Shutter-free femtosecond laser system

Abstract

Provided is a shutter-free femtosecond laser system comprising: a femtosecond light source that generates a femtosecond laser beam; a pulse picker that modulates the femtosecond laser beam to generate a pulsed laser beam; an auxiliary light source that generates an auxiliary pulsed laser beam and provides same through an axis of polarization different from that of the pulsed laser beam; a control module that generates a pulse-out signal for controlling the output of the pulsed laser beam and applies the signal to the pulse picker; and a main amplifier for amplifying at least one of the pulsed laser beam and the auxiliary pulsed laser beam, wherein the shutter-free femtosecond laser system operates without the shutter conventionally provided at the end of a laser system and uses the pulse picker to control whether laser output is produced.

Description

Shutter-free femtosecond laser system

[0001] The present disclosure relates to a femtosecond laser system, and more specifically, to a shutter-free femtosecond laser system.

[0002] Femtosecond laser light can be used in industrial settings for cutting semiconductor wafers and secondary battery electrodes. Femtosecond laser light can be modulated into laser light formed by a femtosecond laser pulse train, as well as having its repetition rate controlled by a pulse control signal. Pulsed laser light can reduce defects on the cutting surface of semiconductor wafers and secondary battery electrodes.

[0003] According to a conventional femtosecond laser system, a processing device provides a pulse-out signal that determines whether to output a laser, and a shutter can emit a laser according to this pulse-out signal. At this time, the emitted laser can be compressed by a compressor and emitted onto a workpiece in the form of a femtosecond pulse.

[0004] In such conventional femtosecond laser systems, the shutter that determines whether to output the laser can be applied as an Acousto-Optic Modulator (AOM) or an Electro-Optic Modulator (EOM). An AOM controls the intensity, frequency, and phase of an optical signal through a high-frequency signal and is primarily used when high-speed shuttering is required. An EOM can control the phase, amplitude, and frequency of the laser by changing optical characteristics through an electric field.

[0005] Meanwhile, such shutters had the problem of causing a significant amount of output loss, with optical loss reaching up to 50% in laser output. Accordingly, there is a need for the development of technology to solve the problem of laser output reduction while still performing the function of a shutter in a laser system.

[0006] The purpose of the embodiment disclosed in this disclosure is to provide a laser system configured to omit the shutter configured at the end of a conventional laser system and to control whether or not to output a laser using a pulse speaker.

[0007] In addition, the purpose of the embodiment disclosed in this disclosure is to provide a laser system configured to provide an auxiliary laser signal to a main amplifier in order to resolve the problem of damage to the main amplifier caused by configuring the laser output to be controlled using a pulse speaker.

[0008] The problems that this disclosure aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below.

[0009] A system according to the present disclosure for achieving the technical problem described above comprises: a femtosecond light source that generates femtosecond laser light; a pulse picker that modulates the femtosecond laser light to generate pulsed laser light; an auxiliary light source that generates auxiliary pulsed laser light and provides it through a polarization axis different from that of the pulsed laser light; a control module that generates a pulse out signal to control the output of the pulsed laser light and applies it to an external gate port of the pulse picker; and a main amplifier that amplifies either the pulsed laser light or the auxiliary pulsed laser light.

[0010] Meanwhile, the auxiliary light source can provide the auxiliary pulse laser light to the main amplifier to prevent damage to the main amplifier when the output of the pulse laser light is turned off according to the pulse out signal.

[0011] Additionally, it may further include a polarization module that adjusts and transmits the polarization axis of the laser light selected for processing among the pulsed laser light and the auxiliary pulsed laser light amplified by the main amplifier, and reflects and removes the remaining laser light.

[0012] Additionally, the apparatus further includes a coupler that splits the femtosecond laser light into a first femtosecond laser light and a second femtosecond laser light and provides them through different polarization axes; a first pulse picker that modulates the first femtosecond laser light to generate a first pulse laser light; a second pulse picker that modulates the second femtosecond laser light to generate a second pulse laser light; and a polarization beam combiner that combines the first pulse laser light and the second pulse laser light; wherein the control module generates a pulse out signal to output either the first pulse laser light or the second pulse laser light and applies it to the external gate port of the first and second pulse pickers, and the main amplifier can amplify either the first pulse laser light or the second pulse laser light.

[0013] Additionally, it may further include a polarization module that adjusts and transmits the polarization axis of the laser light selected for processing among the first pulse laser light and the second pulse laser light amplified by the main amplifier, and reflects and removes the remaining laser light.

[0014] In addition, the first pulse speaker and the second pulse speaker can adjust the pulse repetition rate of the first pulse laser light and the second pulse laser light to be the same according to a sink-out signal applied from the control module.

[0015] Additionally, the apparatus further includes a first preamplifier comprising a stretcher for adjusting the pulse width of the first femtosecond laser light; and a second preamplifier comprising a stretcher under different conditions for adjusting the pulse width of the second femtosecond laser light differently from the pulse width of the first femtosecond laser light; and accordingly, the first femtosecond laser light and the second femtosecond laser light have different pulse widths, and the first pulse picker and the second pulse picker can each adjust the pulse repetition rate differently according to the first sync-out signal and the second sync-out signal.

[0016] Meanwhile, the system according to the present disclosure may include: a first femtosecond light source that generates and provides a first femtosecond laser light; a second femtosecond light source that generates and provides a second femtosecond laser light through a polarization axis different from that of the first femtosecond light; a first pulse picker that modulates the first femtosecond laser light to generate a first pulse laser light; a second pulse picker that modulates the second femtosecond laser light to generate a second pulse laser light; a polarization beam combiner that combines the first pulse laser light and the second pulse laser light; a control module that generates a pulse out signal to cause either the first pulse laser light or the second pulse laser light to be output and applies it to the external gate port of the first and second pulse pickers; and a main amplifier that amplifies either the first pulse laser light or the second pulse laser light.

[0017] Meanwhile, the system according to the present disclosure may include: a first femtosecond light source that generates a first femtosecond laser light; a second femtosecond light source that generates a second femtosecond laser light; a first pulse picker that modulates the first femtosecond laser light to generate a first pulse laser light; a second pulse picker that modulates the second femtosecond laser light to generate a second pulse laser light; a wavelength multiplexer that combines the first pulse laser light and the second pulse laser light into different wavelength bands; a control module that generates a pulse out signal to cause either the first pulse laser light or the second pulse laser light to be output from the wavelength multiplexer and applies it to the external gate port of the first and second pulse pickers; and a main amplifier that amplifies either the first pulse laser light or the second pulse laser light.

[0018] Additionally, it may further include a pulse width compressor that compresses the laser light selected for processing among the first pulse laser light and the second pulse laser light amplified by the main amplifier and outputs it to a processing device, and blocks the output of the remaining laser light.

[0019] According to the above-described means for solving the problem of the present disclosure, while preventing damage to the amplification stage, it is possible to control the on / off of the laser output faster than a conventional shutter structure, maintain energy uniformly between pulses, and expect the effect of reducing laser output loss caused by the shutter.

[0020] The effects of the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description below.

[0021] FIG. 1 is a drawing showing a shutter-free femtosecond laser system according to one embodiment of the present disclosure.

[0022] Figure 2 is a diagram showing an example of signals occurring in the system illustrated in Figure 1.

[0023] FIG. 3 is a drawing showing a shutter-free femtosecond laser system according to another embodiment of the present disclosure.

[0024] FIG. 4 is a drawing showing a shutter-free femtosecond laser system according to another embodiment of the present disclosure.

[0025] Figure 5 is a diagram showing an example of signals occurring in the system illustrated in Figure 4.

[0026] FIG. 6 is a drawing showing a shutter-free femtosecond laser system according to another embodiment of the present disclosure.

[0027] FIG. 7 is a drawing showing a shutter-free femtosecond laser system according to another embodiment of the present disclosure.

[0028] FIG. 8 is a diagram showing an example of the first wavelength band and the second wavelength band illustrated in FIG. 7.

[0029] Figures 9 and 10 are drawings showing the pulse width compressor illustrated in Figure 7.

[0030] Throughout this disclosure, the same reference numerals denote the same components. This disclosure does not describe all elements of the embodiments, and general content in the art to which this disclosure pertains or content that overlaps between embodiments is omitted. The terms 'part, module, component, block' as used in the specification may be implemented in software or hardware, and depending on the embodiments, a plurality of 'parts, modules, components, blocks' may be implemented as a single component, or a single 'part, module, component, block' may include a plurality of components.

[0031] Throughout the specification, when a part is described as being "connected" to another part, this includes not only cases where they are directly connected but also cases where they are indirectly connected, and indirect connections include connections made via a wireless communication network.

[0032] Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0033] Throughout the specification, when it is stated that a component is located "on" another component, this includes not only cases where a component is in contact with another component, but also cases where another component exists between the two components.

[0034] The terms first, second, etc. are used to distinguish one component from another, and the components are not limited by the aforementioned terms.

[0035] Singular expressions include plural expressions unless there is an obvious exception in the context.

[0036] In each step, identification codes are used for convenience of explanation and do not describe the order of the steps; the steps may be performed differently from the specified order unless a specific order is clearly indicated in the context.

[0037] The operating principles and embodiments of the present disclosure will be described below with reference to the attached drawings.

[0038] In this specification, the term "device according to the present disclosure" includes all various devices capable of performing computational processing and providing results to a user. For example, the device according to the present disclosure may include all of a computer, a server device, and a portable terminal, or may be in the form of any one of these.

[0039] Here, the computer may include, for example, a notebook, desktop, laptop, tablet PC, slate PC, etc. equipped with a web browser.

[0040] The above server device is a server that processes information by communicating with an external device, and may include an application server, a computing server, a database server, a file server, a game server, a mail server, a proxy server, and a web server.

[0041] The above portable terminal may include, for example, all types of handheld-based wireless communication devices such as PCS (Personal Communication System), GSM (Global System for Mobile communications), PDC (Personal Digital Cellular), PHS (Personal Handyphone System), PDA (Personal Digital Assistant), IMT (International Mobile Telecommunication)-2000, CDMA (Code Division Multiple Access)-2000, W-CDMA (W-Code Division Multiple Access), WiBro (Wireless Broadband Internet) terminals, smartphones, etc., as well as wearable devices such as watches, rings, bracelets, anklets, necklaces, glasses, contact lenses, or head-mounted devices (HMDs).

[0042] The functions related to artificial intelligence according to the present disclosure are operated through a processor and memory. The processor may be composed of one or more processors. In this case, the one or more processors may be general-purpose processors such as CPUs, APs, and DSPs (Digital Signal Processors), graphics-dedicated processors such as GPUs and VPUs (Vision Processing Units), or artificial intelligence-dedicated processors such as NPUs. The one or more processors control the processing of input data according to predefined operation rules or artificial intelligence models stored in memory. Alternatively, if the one or more processors are artificial intelligence-dedicated processors, the artificial intelligence-dedicated processors may be designed with a hardware structure specialized for processing a specific artificial intelligence model.

[0043] FIG. 1 is a drawing showing a shutter-free femtosecond laser system according to one embodiment of the present disclosure.

[0044] Referring to FIG. 1, a shutter-free femtosecond laser system (100) according to one embodiment of the present disclosure may include a femtosecond light source (10), a pre-amplifier (20), a pulse picker (30), an auxiliary light source (40), a main amplifier (50), a polarization module (60), a compressor (70), and a control module (80).

[0045] The femtosecond light source (10) can generate femtosecond laser light.

[0046] Femtosecond laser light can have a frequency of about 10 MHz to about 1000 MHz.

[0047] The preamplifier (20) can be connected to the femtosecond light source (10).

[0048] The preamplifier (20) can amplify femtosecond laser light.

[0049] The pulse speaker (30) can be connected to the preamplifier (20).

[0050] The pulse picker (30) can generate pulsed laser light by modulating femtosecond laser light. Pulsed laser light refers to femtosecond laser light having an arbitrary pulse train.

[0051] In the present invention, the pulse picker (30) may include a pulse delay generator (PD) and an AOM.

[0052] The pulse delay generator (PD) can perform the role of signal processing by selecting the femtosecond signal output from the femtosecond light source (10) and binding the external gate signal (pulse out signal). The AOM can perform the role of a switch that determines whether to output laser light.

[0053] The auxiliary light source (40) can be connected to the main amplifier (50).

[0054] The auxiliary light source (40) can generate auxiliary pulsed laser light. The auxiliary pulsed laser light may be femtosecond laser light, picosecond laser light, or nanosecond laser light having any pulse train.

[0055] The auxiliary light source (40) may be configured in the same way as the main laser stage including the femtosecond light source (10) and pre-amplifier (20) according to one embodiment of the present disclosure.

[0056] The auxiliary light source (40) provides auxiliary pulse laser light to the main amplifier (50), and can provide auxiliary pulse laser light through a polarization axis different from the polarization axis of the pulse laser light provided from the pulse picker (30).

[0057] In the following description, we will use an example where the pulsed laser light is provided through the slow axis of the optical fiber and the auxiliary pulsed laser light is provided through the fast axis of the optical fiber.

[0058] The auxiliary light source (40) provides auxiliary pulse laser light to the main amplifier (50), and when the output of the pulse laser light from the pulse speaker (30) to the main amplifier (50) is turned off due to the shutter action of the pulse speaker (30), the auxiliary pulse laser light can be provided to the main amplifier (50).

[0059] According to the present disclosure, the configuration of the shutter provided at the rear end of the main amplifier (50) is omitted, and the pulse speaker (30) acts as the shutter. Consequently, damage to the main amplifier (50) may occur because a continuous laser signal is not input to the main amplifier (50). At this time, the auxiliary light source (40) can prevent damage to the main amplifier (50) by providing auxiliary pulse laser light to the main amplifier (50). A detailed explanation regarding this will be provided later.

[0060] The main amplifier (50) can be connected to the pulse speaker (30) and the auxiliary light source (40).

[0061] The main amplifier (50) can amplify and output either the pulsed laser light or the auxiliary pulsed laser light.

[0062] The polarization module (60) can be connected to the main amplifier (50).

[0063] The polarization module (60) can transmit either the pulsed laser light or the auxiliary pulsed laser light output from the main amplifier (50), and reflect and remove the remaining laser light. Here, the laser light transmitted through the polarization module (60) can be compressed by a pulse width compressor (70) and provided to a processing device.

[0064] For example, the polarization module (60) can transmit the laser light selected for processing among the pulsed laser light and auxiliary pulsed laser light according to a control signal from the control module (80), and remove the remaining laser light by reflecting it in a different direction. That is, the polarization module (60) can transmit the pulsed laser light output from the main amplifier (50) and remove the auxiliary pulsed laser light by reflecting it. Or, conversely, the polarization module (60) can transmit the auxiliary pulsed laser light output from the main amplifier (50) and remove the pulsed laser light by reflecting it.

[0065] The polarization module (60) can adjust the polarization axis of the laser light selected for processing among the pulsed laser light and auxiliary pulsed laser light and transmit it to the pulse width compressor (70), and can remove the remaining laser light by reflecting it in a different direction. To this end, the polarization module (60) may include a polarization plate (61) and a polarization beam splitter (65).

[0066] A polarizing plate (HWP: Half Wave Plate) (61) can change the direction of the polarization axis of laser light through an optical fiber.

[0067] For example, the polarization plate (61) can adjust the polarization axis of the laser light selected for processing among the pulsed laser light and the auxiliary pulsed laser light to align with the axial direction of the pulse width compressor (70).

[0068] The polarizing beam splitter (65) can transmit or reflect laser light in a different direction depending on the polarization state of the laser light passing through the polarizing plate (61) after the optical fiber output end.

[0069] For example, the polarizing beam splitter (65) can transmit laser light that matches the polarization direction of the pulse width compressor (70) as is and provide it to the pulse width compressor (70), and can remove laser light that is perpendicular to the polarization direction of the pulse width compressor (70) by reflecting it perpendicular to the angle of incidence. That is, the polarizing beam splitter (65) can transmit the laser light selected for processing by the polarizing plate (61) among the pulse laser light and auxiliary pulse laser light as is and provide it to the pulse width compressor (70), and can provide the remaining laser light by reflecting it.

[0070] The pulse width compressor (70) can be connected to the polarization module (60).

[0071] The pulse width compressor (70) can compress the pulse width of the laser light provided by passing through the polarization module (60) and provide it to the processing device.

[0072] For example, the pulse width compressor (70) can compress the pulse width of the laser light selected for processing among the pulse laser light and auxiliary pulse laser light into a femtosecond or picosecond band and output it to the processing device.

[0073] The control module (80) may include a memory that stores data for an algorithm or a program that reproduces the algorithm for controlling the operation of components within the system, and at least one processor that performs the aforementioned operation using the data stored in the memory. Here, the memory and the processor may each be provided as separate chips. Additionally, the memory and the processor may be provided as a single chip.

[0074] The control module (80) can control the output of pulsed laser light to the main amplifier (50) by controlling the femtosecond light source (10), the pre-amplifier (20), and the pulse speaker (30). Additionally, the control module (80) can selectively control the pulsed laser light and the auxiliary pulsed laser light by controlling the polarization module (60). This will be explained with reference to FIG. 2.

[0075] Figure 2 is a diagram showing an example of signals occurring in the system illustrated in Figure 1.

[0076] For example, the control module (80) may receive a trigger signal (1) in which a femtosecond oscillator signal is converted into an electrical signal from the pre-amplifier (20). The pre-amplifier (20) may increase the pulse width of the femtosecond laser light and amplify it to provide a portion of the signal as the trigger signal (1) to the control module (80). The sink-out signal (3) is a signal corresponding to 1 / n of the femtosecond laser light or the trigger signal (1), as shown in FIG. 2, where n is a repetition rate factor of the femtosecond laser light and can be set by the control module (80) or the user.

[0077] The control module (80) can provide a sync-out signal (3) to the pulse speaker (30) to enable the repetition rate to be adjusted according to the trigger signal (1). Here, the pulse speaker (30) can generate pulsed laser light with the pulse repetition rate of the femtosecond laser light adjusted to 1 / n according to the sync-out signal (3).

[0078] The control module (80) can provide a pulse out signal (9) to the pulse picker (30) to control the on or off of the pulse laser light output from the processing equipment. For example, the control module (80) can set the on or off of the pulse laser light output according to the processing position in the processing process performed in the processing device, and can generate a pulse out signal (9) according to the setting and provide it to the pulse picker (30). Here, as shown in FIG. 2, the pulse picker (30) can generate and output pulse laser light according to the AOM application signal generated by multiplying the pulse out signal (9) by the sink out signal (3). Referring to FIG. 2, it can be seen that the pulse repetition rate and output status of the pulse laser light from the pulse picker (30) are controlled according to the AOM application signal. That is, when the pulse out signal (9) is on, the pulse picker (30) can output pulse laser light and provide it to the main amplifier (50).

[0079] In this way, the control module (80) can control the output of pulsed laser light from the pulse picker (30) according to the processing process of the processing device by generating a pulse out signal (9) that controls the on or off of the pulsed laser light output from the pulse picker (30) and providing it to the pulse picker (30).

[0080] Meanwhile, the main amplifier (50) can receive and amplify pulse laser light from the pulse speaker (30) when the pulse out signal (9) is on, and receive and amplify auxiliary pulse laser light from the auxiliary light source (40) when the pulse out signal (9) is off.

[0081] That is, the auxiliary light source (40) can provide auxiliary pulse laser light to the main amplifier (50) to prevent damage to the main amplifier (50) when the output of the pulse laser light from the pulse speaker (30) is turned off according to the pulse out signal (9).

[0082] Meanwhile, the control module (80) can control the polarization module (60) to control the laser light selected for processing among the pulsed laser light and auxiliary pulsed laser light amplified by the main amplifier (50) to be transmitted.

[0083] The control module (80) can set the laser light to be used for processing among the pulsed laser light and the auxiliary pulsed laser light. For example, the control module (80) can select the laser light for processing on the system according to the processing process in the processing device. At this time, the remaining laser light that is not selected for processing among the pulsed laser light and the auxiliary pulsed laser light will be used as a dummy to prevent damage to the main amplifier (50).

[0084] The control module (80) can provide a selection signal to the polarization module (60) to control the polarization axis of the laser light selected for processing among the pulsed laser light and the auxiliary pulsed laser light so that it can be transmitted.

[0085] For example, when a pulsed laser light having a slow polarization axis is selected as the processing laser light, the polarization module (60) can transmit the pulsed laser light output from the main amplifier (50) as is and reflect and remove the auxiliary pulsed laser light. Alternatively, when an auxiliary pulsed laser light having a fast polarization axis is selected as the processing laser light, the polarization module (60) can transmit the auxiliary pulsed laser light output from the main amplifier (50) by aligning its polarization axis with the polarization axis of the pulse width compressor (70), and adjust the polarization axis of the pulsed laser light to another axis and reflect and remove it.

[0086] A shutter-free femtosecond laser system (100) according to one embodiment of the present disclosure controls the laser output through a pulse picker (30), and is configured so that a laser signal is continuously input to a main amplifier (50) through an auxiliary light source (40) regardless of the laser output from the pulse picker (30), thereby preventing damage to the amplification stage, enabling faster on / off control of the laser output than a conventional shutter structure, maintaining energy between pulses uniformly, and expecting the effect of reducing laser output loss caused by the shutter.

[0087] FIG. 3 is a drawing showing a shutter-free femtosecond laser system according to another embodiment of the present disclosure.

[0088] Referring to FIG. 3, a shutter-free femtosecond laser system (101) according to another embodiment of the present disclosure may include a femtosecond light source (10), a preamplifier (20), a coupler (91), a first pulse picker (31), a second pulse picker (35), a polarizing beam combiner (95), a main amplifier (50), a polarizing module (60), a compressor (70), and a control module (80).

[0089] The femtosecond light source (10) can generate femtosecond laser light.

[0090] Femtosecond laser light can have a frequency of about 10 MHz to about 1000 MHz.

[0091] The preamplifier (20) can be connected to the femtosecond light source (10).

[0092] The preamplifier (20) can amplify femtosecond laser light.

[0093] The coupler (91) can be connected to the preamplifier (20).

[0094] The coupler (91) can split the femtosecond laser light into a first femtosecond laser light and a second femtosecond laser light.

[0095] The coupler (91) can provide the first femtosecond laser light and the second femtosecond laser light through different polarization axes.

[0096] For example, the coupler (91) can be applied as a 3dB coupler.

[0097] In the following description, we will explain using an example where the first femtosecond laser light is provided through the slow axis of the optical fiber and the second femtosecond laser light is provided through the fast axis of the optical fiber.

[0098] The first pulse speaker (31) and the second pulse speaker (35) can be connected to the coupler (91).

[0099] The first pulse picker (31) can generate the first pulse laser light by modulating the first femtosecond laser light.

[0100] The second pulse picker (35) can generate second pulse laser light by modulating the second femtosecond laser light.

[0101] A polarization beam combiner (PBC) (95) can be connected to a first pulse picker (31) and a second pulse picker (35).

[0102] The polarizing beam combiner (95) can provide the first pulse laser light and the second pulse laser light, which are output from the first pulse picker (31) and the second pulse picker (35), respectively, to the main amplifier (50). At this time, the first pulse laser light and the second pulse laser light will be in a polarization state perpendicular to each other.

[0103] The main amplifier (50) can be connected to a polarizing beam combiner (95).

[0104] The main amplifier (50) can amplify and output either the first pulse laser light or the second pulse laser light.

[0105] The polarization module (60) can be connected to the main amplifier (50).

[0106] The polarization module (60) can transmit either the first pulse laser light or the second pulse laser light output from the main amplifier (50), and reflect and remove the remaining laser light. Here, the laser light transmitted through the polarization module (60) can be compressed by a pulse width compressor (70) and provided to a processing device.

[0107] For example, the polarization module (60) can transmit the laser light selected for processing among the first pulse laser light and the second pulse laser light according to a control signal from the control module (80), and reflect and remove the remaining laser light. That is, the polarization module (60) can transmit the first pulse laser light output from the main amplifier (50) and reflect and remove the second pulse laser light. Alternatively, conversely, the polarization module (60) can transmit the second pulse laser light output from the main amplifier (50) and reflect and remove the first pulse laser light.

[0108] The polarization module (60) can adjust the polarization axis of the laser light selected for processing among the first pulse laser light and the second pulse laser light to transmit it, and reflect and remove the remaining laser light. To this end, the polarization module (60) may include a polarization plate (61) and a polarization beam splitter (65).

[0109] A polarizing plate (HWP: Half Wave Plate) (61) can change the direction of the polarization axis of laser light through an optical fiber.

[0110] For example, the polarization plate (61) can adjust the polarization axis of the laser light selected for processing among the first pulse laser light and the second pulse laser light to align with the axial direction of the pulse width compressor (70).

[0111] The polarizing beam splitter (65) can transmit or reflect laser light that has passed through the polarizing plate (61) through the optical fiber, depending on the polarization state.

[0112] For example, the polarizing beam splitter (65) can transmit laser light that matches the polarization direction of the pulse width compressor (70) as is and provide it to the pulse width compressor (70), and can remove laser light in the other axis direction by reflecting it perpendicular to the angle of incidence. That is, the polarizing beam splitter (65) can transmit the laser light selected for processing among the first pulse laser light and the second pulse laser light as is and provide it to the pulse width compressor (70), and can provide the remaining laser light by reflecting it.

[0113] The pulse width compressor (70) can be connected to the polarization module (60).

[0114] The pulse width compressor (70) can compress the pulse width of the laser light provided by passing through the polarization module (60) and provide it to the processing device.

[0115] For example, the pulse width compressor (70) can compress the pulse width of the laser light selected for processing among the first pulse laser light and the second pulse laser light into a femtosecond or picosecond band and output it to the processing device.

[0116] The control module (80) may include a memory that stores data for an algorithm or a program that reproduces the algorithm for controlling the operation of components within the system, and at least one processor that performs the aforementioned operation using the data stored in the memory. Here, the memory and the processor may each be provided as separate chips. Additionally, the memory and the processor may be provided as a single chip.

[0117] The control module (80) controls the femtosecond light source (10), the preamplifier (20), the first pulse picker (31), the second pulse picker (35), and the polarization module (60), and the main amplifier (50) can control the output of the first pulse laser light and the second pulse laser light.

[0118] For example, the control module (80) may receive a trigger signal (1) from the pre-amplifier (20). The pre-amplifier (20) may increase the pulse width of the femtosecond laser light and amplify it to provide a portion of the signal as the trigger signal (1) to the control module (80). The sink-out signal (3) is a signal corresponding to 1 / n of the femtosecond laser light or the trigger signal (1), where n is a femtosecond laser repetition rate factor that can be set by the user or the control module (80).

[0119] The control module (80) can provide a sink-out signal (3) to the first pulse picker (31) and the second pulse picker (35) to enable the repetition rate to be adjusted according to the trigger signal (1). Here, the first pulse picker (31) and the second pulse picker (35) can generate a first pulse laser light and a second pulse laser light by adjusting the pulse repetition rate of the femtosecond laser light to 1 / n according to the sink-out signal (3).

[0120] The control module (80) can provide a pulse out signal (9) to the first and second pulse pickers (31, 35) to control the on or off of the first pulse laser light output from the polarizing beam combiner (95). For example, the control module (80) can set the on or off of the pulse laser light output according to the processing position in a processing process performed in a processing device, and can generate a pulse out signal (9) according to the setting and provide it to the first and second pulse pickers (31, 35).

[0121] The first and second pulse speakers (31, 35) can output either the first pulse laser light or the second pulse laser light to the main amplifier (50) depending on the on / off state of the pulse out signal (9). For example, when the pulse out signal (9) is on, the first pulse speaker (31) is turned on and the second pulse speaker (35) is turned off to output the first pulse laser light. When the pulse out signal (9) is off, the first pulse speaker (31) is turned off and the second pulse speaker (35) is turned on to output the second pulse laser light. That is, when the pulse out signal (9) is on, the first AOM included in the first pulse speaker (31) is turned on, and the second AOM included in the second pulse speaker (35) is turned off. Additionally, when the pulse out signal (9) is off, the first AOM included in the first pulse speaker (31) is turned off, and the second AOM included in the second pulse speaker (35) is turned on.

[0122] Accordingly, the main amplifier (50) can prevent damage by receiving and amplifying the first pulse laser light when the pulse out signal (9) is on, and receiving and amplifying the second pulse laser light when the pulse out signal (9) is off.

[0123] Meanwhile, the control module (80) can control the polarization module (60) so that the laser light selected for processing among the first pulse laser light and the second pulse laser light amplified by the main amplifier (50) is transmitted.

[0124] The control module (80) can set the laser light to be used for processing among the first pulse laser light and the second pulse laser light. For example, the control module (80) can select the laser light for processing on the system according to the processing process in the processing device. At this time, the remaining laser light among the first pulse laser light and the second pulse laser light that is not selected for processing will be used as a dummy to prevent damage to the main amplifier (50).

[0125] The control module (80) can provide a selection signal to the polarization module (60) to control the polarization axis of the laser light selected for processing among the first pulse laser light and the second pulse laser light so that it can be transmitted.

[0126] For example, when a first pulse laser light having a slow polarization axis is selected as the processing laser light, the polarization module (60) can transmit the first pulse laser light output from the main amplifier (50) as is and reflect and remove the second pulse laser light. Alternatively, when a second pulse laser light having a fast polarization axis is selected as the processing laser light, the polarization module (60) can adjust the polarization axis of the second pulse laser light output from the main amplifier (50) to match the polarization axis of the pulse width compressor (70) and transmit it, and adjust the polarization axis of the first pulse laser light to another axis and reflect it.

[0127] FIG. 4 is a drawing showing a shutter-free femtosecond laser system according to another embodiment of the present disclosure.

[0128] Referring to FIG. 4, a shutter-free femtosecond laser system (102) according to another embodiment of the present disclosure may include a femtosecond light source (10), a coupler (91), a first preamplifier (21), a second preamplifier (25), a first pulse picker (31), a second pulse picker (35), a polarizing beam combiner (95), a main amplifier (50), a polarizing module (60), a compressor (70), and a control module (80).

[0129] The femtosecond light source (10) can generate femtosecond laser light.

[0130] Femtosecond laser light can have a frequency of about 10 MHz to about 1000 MHz.

[0131] The coupler (91) can be connected to a femtosecond light source (10).

[0132] The coupler (91) can split the femtosecond laser light into a first femtosecond laser light and a second femtosecond laser light.

[0133] For example, the coupler (91) can be applied as a 3dB coupler.

[0134] The coupler (91) can provide the first femtosecond laser light and the second femtosecond laser light through different polarization axes.

[0135] In the following description, we will explain using an example where the first femtosecond laser light is provided through the slow axis of the optical fiber and the second femtosecond laser light is provided through the fast axis of the optical fiber.

[0136] The first preamplifier (21) and the second preamplifier (25) can be connected to the coupler (91).

[0137] The first preamplifier (21) can amplify the first femtosecond laser light.

[0138] The second preamplifier (25) can amplify the second femtosecond laser light.

[0139] Meanwhile, the first preamplifier (21) and the second preamplifier (25) can be adjusted so that the first femtosecond laser light and the second femtosecond laser light have different pulse widths.

[0140] To this end, the first preamplifier (21) and the second preamplifier (25) each include different stretchers so that the first femtosecond laser light and the second femtosecond laser light may be adjusted to have different pulse widths. For example, the first preamplifier (21) may be configured to include a first stretcher that stretches the pulse width to 1 ns or more, and the second preamplifier (25) may be configured to include a first stretcher that stretches the pulse width to 1 ns or less.

[0141] Alternatively, the first preamplifier (21) and the second preamplifier (25) may each include a filter having a different band width to adjust the first femtosecond laser light and the second femtosecond laser light to have different pulse widths. For example, the first preamplifier (21) may be configured to include a first filter having a band width equal to or slightly smaller than the band width of the femtosecond light source (10), and the second preamplifier (25) may be configured to include a second filter having a band width smaller than that of the first filter. In such a case, the same stretcher may be applied to the first preamplifier (21) and the second preamplifier (25).

[0142] The first pulse speaker (31) can be connected to the first preamplifier (21).

[0143] The first pulse picker (31) can generate the first pulse laser light by modulating the first femtosecond laser light.

[0144] The second pulse speaker (35) can be connected to the second preamplifier (25).

[0145] The second pulse picker (35) can generate second pulse laser light by modulating the second femtosecond laser light.

[0146] The polarization beam combiner (95) can be connected to the first pulse speaker (31) and the second pulse speaker (35).

[0147] The polarizing beam combiner (95) can provide the first pulse laser light and the second pulse laser light, which are output from the first pulse picker (31) and the second pulse picker (35), respectively, to the main amplifier (50). At this time, the first pulse laser light and the second pulse laser light will be in a polarization state perpendicular to each other.

[0148] The main amplifier (50) can be connected to a polarizing beam combiner (95).

[0149] The main amplifier (50) can amplify and output either the first pulse laser light or the second pulse laser light.

[0150] The polarization module (60) can be connected to the main amplifier (50).

[0151] The polarization module (60) can transmit either the first pulse laser light or the second pulse laser light output from the main amplifier (50), and reflect and remove the remaining laser light. Here, the laser light transmitted through the polarization module (60) can be compressed by a pulse width compressor (70) and provided to a processing device.

[0152] For example, the polarization module (60) can transmit the laser light selected for processing among the first pulse laser light and the second pulse laser light according to a control signal from the control module (80), and reflect and remove the remaining laser light. That is, the polarization module (60) can transmit the first pulse laser light output from the main amplifier (50) and reflect and remove the second pulse laser light. Alternatively, conversely, the polarization module (60) can transmit the second pulse laser light output from the main amplifier (50) and reflect and remove the first pulse laser light.

[0153] The polarization module (60) can adjust the polarization axis of the laser light selected for processing among the first pulse laser light and the second pulse laser light to transmit it, and reflect and remove the remaining laser light. To this end, the polarization module (60) may include a polarization plate (61) and a polarization beam splitter (65).

[0154] The polarization plate (61) can change the direction of the polarization axis of the laser light through the optical fiber.

[0155] For example, the polarization plate (61) can adjust the polarization axis of the laser light selected for processing among the first pulse laser light and the second pulse laser light to align with the axial direction of the pulse width compressor (70).

[0156] The polarizing beam splitter (65) can transmit or reflect laser light through the optical fiber according to its polarization state.

[0157] For example, the polarizing beam splitter (65) can transmit the laser light in the polarization direction of the pulse width compressor (70) as is and provide it to the pulse width compressor (70), and can remove the laser light perpendicular to the polarization direction of the pulse width compressor (70) by reflecting it perpendicular to the angle of incidence. That is, the polarizing beam splitter (65) can transmit the laser light selected for processing among the first pulse laser light and the second pulse laser light as is and provide it to the pulse width compressor (70), and can provide the remaining laser light by reflecting it.

[0158] The pulse width compressor (70) can be connected to the polarization module (60).

[0159] The pulse width compressor (70) can compress the pulse width of the laser light provided by passing through the polarization module (60) and provide it to the processing device.

[0160] For example, the pulse width compressor (70) can compress the pulse width of the laser light selected for processing among the first pulse laser light and the second pulse laser light into a femtosecond or picosecond band and output it to the processing device.

[0161] The control module (80) may include a memory that stores data for an algorithm or a program that reproduces the algorithm for controlling the operation of components within the system, and at least one processor that performs the aforementioned operation using the data stored in the memory. Here, the memory and the processor may each be provided as separate chips. Additionally, the memory and the processor may be provided as a single chip.

[0162] The control module (80) controls the femtosecond light source (10), the first preamplifier (21), the second preamplifier (25), the first pulse speaker (31), the second pulse speaker (35), and the polarization module (60), and the main amplifier (50) can control the output of the first pulse laser light and the second pulse laser light. This will be explained with reference to FIG. 5.

[0163] Figure 5 is a diagram showing an example of signals occurring in the system illustrated in Figure 4.

[0164] For example, the control module (80) may receive a trigger signal (1) from the first preamplifier (21) or the second preamplifier (25). As shown in FIG. 5, the first and second sink-out signals (3, 3') are signals corresponding to 1 / n of the femtosecond laser light or the trigger signal (1), where n is a repetition rate factor of the femtosecond laser light and can be set by the control module (80) or the user. At this time, the first sink-out signal (3) and the second sink-out signal (3') will be set differently according to the repetition rate desired by the user for the first femtosecond laser light and the second femtosecond laser light.

[0165] The control module (80) can be provided to a first pulse speaker (31) and a second pulse speaker (35), respectively, so as to adjust the repetition rate according to the first and second sink-out signals (3, 3'). Here, the first pulse speaker (31) and the second pulse speaker (35) can generate a first pulse laser light and a second pulse laser light by adjusting the pulse repetition rates of the femtosecond laser light differently according to the first and second sink-out signals (3, 3').

[0166] The control module (80) can provide pulse out signals (9, 9') for controlling the on or off of the first pulse laser light output to the first and second pulse pickers (31, 35), respectively. For example, the control module (80) can set the on or off of the pulse laser light output according to the processing position in a processing process performed in a processing device, and can generate pulse out signals (9, 9') according to the setting and provide them to the first and second pulse pickers (31, 35). When the first pulse out signal (9) is on, the first pulse picker (31) is turned on and the second pulse out signal (9') is turned off, and as a result, the second pulse picker (35) is turned off and the first pulse laser light is input to the main amplifier (50). And when the first pulse out signal (9) is off, the second pulse out signal (9') is turned on, and as a result, the first pulse speaker (31) signal is turned off and the second pulse speaker (35) is turned on so that the second pulse laser light is input to the main amplifier (50).

[0167] Here, it is preferable that the pulse out signal (9) be formed to switch on / off between the first sink out signal (3) and the second sink out signal (3') as shown in FIG. 5. Accordingly, either the first pulse laser light and the second pulse laser light having different repetition rates will be output.

[0168] The polarizing beam combiner (95) can output either the first pulse laser light or the second pulse laser light to the main amplifier (50) depending on the on / off state of the pulse out signal (9) by changing the polarization axis. For example, the polarizing beam combiner (95) can output the first pulse laser light when the pulse out signal (9) is on, and output the second pulse laser light when the pulse out signal (9) is off. That is, when the pulse out signal (9) is on, the first AOM included in the first pulse picker (31) is turned on, and the second AOM included in the second pulse picker (35) is turned off. Additionally, when the pulse out signal (9) is off, the first AOM included in the first pulse speaker (31) is turned off, and the second AOM included in the second pulse speaker (35) is turned on.

[0169] Accordingly, the main amplifier (50) can prevent damage by receiving and amplifying the first pulse laser light when the pulse out signal (9) is on, and receiving and amplifying the second pulse laser light when the pulse out signal (9) is off.

[0170] Meanwhile, the control module (80) can control the polarization module (60) so that the laser light selected for processing among the first pulse laser light and the second pulse laser light amplified by the main amplifier (50) is transmitted.

[0171] The control module (80) can set the laser light to be used for processing among the first pulse laser light and the second pulse laser light. For example, the control module (80) can select the laser light for processing on the system according to the processing process in the processing device. At this time, the remaining laser light among the first pulse laser light and the second pulse laser light that is not selected for processing will be used as a dummy to prevent damage to the main amplifier (50).

[0172] The control module (80) can provide a selection signal to the polarization module (60) to control the polarization axis so that the laser light selected for processing among the first pulse laser light and the second pulse laser light can be transmitted to the pulse width compressor (70).

[0173] For example, when a first pulse laser light having a slow polarization axis is selected as the processing laser light, the polarization module (60) can transmit the first pulse laser light output from the main amplifier (50) directly to the compressor (70) and reflect and remove the second pulse laser light. Alternatively, when a second pulse laser light having a fast polarization axis is selected as the processing laser light, the polarization module (60) can adjust the polarization axis of the second pulse laser light output from the main amplifier (50) to match the polarization axis of the pulse width compressor (70) and transmit it, and adjust the polarization axis of the first pulse laser light to another axis and reflect it.

[0174] FIG. 6 is a drawing showing a shutter-free femtosecond laser system according to another embodiment of the present disclosure.

[0175] Referring to FIG. 6, a shutter-free femtosecond laser system (103) according to another embodiment of the present disclosure may include a first femtosecond light source (11), a second femtosecond light source (15), a first preamplifier (21), a second preamplifier (25), a first pulse picker (31), a second pulse picker (35), a polarizing beam combiner (95), a main amplifier (50), a polarizing module (60), a compressor (70), and a control module (80).

[0176] The first femtosecond light source (11) can generate the first femtosecond laser light.

[0177] The second femtosecond light source (15) can generate second femtosecond laser light.

[0178] The first femtosecond laser light and the second femtosecond laser light can be generated as laser light having features including at least one of different repetition rates and pulse widths.

[0179] The first femtosecond laser light and the second femtosecond laser light can be provided through different polarization axes.

[0180] In the following description, we will explain using an example where the first femtosecond laser light is provided through the slow axis of the optical fiber and the second femtosecond laser light is provided through the fast axis of the optical fiber.

[0181] The first preamplifier (21) can be connected to the first femtosecond light source (11).

[0182] The first preamplifier (21) can amplify the first femtosecond laser light.

[0183] The second preamplifier (25) can be connected to the second femtosecond light source (15).

[0184] The second preamplifier (25) can amplify the second femtosecond laser light.

[0185] The first preamplifier (21) and the second preamplifier (25) each include different stretchers so that the first femtosecond laser light and the second femtosecond laser light can be adjusted to have different pulse widths. For example, the first preamplifier (21) may be configured to include a first stretcher that stretches the pulse width to 1 ns or more, and the second preamplifier (25) may be configured to include a first stretcher that stretches the pulse width to 1 ns or less.

[0186] Alternatively, the first preamplifier (21) and the second preamplifier (25) may each include a filter having a different band width to adjust the first femtosecond laser light and the second femtosecond laser light to have different pulse widths. For example, the first preamplifier (21) may be configured to include a first filter having a band width equal to or slightly smaller than the band width of the femtosecond light source (10), and the second preamplifier (25) may be configured to include a second filter having a band width smaller than that of the first filter. In such a case, the same stretcher may be applied to the first preamplifier (21) and the second preamplifier (25).

[0187] The first pulse speaker (31) can be connected to the first preamplifier (21).

[0188] The first pulse picker (31) can generate the first pulse laser light by modulating the first femtosecond laser light.

[0189] The second pulse speaker (35) can be connected to the second preamplifier (25).

[0190] The second pulse picker (35) can generate second pulse laser light by modulating the second femtosecond laser light.

[0191] The polarizing beam combiner (95) can connect the first pulse speaker (31) to the slow axis of the main amplifier (50) and the second pulse speaker (35) to the fast axis of the main amplifier (50).

[0192] The polarizing beam combiner (95) can provide one of the laser light from the first pulsed laser light and the second pulsed laser light output from the first pulsed speaker (31) and the second pulsed speaker (35), respectively, to the main amplifier (50). At this time, the first pulsed laser light and the second pulsed laser light will be in a polarization state perpendicular to each other within the main amplifier (50).

[0193] The main amplifier (50) can be connected to a polarizing beam combiner (95).

[0194] The main amplifier (50) can amplify and output either the first pulse laser light or the second pulse laser light.

[0195] The polarization module (60) can be connected to the main amplifier (50).

[0196] The polarization module (60) can transmit either the first pulse laser light or the second pulse laser light output from the main amplifier (50), and reflect and remove the remaining laser light. Here, the laser light transmitted through the polarization module (60) can be compressed by a pulse width compressor (70) and provided to a processing device.

[0197] For example, the polarization module (60) can transmit the laser light selected for processing among the first pulse laser light and the second pulse laser light according to a control signal from the control module (80), and reflect and remove the remaining laser light. That is, the polarization module (60) can transmit the first pulse laser light output from the main amplifier (50) and reflect and remove the second pulse laser light. Alternatively, conversely, the polarization module (60) can transmit the second pulse laser light output from the main amplifier (50) and reflect and remove the first pulse laser light.

[0198] The polarization module (60) can adjust the polarization axis of the laser light selected for processing among the first pulse laser light and the second pulse laser light to transmit it, and reflect and remove the remaining laser light. To this end, the polarization module (60) may include a polarization plate (61) and a polarization beam splitter (65).

[0199] The polarization plate (61) can change the direction of the polarization axis of the laser light through the optical fiber.

[0200] For example, the polarization plate (61) can adjust the polarization axis of the laser light selected for processing among the first pulse laser light and the second pulse laser light to align with the axial direction of the pulse width compressor (70).

[0201] The polarizing beam splitter (65) can transmit or reflect laser light through the optical fiber according to its polarization state.

[0202] For example, the polarizing beam splitter (65) can transmit laser light that matches the polarization direction of the pulse width compressor (70) as is and provide it to the pulse width compressor (70), and can remove laser light in the other axis direction by reflecting it perpendicular to the angle of incidence. That is, the polarizing beam splitter (65) can transmit the laser light selected for processing among the first pulse laser light and the second pulse laser light as is and provide it to the pulse width compressor (70), and can provide the remaining laser light by reflecting it.

[0203] The pulse width compressor (70) can be connected to the polarization module (60).

[0204] The pulse width compressor (70) can compress the pulse width of the laser light provided by passing through the polarization module (60) and provide it to the processing device.

[0205] For example, the pulse width compressor (70) can compress the pulse width of the laser light selected for processing among the first pulse laser light and the second pulse laser light into a femtosecond or picosecond band and output it to the processing device.

[0206] The control module (80) may include a memory that stores data for an algorithm or a program that reproduces the algorithm for controlling the operation of components within the system, and at least one processor that performs the aforementioned operation using the data stored in the memory. Here, the memory and the processor may each be provided as separate chips. Additionally, the memory and the processor may be provided as a single chip.

[0207] The control module (80) controls the first femtosecond light source (11), the second femtosecond light source (15), the first preamplifier (21), the second preamplifier (25), the first pulse picker (31), the second pulse picker (35), and the polarization module (60), and the main amplifier (50) can control the output of the first pulse laser light and the second pulse laser light.

[0208] For example, the control module (80) may receive a first trigger signal (1) from the first preamplifier (21) and a second trigger signal (1') from the second preamplifier (25). The first and second sink-out signals (3, 3') are signals corresponding to 1 / n of the first and second femtosecond laser light or the first and second trigger signals (1, 1'), where n is a repetition rate factor of the first and second femtosecond laser light and can be set by the user or the control module (80). At this time, the first sink-out signal (3) and the second sink-out signal (3') will be set differently according to the different repetition rates of the first femtosecond laser light and the second femtosecond laser light.

[0209] The control module (80) can provide first and second sink-out signals (3, 3') to the first pulse speaker (31) and the second pulse speaker (35), respectively, to enable adjustment of the repetition rate. Here, the first pulse speaker (31) and the second pulse speaker (35) can generate first pulse laser light and second pulse laser light with different pulse repetition rates of femtosecond laser light according to the first and second sink-out signals (3, 3').

[0210] The control module (80) can provide pulse out signals (9, 9') for controlling the on or off of the first and second pulse laser light outputs to the external gate ports of the first pulse speaker (31) and the second pulse speaker (35). For example, the control module (80) can set the on or off of the pulse laser light output according to the processing position in a processing process performed in a processing device, and can generate pulse out signals (9, 9') according to the setting and provide them to the first and second pulse speakers (31, 35), respectively.

[0211] Here, it is preferable that the pulse out signal (9, 9') be formed to switch on / off between the first sink out signal (3) and the second sink out signal (3'). Accordingly, either the first pulse laser light or the second pulse laser light having different repetition rates will be output.

[0212] The polarizing beam combiner (95) can output either the first pulse laser light or the second pulse laser light to the main amplifier (50) depending on the on / off status of the pulse out signals (9, 9'). For example, when the pulse out signal (9) is on, the polarizing beam combiner (95) can output the first pulse laser light by turning off the pulse out signal (9'), and when the pulse out signal (9) is off, the pulse out signal (9') can be turned on and output the second pulse laser light. That is, when the pulse out signal (9) is on, the pulse out signal (9') is turned off, and as a result, the first AOM included in the first pulse picker (31) is turned on, and the second AOM included in the second pulse picker (35) is turned off. Additionally, when the pulse out signal (9) is off, the first AOM included in the first pulse speaker (31) is turned off, and the second AOM included in the second pulse speaker (35) is turned on.

[0213] Accordingly, the main amplifier (50) can prevent damage by receiving and amplifying the first pulse laser light when the pulse out signal (9) is on, and receiving and amplifying the second pulse laser light when the pulse out signal (9) is off.

[0214] Meanwhile, the control module (80) can control the polarization module (60) so that the laser light selected for processing among the first pulse laser light and the second pulse laser light amplified by the main amplifier (50) is transmitted.

[0215] The control module (80) can set the laser light to be used for processing among the first pulse laser light and the second pulse laser light. For example, the control module (80) can select the laser light for processing on the system according to the processing process in the processing device. At this time, the remaining laser light among the first pulse laser light and the second pulse laser light that is not selected for processing will be used as a dummy to prevent damage to the main amplifier (50).

[0216] The control module (80) can provide a polarization selection signal to the polarization module (60) to control the laser light selected for processing among the first pulse laser light and the second pulse laser light so that it can be transmitted to the compressor (70).

[0217] For example, when a first pulse laser light having a slow polarization axis is selected as the processing laser light, the polarization module (60) can transmit the first pulse laser light output from the main amplifier (50) as is to the compressor (70) and remove the second pulse laser light by reflecting it. Alternatively, when a second pulse laser light having a fast polarization axis is selected as the processing laser light, the polarization module (60) can adjust the polarization axis of the second pulse laser light output from the main amplifier (50) to match the polarization axis of the pulse width compressor (70) and transmit it, and remove the polarization axis of the first pulse laser light by reflecting it.

[0218] FIG. 7 is a drawing showing a shutter-free femtosecond laser system according to another embodiment of the present disclosure.

[0219] Referring to FIG. 7, a shutter-free femtosecond laser system (104) according to another embodiment of the present disclosure may include a first femtosecond light source (11), a second femtosecond light source (15), a first pulse picker (31), a second pulse picker (35), a wavelength multiplexer (97), a main amplifier (50), a pulse width compressor (70), and a control module (80).

[0220] The first femtosecond light source (11) can generate the first femtosecond laser light.

[0221] The second femtosecond light source (15) can generate second femtosecond laser light.

[0222] The first femtosecond laser light and the second femtosecond laser light can be generated as laser light having features including at least one of different repetition rates and pulse widths.

[0223] The first pulse speaker (31) can be connected to the first femtosecond light source (11).

[0224] The first pulse picker (31) can generate the first pulse laser light by modulating the first femtosecond laser light.

[0225] The second pulse picker (35) can be connected to the second femtosecond light source (15).

[0226] The second pulse picker (35) can generate second pulse laser light by modulating the second femtosecond laser light.

[0227] A wavelength division multiplexer (WDM) (97) can be connected to a first pulse speaker (31) and a second pulse speaker (35).

[0228] The wavelength multiplexer (97) can combine the first pulse laser light and the second pulse laser light into different wavelength bands.

[0229] In the following description, the first pulse laser light has a first wavelength band (λ1) and the second pulse laser light has a second wavelength band (λ2) as an example.

[0230] The main amplifier (50) can be connected to a wavelength multiplexer (97).

[0231] The main amplifier (50) can amplify and output either the first pulse laser light or the second pulse laser light.

[0232] The pulse width compressor (70) can be connected to the main amplifier (50).

[0233] The pulse width compressor (70) can compress the pulse width of the laser light selected for processing among the first pulse laser light and the second pulse laser light output from the main amplifier (50) into the femtosecond band and output it to the processing device, and block the output of the remaining pulse laser light. A detailed explanation regarding this will be provided later with reference to FIGS. 8 to 10.

[0234] The control module (80) may include a memory that stores data for an algorithm or a program that reproduces the algorithm for controlling the operation of components within the system, and at least one processor that performs the aforementioned operation using the data stored in the memory. Here, the memory and the processor may each be provided as separate chips. Additionally, the memory and the processor may be provided as a single chip.

[0235] The control module (80) controls the blocking plates of the first femtosecond light source (11), the second femtosecond light source (15), the first pulse picker (31), the second pulse picker (35), and the compressor (70), and the main amplifier (50) can control the output of the first pulse laser light and the second pulse laser light.

[0236] For example, the control module (80) may receive first and second trigger signals (1, 1') from first and second preamplifiers (21, 25) and provide first and second sink-out signals (3, 3') to first and second pulse speakers (31, 35). The first and second sink-out signals (3, 3') are signals corresponding to 1 / n of the trigger signal (1, 1') or femtosecond laser light, where n is a repetition rate factor of the first and second femtosecond laser light and can be set by the user or the control module (80). At this time, the first sink-out signal (3) and the second sink-out signal (3') will be set differently depending on the different characteristics of the first femtosecond laser light and the second femtosecond laser light.

[0237] The control module (80) can provide first and second sink-out signals (3, 3') to the first pulse speaker (31) and the second pulse speaker (35), respectively, to enable adjustment of the repetition rate. Here, the first pulse speaker (31) and the second pulse speaker (35) can generate first pulse laser light and second pulse laser light with different pulse repetition rates of femtosecond laser light according to the first and second sink-out signals (3, 3').

[0238] The control module (80) can provide a pulse out signal (9, 9') for controlling the on or off of the first pulse laser light output to the external gate ports of the first pulse speaker (31) and the second pulse speaker (35). For example, the control module (80) can set the on or off of the pulse laser light output according to the processing position in a processing process performed in a processing device, and can generate a pulse out signal (9, 9') according to the setting and provide it to the first pulse speaker (31) and the second pulse speaker (35).

[0239] Here, it is preferable that the pulse out signal (9, 9') be formed to switch on / off between the first sink out signal (3) and the second sink out signal (3'). Accordingly, either the first pulse laser light or the second pulse laser light having different repetition rates will be output.

[0240] The wavelength multiplexer (97) can output either the first pulse laser light or the second pulse laser light to the main amplifier (50) depending on the on / off state of the pulse out signal (9). For example, when the first pulse out signal (9) is on, the wavelength multiplexer (97) can output the first pulse laser light by turning off the second pulse out signal (9'), and when the first pulse out signal (9) is off, the second pulse out signal (9') can be turned on to output the second pulse laser light. That is, when the pulse out signal (9) is on, the first AOM included in the first pulse picker (31) is turned on, and the second AOM included in the second pulse picker (35) is turned off. Additionally, when the pulse out signal (9) is off, the first AOM included in the first pulse speaker (31) is turned off, and the second AOM included in the second pulse speaker (35) is turned on.

[0241] Accordingly, the main amplifier (50) can prevent damage by receiving and amplifying the first pulse laser light when the pulse out signal (9) is on, and receiving and amplifying the second pulse laser light when the pulse out signal (9) is off.

[0242] Meanwhile, the control module (80) can control the pulse width compressor (70) to output the laser light selected for processing among the first pulse laser light and the second pulse laser light amplified by the main amplifier (50).

[0243] The control module (80) can set the laser light to be used for processing among the first pulse laser light and the second pulse laser light. For example, the control module (80) can select the laser light for processing on the system according to the processing process in the processing device. At this time, the remaining laser light among the first pulse laser light and the second pulse laser light that is not selected for processing will be used as a dummy to prevent damage to the main amplifier (50).

[0244] The control module (80) can provide a selection signal to the pulse width compressor (70) to control that only the wavelength band of the laser light selected for processing among the first pulse laser light and the second pulse laser light is emitted.

[0245] The pulse width compressor (70) can compress and output the laser light selected as the processing laser light according to the selection signal, and block the output of the remaining dummy laser light. This will be explained with reference to FIGS. 8 to 10.

[0246] FIG. 8 is a diagram showing an example of the first wavelength band and the second wavelength band shown in FIG. 7, and FIG. 9 and FIG. 10 are diagrams showing the pulse width compressor shown in FIG. 7.

[0247] Referring to FIG. 8, the first pulse laser light (11') may have a first wavelength band (λ1), and the second pulse laser light (15') may have a second wavelength band (λ2).

[0248] Referring to FIGS. 9 and 10, the pulse width compressor (70) may include an output mirror (71), a first grating (73), a second grating (75), a mirror (77), and a blocking plate (79).

[0249] An output mirror (71) can be provided between the main amplifier (50) and the first grating (73).

[0250] The output mirror (71) may be located below the path of the first pulse laser light (11') and the second pulse laser light (15'). Thus, the first pulse laser light (11') and the second pulse laser light (15') can be transmitted directly to the first grating (73) regardless of the output mirror (71).

[0251] The first grating (73) can be provided between the output mirror (71) and the second grating (75).

[0252] The first grating (73) can diffract the first pulsed laser light (11') and the second pulsed laser light (15'). The first pulsed laser light (11') and the second pulsed laser light (15') can be provided to the second grating (75).

[0253] The second grating (75) may be provided adjacent to the first grating (73).

[0254] The second grating (75) can diffract the first pulse laser light (11') and the second pulse laser light (15') and provide them to the mirror (77).

[0255] The mirror (77) can reflect the first pulse laser light (11') or the second pulse laser light (15') downward. The first pulse laser light (11') or the second pulse laser light (15') reflected downward is sequentially provided to the second grating (75), the first grating (73), and the output mirror (71), and can be reflected by the output mirror (71) and output to the outside.

[0256] A blocking plate (79) can be provided between the second grating (75) and the mirror (77).

[0257] The blocking plate (79) may be positioned to block and remove the first pulse laser light (11') or the second pulse laser light (15') according to a selection signal.

[0258] For example, as illustrated in FIG. 9, when the first pulse laser light (11') is selected as the processing laser light, the blocking plate (79) can block and remove the second pulse laser light (15'). At this time, the first pulse laser light (11') will be supplied to the mirror (77) and output to the outside.

[0259] As illustrated in FIG. 10, when the second pulse laser light (15') is selected as the processing laser light, the blocking plate (79) can block and remove the first pulse laser light (11'). At this time, the second pulse laser light (15') will be supplied to the mirror (77) and output to the outside.

[0260] In this way, the pulse width compressor (70) can use a blocking plate (79) to output a laser light selected as a processing laser light among the first pulse laser light (11') and the second pulse laser light (15') output from the main amplifier (50), and remove the remaining laser light selected as a dummy laser light.

[0261] As described above, the disclosed embodiments have been explained with reference to the attached drawings. Those skilled in the art will understand that the present disclosure may be practiced in forms different from the disclosed embodiments without changing the technical spirit or essential features of the present disclosure. The disclosed embodiments are illustrative and should not be interpreted restrictively.

Claims

A femtosecond light source that generates femtosecond laser light; A pulse picker that generates pulsed laser light by modulating the above femtosecond laser light; An auxiliary light source that generates auxiliary pulsed laser light and provides it through a polarization axis different from that of the pulsed laser light; A control module that generates a pulse out signal to control the output of the pulse laser light and applies it to the pulse picker; and A shutter-free femtosecond laser system comprising: a main amplifier that amplifies the laser light of either the pulsed laser light or the auxiliary pulsed laser light. In paragraph 1, The above auxiliary light source is, A shutter-free femtosecond laser system that provides the auxiliary pulse laser light to the main amplifier to prevent damage to the main amplifier when the output of the pulse laser light is turned off according to the above pulse out signal. In paragraph 1, A shutter-free femtosecond laser system further comprising: a polarization module that adjusts and transmits the polarization axis of the laser light selected for processing among the pulsed laser light and the auxiliary pulsed laser light amplified by the main amplifier, and reflects and removes the remaining laser light. In paragraph 1, A coupler that splits the femtosecond laser light into a first femtosecond laser light and a second femtosecond laser light and provides them through different polarization axes; A first pulse picker that generates a first pulse laser light by modulating the first femtosecond laser light; A second pulse picker that generates a second pulse laser light by modulating the second femtosecond laser light; and It further includes a polarization beam combiner that combines the first pulse laser light and the second pulse laser light; The above control module is, A pulse out signal is generated to output either the first pulse laser light or the second pulse laser light, and applied to the external gate ports of the first pulse speaker and the second pulse speaker. The above main amplifier is, A shutter-free femtosecond laser system that amplifies either the first pulse laser light or the second pulse laser light. In paragraph 4, A shutter-free femtosecond laser system further comprising: a polarization module that adjusts and transmits the polarization axis of the laser light selected for processing among the first pulse laser light and the second pulse laser light amplified by the main amplifier, and reflects and removes the remaining laser light. In paragraph 5, The first pulse picker and the second pulse picker are, A shutter-free femtosecond laser system that adjusts the pulse repetition rates of the first pulse laser light and the second pulse laser light to be the same according to a trigger signal applied from the control module. In paragraph 5, A first preamplifier for adjusting the pulse width of the first femtosecond laser light; and It further includes a second preamplifier that adjusts the pulse width of the second femtosecond laser light differently from the pulse width of the first femtosecond laser light. The first pulse picker and the second pulse picker are, A shutter-free femtosecond laser system in which the first femtosecond laser light and the second femtosecond laser light have different pulse widths and the pulse repetition rate is adjusted differently according to the first sync-out signal and the second sync-out signal, respectively. A first femtosecond light source that generates and provides a first femtosecond laser light; A second femtosecond light source that generates a second femtosecond laser light and provides it through a polarization axis different from the first femtosecond light; A first pulse picker that generates a first pulse laser light by modulating the first femtosecond laser light; A second pulse picker that generates a second pulse laser light by modulating the second femtosecond laser light; A polarizing beam combiner that combines the first pulse laser light and the second pulse laser light; A control module that generates a pulse-out signal to cause either the first pulse laser light or the second pulse laser light to be output from the polarizing beam combiner and applies it to the first pulse picker and the first pulse picker; and A shutter-free femtosecond laser system comprising: a main amplifier that amplifies either the first pulse laser light and the second pulse laser light. A first femtosecond light source that generates a first femtosecond laser light; A second femtosecond light source that generates second femtosecond laser light; A first pulse picker that generates a first pulse laser light by modulating the first femtosecond laser light; A second pulse picker that generates a second pulse laser light by modulating the second femtosecond laser light; A wavelength multiplexer that combines the first pulse laser light and the second pulse laser light into different wavelength bands; A control module that generates a pulse-out signal to cause either the first pulse laser light or the second pulse laser light to be output from the wavelength multiplexer and applies it to the first pulse speaker and the second pulse speaker; and A shutter-free femtosecond laser system comprising: a main amplifier that amplifies either the first pulse laser light and the second pulse laser light. In Paragraph 9, A shutter-free femtosecond laser system further comprising: a pulse width compressor that compresses the laser light selected for processing among the first pulse laser light and the second pulse laser light amplified by the main amplifier and outputs it to a processing device, and blocks the output of the remaining laser light.

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