CN118801200A - A composite pulse laser device and method with adjustable long-short pulse energy ratio - Google Patents

Abstract

The present invention discloses a composite pulse laser device and method with adjustable long-short pulse energy ratio, wherein the laser device comprises a pump module for generating pump pulses; a gain medium for generating gain amplification; a resonant cavity module comprising a total reflector and an output reflector; a Q switch element arranged in the resonant cavity module; and a signal generating unit, wherein the signal generating unit outputs a first signal for controlling the pump module to generate a pump pulse and a second signal for controlling the Q switch element to generate a Q pulse, and a delay time exists between the start time of the pump pulse and the Q pulse so that the laser device outputs a composite pulse laser including the first pulse and the second pulse. The present invention controls the energy proportion of the nanosecond pulse in the entire microsecond pulse by adjusting the delay time between the pump time of the pulse pump module and the start time of the Q switch element, thereby generating a composite pulse laser with adjustable long-short pulse energy ratio and adjusting the length ratio of the laser pulse.

Description

A composite pulse laser device and method with adjustable long-short pulse energy ratio

Technical Field

The present invention relates to the field of solid-state lasers, and more specifically to a composite pulse laser device and method with adjustable long-short pulse energy ratio.

Background Art

Lasers play a vital role in many application fields, such as material processing, optical communications, and medical treatment. However, traditional lasers can only generate single pulses with fixed energy and pulse width, which cannot meet the diverse application requirements.

Different application fields have different requirements for pulse energy and pulse width. For example, in laser processing, an adjustable light source can provide lasers with different energies and pulse widths according to different materials and processing requirements, achieving high-precision, high-efficiency cutting, welding, punching and other processing operations. In laser medical treatment, an adjustable light source can provide lasers with different energies and pulse widths to meet the needs of treating different diseases. Some diseases require higher energy and short pulses to achieve tissue cutting or ablation, while some diseases require lower energy long pulses to achieve mild tissue treatment. In the field of laser communications, an adjustable light source can provide lasers with different energies and pulse widths to meet the needs of high-speed, high-bandwidth data transmission. By adjusting the energy and pulse width of the light source, the modulation of the optical signal can be achieved to improve the transmission rate and capacity of the communication system.

In addition, merging two light sources that generate different pulse energies can achieve the superposition of the pulse energies of the two light sources, further expanding the application range of the light source. However, the device can usually only achieve a fixed pulse energy ratio, lacks adjustability, and cannot achieve real-time adjustment of the pulse energy ratio. In addition, merging two light sources requires complex optical path design and adjustment, which increases the complexity and difficulty of the system.

Summary of the invention

The present invention provides a composite pulse laser device and method with adjustable long-short pulse energy ratio, so as to solve at least one of the problems existing in the prior art.

In order to achieve the above object, the present invention adopts the following technical solutions:

The first aspect of the present invention provides a composite pulse laser device with adjustable long-short pulse energy ratio, the device comprising

A pump module for generating pump pulses;

A gain medium for receiving the pump pulse to generate gain amplification;

A resonant cavity module including a total reflection mirror and an output reflection mirror, used for reflecting and amplifying the output laser;

A Q-switch element disposed in the resonant cavity module; and

A signal generating unit, wherein the signal generating unit outputs a first signal for controlling a pump module to generate a pump pulse and a second signal for controlling a Q switch element to generate a Q pulse, wherein a delay time of a Q pulse start time relative to a pump pulse start time enables the laser device to output a composite pulse laser including a first pulse having a first energy and a second pulse having a second energy, wherein the first energy is greater than the second energy.

Preferably, the pumping module pumps the gain medium in an end-face pumping or side-face pumping manner.

Preferably, the Q switch element is arranged between the gain medium and the output reflector in the resonant cavity module.

Preferably, the delay time of the Q pulse start time relative to the pump pulse start time is adjusted by adjusting the first signal and the second signal output by the signal generating unit to modulate the first energy of the first pulse and the pulse width of the second pulse in the composite pulse laser.

In a second aspect of the present invention, there is provided a method for generating a composite pulse laser with an adjustable long-short pulse energy ratio using the laser device as described above, the method comprising:

The pump module outputs a pump pulse based on the first signal;

The Q switch element modulates the output laser with a Q pulse based on the second signal;

By adjusting the first signal and the second signal, the delay time of the Q pulse start time relative to the pump pulse start time is adjusted so that the laser device outputs a composite pulse laser including a first pulse with a first energy and a second pulse with a second energy, wherein the first energy is greater than the second energy.

Preferably, the pump pulse and the Q pulse have the same repetition frequency.

Preferably, the pulse width of the pump pulse is in the microsecond level or millisecond level, the pulse width of the first pulse is in the nanosecond level, and the pulse width of the second pulse is in the microsecond level or millisecond level.

Preferably, the first energy of the first pulse of the composite pulse laser is increased by extending the delay time.

Preferably, the pulse width of the second pulse is adjusted by adjusting the pulse width of the pump pulse and the delay time.

A third aspect of the present invention provides a design method for generating a composite pulse laser using a laser device, wherein the composite pulse laser device comprises:

A pump module generates a pump pulse in response to a first signal;

A gain medium for receiving the pump pulse to generate gain amplification;

A resonant cavity module including a total reflection mirror and an output reflection mirror, used for reflecting and amplifying the output laser;

A Q switch element is located in the resonant cavity module, between the gain medium and the output reflector, and generates a Q pulse in response to a second signal to modulate the composite pulse laser output by the laser device.

The delay time of the Q pulse start time relative to the pump pulse start time enables the laser device to output a composite pulse laser including a first pulse with a first energy and a second pulse with a second energy.

The design method comprises:

Determining the delay time based on the first energy of the first pulse of the desired composite pulse laser;

Determining the pulse width of the pump pulse based on the pulse width of the second pulse of the desired composite pulse laser and the delay time;

The first signal and the second signal are designed based on the determined pump pulse width and the delay time.

The beneficial effects of the present invention are as follows:

The present invention sets a signal generating unit to output a first signal for controlling a pump module to generate a pump pulse and a second signal for controlling a Q switch element to generate a Q pulse modulated laser output, and controls the delay time of the start time of the Q pulse relative to the start time of the pump pulse, thereby controlling the energy of the nanosecond pulse in a composite pulse laser output including a nanosecond short pulse and a microsecond or millisecond long pulse, and the energy proportion and pulse width proportion of the nanosecond pulse in the entire microsecond composite pulse, thereby providing a composite pulse laser source with adjustable long and short pulse energy and adjustable energy ratio, and realizing the adjustment of the long and short pulse energy ratio and pulse width in the composite pulse laser device.

Compared with the prior art, the present invention adds a Q switch element to the resonant cavity of a conventional laser device and provides a signal generating device for providing a first signal for controlling a pump module and a second signal for controlling the Q switch. By adjusting the pulse width of the pump pulse and the delay time of starting the Q pulse, the energy ratio of different pulses in the composite pulse laser can be flexibly adjusted, and a composite pulse laser including a high-energy nanosecond first pulse and a microsecond or millisecond second pulse is provided, breaking the limitation that traditional lasers only output a single pulse, improving the application flexibility and efficiency of the laser, meeting the diversified demands for pulses in different application scenarios, solving the problem that the combined light source cannot achieve real-time adjustment of the pulse energy, and expanding the application of the laser.

BRIEF DESCRIPTION OF THE DRAWINGS

The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

FIG1 is a schematic structural diagram of a composite pulse laser device with adjustable long-short pulse energy ratio according to the present invention;

FIG. 2 is a schematic diagram showing the composite pulse result with adjustable long-short pulse energy ratio according to the present invention.

DETAILED DESCRIPTION

In order to more clearly illustrate the present invention, the present invention is further described below in conjunction with preferred embodiments and accompanying drawings. Similar components in the accompanying drawings are represented by the same reference numerals. It should be understood by those skilled in the art that the content specifically described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

The first aspect of the present invention provides a composite pulse laser device with adjustable long-short pulse energy ratio, as shown in FIG1 , the device comprises a pump module 11, a gain medium 12, a resonant cavity module 13 and a Q switch element 2, wherein the pump module 11 receives a first signal 10 emitted by an external signal generating module 1, generates a pump pulse, and is used to provide pump energy for the gain medium 12. The gain medium 12 is any solid laser medium that can generate laser gain amplification, and is used to generate gain and amplify laser light; the resonant cavity module 13 comprises a total reflection mirror 131 and an output reflection mirror 132, and the laser light is reflected and amplified between the total reflection mirror 131 and the output reflection mirror 132 and then outputted through the output reflection mirror 132. The Q switch element 2 receives a second signal 20 emitted by the external signal generating module 1, and is used to generate a Q pulse; the delay time of the Q pulse relative to the pump pulse can enable the laser device to output a high-energy nanometer-level short pulse. In the composite pulse laser output by the laser device of the present invention, the energy of the nanometer-level short pulse is determined by the delay time; the pulse width of the microsecond or millisecond-level long pulse is determined by the pulse width of the pump pulse and the delay time. It should be understood that the energy of the pump pulse is one of the factors affecting the energy of the composite pulse laser. Its influence on the energy of the long pulse and the adjustment method are conventional technical means in the field and will not be repeated here. The present invention can adjust the energy of the short pulse by adjusting the delay time to adjust the energy ratio of the long pulse and the short pulse, thereby achieving real-time adjustment of the energy of the composite pulse laser.

According to Figure 1, the external signal generating module 1 is in a dual-channel mode, and the first channel and the second channel are controlled by a high-level signal to respectively send out a first signal 10 and a second signal 20, ensuring that the initial phases of the first signal 10 and the second signal 20 are consistent. The first signal 10 is a pump signal for controlling the pump module 11, and the second signal 20 is a start signal for controlling the Q switch element. The Q switch element 2 is located inside the resonant cavity module 13, specifically between the gain medium 12 and the output reflector 132, and can be controlled by the same external signal generating unit as the pump module 11. The Q switch element 2 can be a pulse modulation device such as an acousto-optic Q switch element or an electro-optic Q switch element. The present embodiment uses an acousto-optic Q switch element.

The pump module 11 is a pulse pump source. The pumping mode that the pump module 11 can adopt for the gain medium 12 is end pumping or side pumping. The pulse width of the pump pulse output by the pump module 11 can be in the microsecond level or millisecond level. In this embodiment, the long pulse is a microsecond pulse, and the short pulse is a nanosecond pulse. The pump pulse width and repetition frequency of the pump module 11 are tunable, that is, they can be set to different values to achieve customized output. The first signal 10 and the second signal 20 make the repetition frequency of the pump pulse of the pump module 11 the same as the repetition frequency of the Q pulse to ensure the generation of stable and reliable long pulses and short pulses. The pulse width and energy proportion of the laser pulse can be controlled by adjusting the pulse width of the pump pulse of the pump module 11. For example, by adjusting the delay time of the Q pulse relative to the pump pulse, the energy of the short pulse in the composite pulse laser can be adjusted; by adjusting the pulse width and delay time of the pump pulse, the pulse width of the long pulse in the composite pulse can be adjusted; by adjusting the energy of the pump pulse, the energy of the long pulse in the composite pulse can be adjusted. Therefore, the present invention can flexibly adjust the pulse width and energy ratio of different pulses in the output composite pulse laser by setting the first signal and the second signal, breaking the limitation that the traditional laser only outputs a single pulse. The composite pulse laser device of the present invention can meet the diversified needs for pulses in different application scenarios, solve the problem that the combined light source cannot achieve real-time adjustable pulse energy, expand the application of lasers, and improve the application flexibility and efficiency of lasers.

Specifically, the acousto-optic Q-switch element actively controls the quality factor value (Q factor) of the resonant cavity module 13, that is, generates high-intensity pulsed light by adjusting the size of the internal loss of the resonant cavity. If there is no ultrasonic wave in the acousto-optic Q-switch element, the laser beam can freely pass through the acousto-optic Q-switch element, the quality factor of the resonant cavity module 13 is very high, the internal loss of the resonant cavity is small, and laser oscillation is easy to generate; if there is ultrasonic wave in the acousto-optic Q-switch element, the medium density of the acousto-optic Q-switch element changes periodically, resulting in a periodic change in its refractive index, which deflects the laser beam and diffracts the light wave. The quality factor of the resonant cavity module 13 is very low, and the loss in the cavity is large, so that the number of upper energy level particles accumulates rapidly; if the number of upper energy level particles accumulates to a saturation value, the acousto-optic Q-switch element receives the second signal 20 sent by the external signal generating module, and the acousto-optic Q-switch element is quickly turned on. At this time, the resonant cavity module 13 is in a high quality factor value state, the loss is greatly reduced, the oscillation threshold is suddenly reduced, and the laser oscillation is quickly established. In a very short time, the accumulated upper energy level particle number is consumed and converted into light energy in the cavity, which is released from the output end of the resonant cavity module 13 in the form of a single pulse, and a giant pulse with a very high peak power is obtained, that is, a high-energy short pulse is output. After the short pulse is formed, the laser device operates as a conventional pulse laser device to output pulses.

The pump module 11 receives the first signal 10 to give the gain medium 12 a certain amount of pump light energy, so that the number of upper energy level particles begins to accumulate, but because the resonant cavity module 13 is in a high loss state at this time, the laser is not easy to oscillate, so that the number of upper energy level particles continues to accumulate rapidly. At this time, the acousto-optic Q switch element is controlled to turn on by the second signal 20. The laser resonant cavity module 13 is in a low loss state at the moment of turning on the acousto-optic Q switch element, and the oscillation threshold is greatly reduced. The number of upper energy level particles in the saturated state is instantly released to form a high-energy short pulse. By adjusting the delay time between the first signal 10 received by the pulse pump module 11 in the composite pulse laser device and the second signal 20 received by the acousto-optic Q switch element, that is, controlling the delay time T, the energy proportion of the nanosecond pulse in the entire microsecond pulse is adjusted. By controlling the different delay times T, the cumulative amount of the number of particles at the upper energy level is controlled, thereby controlling the output size of the high-energy giant pulse: the delay time T between the first signal 10 and the second signal 20 is controlled to be longer, so that the cumulative amount of the number of particles at the energy level is large, forming a short pulse with high energy; the delay time T between the first signal 10 and the second signal 20 is controlled to be shorter, so that the cumulative amount of the number of particles at the energy level is small, forming a short pulse with relatively small energy, thereby adjusting the energy ratio of long and short pulses.

By changing the delay time T, the energy of the short pulse is controlled, the size of the short pulse and the long pulse and the time distribution between them are controlled, and the energy ratio between the long and short pulses is indirectly adjusted. In this embodiment, the energy ratio of the long and short pulses can also be adjusted by adjusting the pulse width of the pump module 11, specifically: based on the unchanged delay time between the first signal 10 and the second signal 20, the pulse width of the pump module 11 is adjusted to change the pulse width of the long pulse, control the energy of the long pulse, and achieve the energy ratio of the long pulse and the short pulse. Specifically: the narrower the pulse width of the pump pulse, the shorter the duration of the stimulated emission of the laser medium, which may result in lower energy of the output long pulse, and the pulse width will also be affected. On the contrary, the wider the pulse width of the pump pulse, generally speaking, a higher energy output long pulse will be generated, but it may also cause the time width of the output pulse to increase accordingly. In this way, the energy of the long pulse and the energy ratio between the long and short pulses are changed.

FIG2 is a schematic diagram of the result of adjusting the energy ratio of long and short pulses in this embodiment, wherein the three curves from top to bottom represent the pump pulse, Q pulse and laser pulse with a period of P and a pulse width of W, respectively. E1 represents the energy of the short pulse in the laser pulse, and E2 represents the energy of the long pulse in the laser pulse. The short pulse is, for example, a nanosecond pulse with a pulse width of W1; the long pulse is, for example, a microsecond pulse with a pulse width of W2. T is the delay time between the pumping time of the pump module 11 and the opening time of the Q switch element 2. The Q pulse has the same period P as the pump pulse, that is, the same repetition frequency. A Q switch element is added to a conventional laser device. Before the Q switch element is turned on, the delay time between the pumping time of the pump module and the opening time of the Q switch element is used to accumulate the number of upper energy level particles, generating a nanosecond short pulse of huge energy. After that, the Q switch element is in the on state, and the loss in the cavity is small. The number of particles is no longer rapidly accumulated to form a short pulse, but a laser oscillation outputs a long pulse. The sum of the pulse widths of the long pulse and the short pulse in the output composite laser pulse (W1+W2) is less than the pulse width W of the pump pulse. After the pump pulse stops pumping, the Q switch element is turned off and waits for the next cycle to arrive.

The second aspect of the present invention provides a method for adjusting the energy ratio of long and short pulses, wherein the method controls the intensity and duration of the pump light, i.e., the pulse width, by receiving a first signal sent by an external signal generating module through a pump module;

The second signal sent by the external signal generating module is received by the Q switch element to control the output time and pulse energy of the short pulse in the resonant cavity;

The current or pulse width of the pump module is adjusted to adjust the light intensity and duration of the pump light. The duration and energy of the long pulse of the composite pulse laser are controlled by adjusting the pulse width of the pump module. The repetition frequency of the pump module is adjusted to be the same as the repetition frequency of the Q switch element, so as to control the periods of the pump pulse and the Q pulse to be the same.

By adjusting the delay time between the first signal and the second signal, the energy of the short pulse is controlled, thereby adjusting the energy ratio of the long pulse to the short pulse.

In a specific implementation, the pump module 11 receives the first signal 10 sent by the external signal generating module to control the pump time of the pump module 11, and the Q switch element 2 receives the second signal 20 sent by the external signal generating module to control the start time of the Q switch element 2; by adjusting the delay time between the first signal 10 and the second signal 20, the cumulative amount of the upper energy level particle number is controlled, and finally the energy of the output short pulse is controlled to achieve the adjustment of the energy of the long pulse and the short pulse. At the moment of turning on the Q switch element, the accumulated number of particles is released to generate a high-energy short pulse. Among them, the delay time is proportional to the cumulative amount of the upper energy level particle number, that is, the longer the control delay time is, the greater the cumulative amount of the upper energy level particle number is. By controlling the delay time, the size of the energy of the first short pulse is controlled, and the proportion of the energy of the subsequent long and short pulses is adjusted. Specifically: by adjusting the delay time T between the pump module 11 and the Q switch element 2, the cumulative amount of the upper energy level particle number in the laser device can be controlled. If the delay time is long, the cumulative amount of the upper energy level particle number is controlled to be large, and the energy of the short pulse released at the moment of turning on the Q switch element 2 is large. By changing the delay time, controlling the energy of the short pulse, and controlling the size of the short pulse and the subsequent long pulse, the energy ratio between the long pulse and the short pulse can be adjusted. The pulse width of the pump pulse can also be adjusted to change the energy of the long pulse, thereby indirectly adjusting the energy ratio between the long pulse and the short pulse.

The third invention of the present invention provides a design method for generating a composite pulse laser using a laser device, wherein the composite pulse laser device includes a pump module that generates a pump pulse in response to a first signal, a gain medium that receives the pump pulse to generate gain amplification, a resonant cavity module that includes a total reflection mirror and an output reflection mirror for reflecting and amplifying the output laser, and a Q switch element that is located in the resonant cavity module, between the gain medium and the output reflection mirror, and generates a Q pulse in response to a second signal to modulate the composite pulse laser output by the laser device, wherein the delay time of the Q pulse start time relative to the pump pulse start time enables the laser device to output a composite pulse laser including a first pulse with a first energy and a second pulse with a second energy.

The design method of the present invention comprises the following steps:

Determining the delay time based on the first energy of the first pulse of the desired composite pulse laser;

Determining the pulse width of the pump pulse based on the pulse width of the second pulse of the desired composite pulse laser and the delay time;

The first signal and the second signal are designed based on the determined pump pulse width and the delay time.

According to the design method of the composite pulse laser of the present invention, the pulse width of the pump pulse and the delay time between the pump pulse and the Q pulse can be adjusted according to the diversified demands for pulses in different application scenarios by designing the first signal input to the pump module and the second signal input to the Q switch element, and composite pulse lasers including different peak energies and different pulse widths can be output in real time, thereby realizing a laser device with application flexibility.

In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

It should also be noted that, in the description of the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims (10)

1. A composite pulse laser device with adjustable energy ratio of long pulse and short pulse is characterized in that the device comprises

A pump module for generating pump pulses;

receiving the pump pulse to generate a gain medium for gain amplification;

the resonant cavity module comprises a total reflecting mirror and an output reflecting mirror and is used for reflecting and amplifying output laser;

a Q-switch element disposed within the resonant cavity module; and

The signal generation unit outputs a first signal for controlling the pumping module to generate pumping pulse and a second signal for controlling the Q switch element to generate Q pulse, and the delay time of the Q pulse starting time relative to the pumping pulse starting time enables the laser device to output composite pulse laser comprising first pulse with first energy and first width and second pulse with second energy and second width, and the first energy is larger than the second energy.

2. The laser device of claim 1, wherein the pumping mode of the gain medium by the pumping module is end-pumping or side-pumping.

3. The laser device of claim 1, wherein the Q-switch element is disposed in the resonator module between the gain medium and the output mirror.

4. The laser device according to claim 1, wherein the pulse width of the first pulse and the second pulse in the composite pulse laser is modulated by adjusting the delay time of the Q-pulse start time with respect to the pump pulse start time by adjusting the first signal and the second signal output from the signal generating unit.

5. A method of generating a composite pulse laser with an adjustable long-to-short pulse energy ratio using the laser apparatus of claim 1, the method comprising

The pumping module outputs pumping pulses based on the first signal;

the Q-switching element modulates the output laser light in Q pulses based on the second signal;

the delay time of the Q pulse starting time relative to the pump pulse starting time is adjusted by adjusting the first signal and the second signal, so that the laser device outputs composite pulse laser comprising a first pulse with first energy and a second pulse with second energy, and the first energy is larger than the second energy.

6. The method of claim 5, wherein the pump pulse and the Q pulse have the same repetition frequency.

7. The method of claim 5, wherein the pulse width of the pump pulse is on the order of microseconds or milliseconds, the pulse width of the first pulse is on the order of nanoseconds, and the pulse width of the second pulse is on the order of microseconds or milliseconds.

8. The method of claim 5, wherein the first energy of the first pulse of the composite pulse laser is increased by extending the delay time.

9. The method of claim 5, wherein the pulse width of the second pulse is adjusted by adjusting the pulse width of the pump pulse and the delay time.

10. A design method for generating composite pulse laser by using a laser device is characterized in that,

The composite pulse laser device comprises

A pumping module generating a pumping pulse in response to the first signal;

receiving the pump pulse to generate a gain medium for gain amplification;

the resonant cavity module comprises a total reflecting mirror and an output reflecting mirror and is used for reflecting and amplifying output laser;

A Q-switch element disposed in the resonator module between the gain medium and the output mirror, for generating a Q-pulse in response to a second signal to modulate the composite pulse laser output by the laser device,

Wherein the delay time of the Q pulse starting time relative to the pump pulse starting time enables the laser device to output composite pulse laser comprising a first pulse with first energy and a second pulse with second energy,

The design method comprises the following steps:

Determining the delay time based on a first energy of a first pulse of the desired composite pulse laser;

determining a pulse width of the pump pulse based on the pulse width of the second pulse of the desired composite pulse laser and the delay time;

the first signal and the second signal are designed based on the determined pump pulse width and the delay time.