through the laser medium to the laser medium again; a plurality of dichroic mirrors configured to reflect the seed beams to allow the seed beams to pass through the laser medium in a path that is the same as a pumping path of the pumping beams; and a plurality of mirrors arranged in an optical path of the seed beams.

Description

Laser amplifying device

The invention relates to a laser amplifying device, and relates to a laser amplifying device using a solid-state amplifier to amplify an optical fiber seed laser.

In the semiconductor manufacturing process, the use of laser application technology is gradually expanding. Therefore, precision microfabrication of microelectronics industrial products and parts such as semiconductors, displays, printed circuit boards (PCBs), and smartphones is required. In the field, new laser processes invested in improving production efficiency and productivity have attracted much attention.

In the laser dicing process, when it is applied to a process with a nanometer size or less, problems such as an increase in capacitance, a time delay, an increase in power consumption, and mutual interference noise occur due to narrow wiring intervals. In order to solve the above problem, an interlayer insulating film is introduced on the surface of the semiconductor wafer. In this case, when the wafer is cut by the previous aluminum wheel method, the interlayer insulating film substance adheres to the surface of the diamond wheel. Therefore, it is preferable to use a laser device to engrave grooves on the surface of the semiconductor wafer, and cut the remaining part by the previous method.

In addition, in the PCB manufacturing process, it also promotes process development to improve production efficiency and productivity. In order to realize two kinds of ultraviolet drilling and cutting in one device For more than one process, two or more laser light sources with short pulses and long pulses are required. Recently, there is a need for a laser light source that can realize pulse width modulation.

The pulse width generation range of ultraviolet solid lasers crystallized using yttrium aluminum garnet (YAG) or yttrium vanadate (YVO ₄ ), which is currently commercialized, is mostly limited to tens of nanoseconds (ns). Therefore, there is a need for a laser light source with long pulses over hundreds of nanoseconds that can be applied to various processes such as laser grooving processes and PCB processes.

According to an exemplary embodiment of the present invention, there is provided a laser amplifying device which emits a laser having a pulse width of several nanoseconds (ns) to hundreds of nanoseconds (ns), which can be repeated at hundreds of kHz It can operate at a rate of several watts to tens of watts.

A laser amplifying device according to an embodiment of the present invention includes: a seed beam light source that supplies a seed beam; and a solid-state amplifier that amplifies the output of the seed beam; and the solid-state amplifier includes: a laser medium; a pump beam light source that supplies the excitation Pumping beam of laser medium; pumping beam mirror to make the pumping beam passing through the laser medium reflect again to the laser medium; a plurality of bidirectional color (dichroic) mirrors, along with the pumping of the seed beam The same pumping path of the light beam reflects the seed beam through the laser medium; and a plurality of mirrors are arranged on the light path of the seed beam.

The plurality of bidirectional color mirrors can reflect the seed beam and transmit the pump beam.

The bidirectional color mirror may include a first bidirectional color mirror and a second bidirectional color mirror, and the laser medium may be configured between the first bidirectional color mirror and the second bidirectional color mirror between.

The above-mentioned seed beam light source may be an optical fiber seed laser light source.

The laser amplifying device may further include a seed beam adjusting device that adjusts the characteristics of the seed beam emitted from the seed beam light source.

The aforementioned seed beam adjusting device may include a half-wave plate.

The seed beam adjusting device may include a first lens and a second lens, which are spaced apart from each other in the traveling direction of the seed beam, and adjust the beam diameter of the seed beam as the interval between them changes.

The first lens and the second lens can be configured such that the seed light beam passing through the second lens becomes parallel light.

The laser medium can amplify the seed beam into a signal beam.

The seed beam emitted from the seed beam light source may be a polarized laser beam.

The laser amplifying device of the exemplary embodiment utilizes an optical fiber seed laser, whereby the pulse width and repetition rate can be easily adjusted, and a solid-state amplifier can be used to output an output with a power of tens of watts to hundreds of watts. Laser.

In addition, it can improve the processing quality and productivity of laser application equipment, especially PCB equipment and grooving equipment.

In addition, a laser amplifying device can be used to achieve pulse width modulation and output amplification, so it can also produce advantageous effects in terms of miniaturization of equipment, reduction in equipment manufacturing costs, and maintenance.

100: laser amplifying device

110: Seed beam light source

120: Seed beam adjustment device

121: Half wave plate

123: the first lens

125: second lens

140: solid state amplifier

141: Pumping beam light source

145: Laser medium

147: Pumping beam mirror

d: distance

DM1: the first two-way color mirror

DM2: second bi-directional color mirror

M1, M2, M3: mirror

L: seed beam

P: Pumping beam

W1, W2: beam diameter

FIG. 1 is a laser amplifying device schematically showing an embodiment of the present invention Figure.

2a is a diagram schematically showing a seed beam adjusting device in a laser amplifying device according to an embodiment of the present invention.

FIG. 2b is an enlarged view of the first lens and the second lens in the seed beam adjusting device.

3 is a diagram schematically showing a solid-state amplifier in a laser amplifying device according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those with common knowledge in the technical field to which the present invention belongs can easily implement the present invention. However, the present invention can be implemented in various forms, and is not limited to the embodiments described here. In addition, in order to clearly explain the present invention, parts irrelevant to the description are omitted in the drawings, and similar parts are marked with similar symbols throughout the specification.

Throughout this specification, when it is stated that a part is "connected" to another part, it includes not only the case of "direct connection", but also "electrically connected" with "there are other elements spaced in between" situation. In addition, in the entire specification, when it is described that a certain part "includes" a certain constituent element, as long as there is no particular contrary description, it means that other constituent elements may be included, rather than excluding other constituent elements.

FIG. 1 is a diagram exemplarily showing a laser amplifying device 100 according to an embodiment of the present invention.

1, the laser amplifying device 100 includes a seed beam light source 110, Seed beam adjusting device 120 and solid-state amplifier 140.

The seed beam light source 110 emits a seed beam L, which may be, for example, a semiconductor laser diode, or a picosecond or femtosecond mode-locked fiber seed laser light source. The seed beam light source 110 can emit polarized laser light, and as a row, can emit a horizontally polarized seed beam. In the case of using an optical fiber seed laser light source as the seed beam light source 110, a seed beam having a pulse width of several nanoseconds to hundreds of nanoseconds can be released by pulse width modulation. In addition, the seed beam light source 110 can adjust the seed beam in a manner having a repetition rate of tens of kHz to hundreds of kHz.

The seed beam adjusting device 120 can adjust the characteristics of the seed beam L released from the seed beam light source. The configuration of the seed beam adjustment device 120 will be described later.

The solid-state amplifier 140 may amplify the output of the seed beam L emitted from the seed beam light source 110. The solid-state amplifier 140 may include a laser medium 145, a pump beam light source 141, a pump beam mirror 147, a plurality of bidirectional color mirrors DM1, DM2, and a plurality of mirrors M1, M2, M3. The detailed structure of the solid-state amplifier 140 will be described later in FIG. 3.

2a is a diagram schematically showing the seed beam adjusting device 120 in the laser amplifying device according to an embodiment of the present invention, and FIG. 2b is an enlarged view showing the first lens and the second lens in the seed beam adjusting device.

Referring to FIG. 2a, the seed beam adjustment device 120 may include a half-wave plate 121, first lenses, and second lenses 123, 125.

The half-wave plate 121 serves as a wave plate that causes the light traveling in the polarization direction along the slow axis to differ by a half-wavelength degree with respect to the fast axis, and can convert 45-degree linearly polarized light into horizontally polarized light and convert the horizontal The polarized light is converted into 45-degree linearly polarized light.

2b, the first lens and the second lens 123, 125 can be used in seed light The beams L are arranged spaced apart from each other in the traveling direction, and the beam diameter of the seed beam L is adjusted as the interval between the first lens and the second lens changes. The first lens 123 may be in a form close to a convex lens. Therefore, the first lens 123 can reduce the beam diameter of the incident seed beam L. As shown in FIG. 2b, the beam diameter W2 of the seed beam L emitted from the second lens may be smaller than the beam diameter W1 of the seed beam L incident on the first lens 123.

In addition, the second lens 125 may be in a form close to a concave lens. Therefore, the seed light beam L incident on the second lens 125 can be made close to parallel light. Also, although not shown, the seed beam adjustment device 120 may include a lens adjustment portion that adjusts the distance d between the first lens 123 and the second lens 125. The lens adjustment part can be controlled by a mechanical driving method or a manual method, and the distance d between the first lens 123 and the second lens 125 can be reduced or enlarged. By adjusting the distance d between the first lens 123 and the second lens 125 by the lens adjustment part, the beam diameter of the seed beam L can be appropriately changed. If the distance d between the first lens 123 and the second lens 125 becomes larger, the beam diameter of the seed beam L emitted through the second lens 125 becomes smaller, and if the distance between the first lens 123 and the second lens 125 As d becomes smaller, the beam diameter of the seed beam L emitted through the second lens 125 becomes larger.

For example, the beam diameter W1 of the seed beam L incident on the first lens 123 may be 2 nm to 3 nm, and the beam diameter W2 of the seed beam L emitted through the second lens may be 1 nm or less.

In the seed beam adjusting device 120, while maintaining parallel light, the range of adjusting the beam diameter is limited. In order to expand the adjustment range of the beam diameter using the seed beam adjustment device 120, the first lens and the second lens 123, 125 may be based on the output characteristics (seed beam diameter, divergence angle) and seed beam of the seed beam light source 110 The distance between the adjusting device 120 and the solid-state amplifier 140 constitutes an optimal lens combination. In addition, the seed beam adjusting device 120 may include more than 3 lenses according to circumstances.

FIG. 3 is a diagram schematically showing a solid-state amplifier 140 in a laser amplifying device according to an embodiment of the present invention.

Referring to FIG. 3, the solid-state amplifier 140 may amplify the output of the seed beam L emitted from the seed beam light source 110. The solid-state amplifier 140 may include a laser medium 145, a pump beam light source 141, a pump beam mirror 147, a first bidirectional color mirror DM1, a second bidirectional color mirror DM2, and a plurality of mirrors M1, M2, M3.

The laser medium 145 excites the ions in the medium by the pump beam P released from the pump beam source 141, thereby playing the role of amplifying the seed beam L.

The pump beam light source 141 can emit the pump beam P that excites the laser medium 145. The pump beam light source 141 can be arranged so that the pump beam P enters the laser medium 145.

The pump beam mirror 147 can be arranged such that the laser medium 145 is located between the pump beam source 141 and the pump beam mirror 147. The pumping light beam P released from the pumping light source 141 cannot be completely absorbed by the laser medium 145, and a part of the pumping light beam P that is not absorbed by the laser medium 145 in the pumping light beam P can be reflected by the laser medium 145 And again incident to the laser medium 145. Therefore, the pumping beam mirror 147 can play a role of increasing the ratio of the pumping light beam P released from the pumping beam light source 141 by the laser medium 145.

The first bidirectional color mirror DM1 and the second bidirectional color mirror DM2 can reflect the seed beam L, and can be arranged in such a manner that the seed beam L passes through the laser medium 145 along the same path as the travel path of the pump beam P.

The first bidirectional color mirror DM1 and the second bidirectional color mirror DM2 can reflect the seed beam L and transmit the pump beam P. Therefore, the pump beam P released from the pump beam source 141 can be absorbed by the laser medium 145 after transmitting the first bidirectional color mirror DM1. A part of the pump beam P that is not absorbed by the laser medium 145 can be reflected by the pump beam mirror 147 after passing through the second bidirectional color mirror DM2, and is absorbed by the laser medium 145 again through the second bidirectional color mirror DM2.

The seed beam L incident on the solid-state amplifier 140 can be incident on the first bidirectional color mirror DM1 after being reflected by the first mirror M1 and the second mirror M2. The seed beam L incident on the first bidirectional color mirror DM1 may be reflected by the first bidirectional color mirror DM1 and pass through the laser medium 145, and the seed beam L passing through the laser medium 145 and the pump beam P may have the same optical path. The seed beam L incident on the laser medium 145 can show an amplified output after passing through the laser medium 145 excited by the pumping beam P. For example, the seed beam L may show a watt output before passing through the laser medium 145, and may show an output of tens of watts to hundreds of watts after passing through the laser medium 145. In addition, the seed beam L is amplified by the laser medium 145 to function as a signal beam.

The signal beam amplified by the laser medium 145 can be incident on the third mirror M3 after being reflected by the second bidirectional color mirror DM2. The third mirror M3 reflects the signal beam, whereby the signal beam can be released to the outside of the solid-state amplifier 140.

The laser amplifying device 100 of the exemplary embodiment utilizes an optical fiber seed laser, whereby the pulse width and repetition rate can be easily adjusted. In addition, the solid-state amplifier 140 can be used to emit a laser having an output of tens of watts to hundreds of watts.

The above description of the present invention is an example, and those of ordinary knowledge in the technical field to which the present invention belongs should understand that the technical idea or essential features of the present invention may not be changed Easily transformed into other specific forms. Therefore, it should be understood that the embodiments described above are examples in all aspects and are not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, a component described as a distributed type may also be implemented in a combined form.

The scope of the present invention is defined by the scope of the patent application for invention described below, rather than the above detailed description, and all changes or modifications derived from the meaning, scope and equivalent concepts of the patent application scope of the invention should be interpreted as being included in the scope of the present invention.

100: laser amplifying device

110: Seed beam light source

120: Seed beam adjustment device

140: solid state amplifier

L: seed beam

Claims (9)

A laser amplifying device includes: a seed beam light source, which supplies a seed beam; and a solid-state amplifier, which amplifies the output of the seed beam; and the solid-state amplifier includes: a laser medium; a pump beam light source, which supplies the excitation of the laser Pumping beam of the shooting medium; pumping beam mirror to make the pumping beam passing through the laser medium reflect again to the laser medium; a plurality of bidirectional color mirrors, with the seed beam along the pumping beam The same pumping path reflects the seed beam through the laser medium and transmits the pumping beam; and a plurality of mirrors are arranged on the optical path of the seed beam. The laser amplifying device according to item 1 of the patent application scope, wherein the bidirectional color mirror includes a first bidirectional color mirror and a second bidirectional color mirror, and the laser medium is configured to the first bidirectional color mirror and the Between the second two-way color mirror. The laser amplifying device as described in item 1 of the patent application range, wherein the seed beam light source is an optical fiber seed laser light source. The laser amplifying device as described in item 3 of the patent application scope further includes a seed beam adjusting device that adjusts the characteristics of the seed beam released from the seed beam light source. The laser amplifying device as described in item 4 of the patent application range, wherein the seed beam adjusting device includes a half-wave plate. The laser amplifying device as described in item 5 of the patent application range, wherein the seed beam adjusting device includes a first lens and a second lens, which are arranged apart from each other in the traveling direction of the seed beam, as The interval between them changes to adjust the beam diameter of the seed beam. The laser amplifying device according to item 6 of the patent application scope, wherein the first lens and the second lens are configured such that the seed light beam passing through the second lens becomes parallel light. The laser amplifying device as described in item 1 of the patent application scope, wherein the laser medium amplifies the seed beam into a signal beam. The laser amplifying device according to item 1 of the patent application scope, wherein the seed beam emitted from the seed beam light source is polarized laser light.

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