Method and laser system for generating output laser pulses with power-efficient and temperature-dependent optical components and associated computer program product

Abstract

A method for generating output laser pulses (3) from input laser pulses (2) each having a previously known pulse energy and pulse interval, the input laser pulses (2) successively in time passing through a power-temperature-dependent optical component (1), in the process heating up the optical component (1), and being emitted as output laser pulses (3) from the optical component (1), in which method, according to the invention, the current temperature (T) or the current temperature difference, or the current temperature-dependent parameter, of the optical component (1) is calculated on the basis of all previous input laser pulses or output laser pulses (2, 3) that have contributed to the current heating of the optical component (1), and the power of the current input laser pulse (2) is set on the basis of the calculated current temperature (T), the calculated current temperature difference, or the calculated current parameter, such that the pulse energy of the associated output laser pulse (3) deviates by less than 5% from a predetermined pulse energy. In a laser system (4), a control unit (7) is programmed to implement the method accordingly.

Description

Technical Field

[0001] The present invention relates to a method for generating an output laser pulse from input laser pulses having previously known pulse energies and pulse intervals, the input laser pulses passing sequentially through a power-efficiency-temperature-dependent optical element, thereby heating the optical element, and exiting the optical element as an output laser pulse. The invention also relates to a laser system suitable for performing this method and an associated control program product. Background Technology

[0002] In laser systems where power efficiency is temperature-dependent (e.g., laser systems with frequency conversion, thermal lenses, etc.), the laser pulse power may be temperature-dependent, and due to the temperature-determined nature of these characteristics, fluctuations in peak pulse power, pulse energy, pulse duration, or pulse quality may occur at very high power levels.

[0003] To achieve constant efficiency during frequency conversion, US 6,697,390 B2 specifies that the temperature at the nonlinear conversion crystal is measured, and constant efficiency is achieved by heating / cooling the conversion crystal to maintain it at a constant temperature level. Furthermore, the pump power is tuned to compensate for degradation in the nonlinear crystal.

[0004] Frequency-converted (especially pulsed) laser radiation triggered by arbitrary external single pulses (so-called POD (pulsed-on-demand) laser pulses) introduces non-constant, unpredictable thermal loads and single-pulse energy fluctuations in laser systems (e.g., due to phase mismatch or beam size changes). These fluctuations cannot be adequately corrected by tuning over timescales associated with typical processing to achieve inter-pulse stability typically less than 1% to 2% of the root mean square.

[0005] Among the output parameters (conversion efficiency of the optical frequency to be generated and laser pulse energy (phase matching)), laser systems with nonlinear frequency conversion are particularly sensitive to beam size and beam quality, as well as the phase matching of the fundamental laser radiation on the input side. If the laser system deviates from its thermal equilibrium (load change), these parameters will change non-instantaneously, as is the case with arbitrary external single-pulse triggering. POD laser pulses inherently require very rapid dynamic load changes, which are often unpredictable by the laser manufacturer. This can be problematic for narrow-gauge inter-pulse stability (e.g., 1% to 2% RMS), especially because regulation is therefore too slow in general. In the case of laser systems with requested pulse intervals in the microsecond range, these fluctuations can no longer be compensated for by temperature regulation, as thermal compensation is typically only ensured in the millisecond / second range.

[0006] Known short-pulse laser systems with pulse durations in the femtosecond or picosecond range have clock-rate-dependent laser pulse energies at constant pump power and typically operate at a constant frequency. In POD operation, users desire to operate the laser pulse using freely selectable triggering and a constant, configurable pulse energy. Previous POD schemes focused on constant pulse energy. In the case of nonlinear systems, the same nonlinearity must also be ensured to obtain consistent temporal pulse characteristics, such as pulse duration and pulse width. This is particularly important for subsequent frequency conversion or other nonlinear processes (e.g., glass cutting).

[0007] When the processing procedure is known to remain constant (average power does not change much), the POD parameters can be set to a specific operating point, and a minimum energy deviation can be set. The automatic parameterization routines used to date for optimizing POD parameters are slow because these parameters are determined using stable thermal equilibrium at a fixed repetition rate (plus sacrificial laser pulses). Summary of the Invention

[0008] In this context, the present invention is based on the objective of generating output laser pulses with low jitter (i.e., pulse energy deviation of less than 5%, preferably less than 2%, and particularly with the same pulse energy) regardless of the temperature-dependent power efficiency of the optical components, in the context of the method mentioned in the introduction, and also describes an associated laser system.

[0009] In the context of the method mentioned in the introduction, according to the present invention, this objective is achieved by calculating the current temperature or current temperature difference of the optical element, or a temperature-related current parameter, based on all previous input or output laser pulses that contribute to the current heating of the optical element; and setting the power of the current input laser pulse based on the calculated current temperature, calculated current temperature difference, or calculated current parameter, such that the deviation of the pulse energy of the associated output laser pulse from a predetermined pulse energy is less than 5%, preferably less than 2%, and particularly equal to the predetermined pulse energy. Preferably, the optical element amplifies the selected input laser pulse or performs frequency conversion on it.

[0010] The temperature difference may be related to the "cold" equilibrium state (thermal equilibrium) of the optical components. For example, temperature-related parameters can be temperature-related control parameters.

[0011] According to the present invention, the temperature or temperature difference of an optical component, or temperature-related parameters, can be calculated or simulated almost in real time using a computational model, from which a correction for the laser pulse energy can be derived and modulated onto the current input laser pulse. The calculated temperature, temperature difference, and parameters are not actual temperatures, temperature differences, or measured variables of the optical component, but rather abstract variables. In this case, the computational model incorporates each previous laser pulse that has passed through the optical component and contributes to its current heating. The power of the previous input laser pulse is then adjusted to obtain the desired pulse energy after passing through the optical component. For example, the power of the current input laser pulse can be set based on the calculated deviation between the current temperature and the predetermined (full load) operating temperature of the optical component.

[0012] The method according to the invention provides, in particular, the following advantages:

[0013] – Although different operating points exhibit different thermal loads, any dynamic triggering procedure can still be initiated.

[0014] – A pause time (typically a few seconds) to stabilize the laser can be omitted before the process begins.

[0015] –For example, more complex thermal performance in the case of multiple optical components (each with power efficiency dependent on temperature) can be simulated, for example, by a model with multiple independent temperatures.

[0016] Preferably, before passing through the optical components, the power of the current input laser pulse is set or modified by adjusting the pulse shape, particularly by adjusting its amplitude and / or at least one of its two pulse edges. Alternatively or additionally, the power of the current input laser pulse can be set based on a calculated current temperature, a calculated current temperature difference, or a calculated current parameter as early as when the current input laser pulse is generated.

[0017] In cases where the input laser pulse is amplified in front of the optical component and at least one input laser pulse is used as an additional pulse (so-called sacrificial laser pulse), it is preferable to couple this sacrificial laser pulse out again from the path of the amplified input laser pulse in front of the optical component.

[0018] Instead of a single input laser pulse, multiple adjacent input laser pulses can also pass through the optical components as a laser burst and exit from the optical components as an output laser burst.

[0019] In one variation, the timing of the input laser pulse causes the output laser pulse to arrive at the output as a POD laser pulse at a separately requested time. If needed, at least one input laser pulse is used as an auxiliary pulse (a so-called sacrificial laser pulse), which is then coupled back to the output from the path of the amplified input laser pulse.

[0020] Preferably, each laser pulse is selected from a sequence of (seed) laser pulses having known pulse energies, particularly those having the same pulse energy, said laser pulses preferably repeating at a fixed frequency and provided as input laser pulses having known pulse energies and pulse intervals. Alternatively, it is already possible to generate laser pulses having known pulse energies and pulse intervals and provide them as input laser pulses.

[0021] In another aspect, the present invention also relates to a laser system for generating an output laser pulse from input laser pulses having previously known pulse energies and pulse intervals, the laser system comprising:

[0022] – A pulse source, which provides input laser pulses with previously known pulse energies and pulse intervals.

[0023] – An optical component whose power efficiency is temperature-dependent. An input laser pulse passes through this optical component, and the component heats up simultaneously. The input laser pulse is then emitted as an output laser pulse from the optical component.

[0024] – A power setting device, used to set the corresponding pulse power of the input laser pulse, and

[0025] – A control unit (e.g., an FPGA (Field Programmable Gate Array) or a microcontroller) is programmed to calculate the current temperature or current temperature difference of the optical element, or a temperature-related current parameter, based on all previous input laser pulses that contribute to the current heating of the optical element, and to manipulate the power setting device for the current input laser pulse based on the calculated current temperature, calculated current temperature difference, or calculated current parameter, such that the deviation of the pulse energy of the associated output laser pulse from a predetermined pulse energy is less than 5%, preferably less than 2%, and in particular equal to the predetermined pulse energy.

[0026] Optical components can be, for example, optical amplifiers for amplifying input laser pulses or (non-linear) conversion crystals for converting the frequency of input laser pulses.

[0027] The power setting device is preferably configured as an acousto-optic modulator (AOM) or electro-optic modulator (EOM) for adjusting the pulse shape of the current input laser pulse. The modulator's on-time and duration can be controlled by a control unit, allowing the power of the current input laser pulse to be set as needed by adjusting its pulse shape, particularly by adjusting its amplitude and / or at least one of its two pulse edges. Alternatively, the power setting device can also be formed by power adjustment of the laser pulse generated by a pulse source as the input laser pulse, in order to set the power of the current input laser pulse as required.

[0028] An optical amplifier for amplifying the input laser pulse can be positioned in front of the optical components. In cases where the sacrificial laser pulse is also amplified in the amplifier, advantageously, a coupling output unit (e.g., AOM or EOM), controlled by a control unit, for coupling the amplified sacrificial laser pulse from the path of the amplified input laser pulse, is positioned behind the amplifier and, particularly, in front of the optical components.

[0029] In one preferred embodiment, the pulse source includes: a laser pulse generator for generating (seed) laser pulses having known pulse energies, particularly having the same pulse energy, said laser pulses preferably repeating at a fixed frequency; and a selection unit for selecting some of these laser pulses as input laser pulses at previously known pulse times, said selection unit being controlled by a control unit. In another preferred embodiment, the pulse source includes a laser pulse generator controlled by a control unit to generate input laser pulses whose pulse energies and pulse times are predefined by the control unit. In this case, the seed laser pulse generator can be implemented as follows:

[0030] - Fiber optic oscillators and amplifiers (fiber optic or other media) with pulse durations in the range of femtoseconds to nanoseconds;

[0031] - Laser diodes and amplifiers (fiber optics or other media) with pulse durations in the nanosecond range.

[0032] Finally, the present invention also relates to a control program product comprising a code medium adapted to execute all steps of the above-described method when the program is run on the control unit of the laser system described above.

[0033] Further advantages and advantageous configurations of the subject matter of this invention will be apparent from the description, claims, and drawings. Similarly, the foregoing features and features to be presented may be used independently or in any desired combination as a plurality. The embodiments shown and described are not to be construed as exhaustive, but rather have exemplary characteristics for summarizing the invention. Attached Figure Description

[0034] In the attached diagram:

[0035] Figure 1 The diagram schematically illustrates the power efficiency and temperature-dependent optical components through which the input laser pulse passes.

[0036] Figure 2a , Figure 2b The illustration schematically shows an optical component with power efficiency dependent on temperature through which an input laser pulse passes, as calculated according to the present invention, under the condition of periodically repeating input laser pulses with the same pulse energy. Figure 2a And in the case of non-periodic input laser pulses with different pulse energies ( Figure 2b The process of temperature change over time;

[0037] Figure 3 A first laser system according to the present invention is schematically shown, the first laser system comprising: Figure 1 The optical components shown;

[0038] Figure 4 It shows Figure 3 The laser system shown includes an additional optical amplifier; and

[0039] Figure 5 A second laser system according to the present invention is schematically shown, the second laser system comprising: Figure 1 The optical components shown. Detailed Implementation

[0040] Figure 1 The optical element 1 shown is used to optically influence multiple (two for example only) input laser pulses 2, which pass through the optical element 1 sequentially in time and are emitted from the optical element 1 as output laser pulses 3.

[0041] The power efficiency of optical component 1 is temperature-dependent and heats up as it passes through the input laser pulse 2, such that the power efficiency of optical component 1 varies over time depending on the input laser pulse 2 that has passed through. Optical component 1 can be, for example, a nonlinear conversion crystal for converting the frequency of the input laser pulse 2 or an optical amplifier for amplifying the input laser pulse 2. The (abstract) current temperature T of optical component 1 can be calculated based on all previous input laser pulses 2 that have passed through optical component 1 and thus contributed to the current heating of optical component 1.

[0042] Figure 2a , Figure 2b The diagram schematically illustrates the power efficiency and temperature-dependent properties of the input laser pulse 2 passing through the optical component 1 under the condition of periodically repeating input laser pulses 2 with the same pulse energy. Figure 2a ) and in the case of input laser pulses 2 with different pulse energies that are non-periodic or only partially periodic. Figure 2b The calculation shows the time-varying process of the current temperature T. The periodically repeating input laser pulse 2 causes the optical component 1 to heat up from its initial temperature T0 in a cold (off) state to a essentially constant operating temperature T. B In contrast, non-periodic repetitive input laser pulses 2 with different time intervals and / or different pulse energies cause the initial temperature T0 to differ from the operating temperature T. B Large temperature fluctuations between these temperatures cause considerable fluctuations in the power efficiency of optical component 1.

[0043] Figure 3 The laser system 4 shown includes the following components:

[0044] – Pulse source 5, which is used to provide input laser pulses 2, each having a previously known pulse energy.

[0045] – An optical element 1, whose power efficiency is temperature-dependent, receives an input laser pulse 2 which passes through it, causing the element to heat up. The input laser pulse 2 is then emitted as an output laser pulse 3 from the optical element 1.

[0046] - Power setting device 6, which is arranged between pulse source 5 and optical component 1, for example in the form of AOM (acousto-optic modulator) or EOM (electro-optic modulator), is used to set or reduce the corresponding pulse power of input laser pulse 2, and

[0047] – Control unit 7, which controls the pulse source 5 for providing the input laser pulse 2 and the power setting device 6 for setting the corresponding pulse power.

[0048] Optical component 1 may be, for example, a nonlinear conversion crystal for converting the frequency of the input laser pulse 2 or an optical amplifier for amplifying the input laser pulse 2. Power setting device 6 reduces the pulse power of the input laser pulse 2 by adjusting the amplitude and / or one or two pulse edges. The pulse portion removed by adjustment is directed to an absorber (not shown).

[0049] An input laser pulse 2 with known pulse energy is triggered by the control unit 7 in a timed manner; that is, the control unit 7 knows both the pulse energy and the time of all triggered input laser pulses 2. The control unit 7 calculates the (abstract) current temperature T of the optical element 1, or the (abstract) current temperature difference ΔT as described below, based on all previous input laser pulses 2 that have passed through the optical element 1 and thus contributed to the current heating of the optical element 1. Based on the calculated current temperature T of the optical element 1, the control unit 7 controls the power setting device 6 for the current input laser pulse 2 triggered by the control unit 7 in a timed manner, such that after passing through the optical element 1, the pulse energy of the associated output laser pulse 3 deviates from the predetermined pulse energy by less than 5%, preferably less than 2%, and in particular equal to the predetermined pulse energy. Upon user request 8, the control unit 7 triggers or provides the input laser pulse 2 such that the associated output laser pulse 3 arrives at the output terminal 9 at the individually requested POD (Pulse on Demand) time.

[0050] The described method works only by controlling the laser source 5 and the power setting device 6 with time via the control unit 7, that is, they are not regulated.

[0051] like Figure 3 As shown, the pulse source 5 may include: a laser pulse generator 10 for generating (seed) laser pulses 11; and a selection unit (pulse pickup) 12, controlled by the control unit 7, for selecting some of the seed laser pulses 11 as input laser pulses 2, for example in the form of AOM or EOM. The laser pulse generator 10 repeats the seed laser pulses 11 at an input frequency f0, which is fixedly set and particularly in the MHz range, for example, between 10MHz and 200MHz. The selected seed laser pulses 11 are allowed to pass as input laser pulses 2 without being deflected by the pulse pickup 12, while the unselected seed laser pulses 11 are coupled out by the pulse pickup 12 and directed to an absorber (not shown).

[0052] Instead of the diagram shown, the selection unit 12 and the power setting device 6 can be configured as a single element.

[0053] Instead of a single seed laser pulse 11, two or more adjacent seed laser pulses 11 can be selected as “input laser pulse trains” (pulse groups), which pass through optical element 1 and are emitted from optical element 1 as output laser pulse trains.

[0054] exist Figure 4 In the laser system 4', an optical amplifier 13 for amplifying the input laser pulse 2' is arranged between the power setting device 6 and the optical component 1. In this case, the optical amplifier 13 has a minimum time period without amplification predefined by the inversion establishment required for minimum gain in the optical amplifier 13, and a maximum time period predefined by the inversion establishment required for maximum gain in the optical amplifier 13. The minimum time period is based on the fact that after pulse amplification, inversion must first be re-established in the gain medium of the optical amplifier 13 to ensure inter-pulse stability. The maximum time period prevents excessively long pulse pauses and therefore excessively high gains, which would lead to undesirable pulse enhancement.

[0055] When the time interval between two output laser pulses 3 is greater than the maximum time interval, the control unit 7 inserts another input laser pulse as a sacrificial laser pulse 14' between the two input laser pulses 2'. This sacrificial laser pulse is separated from the second input pulse 2 to be amplified by at least a minimum time interval and at most a maximum time interval. For this purpose, the pulse source 5 is correspondingly time-controlled by the control unit 7 to provide another laser pulse as the sacrificial laser pulse 14'. The two input laser pulses 2' and the sacrificial laser pulse 14' are amplified by the optical amplifier 13 to form laser pulses 2, 14. Another coupling output unit 15 (e.g., in the form of an AOM or EOM) arranged between the optical amplifier 13 and the optical element 1 is time-controlled by the control unit 7 such that the amplified sacrificial laser pulse 14 is coupled out and directed to an absorber (not shown). The two amplified input laser pulses 2 pass through the optical element 1 (e.g., a conversion crystal) and arrive at the output terminal 9 as output pulses 3 at the requested time.

[0056] The power setting device 6 can also be integrated into the pulse source 5 instead of being located externally (as shown in the figure). Instead of being arranged in front of the optical component 1 (as shown in the figure), another coupling output unit 15 can also be arranged behind the optical component 1 to couple the amplified sacrificial pulse 14' out.

[0057] Figure 5 The second laser system 4" shown is Figure 3 and Figure 4The only difference between the laser systems 4 and 4' is that the pulse source 5 here includes a power regulator 16, which is controlled by the control unit 7 of the laser pulse generator 10, so as to generate input laser pulses 2 with predetermined, selectable different pulse energies and pulse times. Alternatively, the pulse energy can also be set by a power setting device 6 arranged in the pulse generator 10.

[0058] The following describes a computational model for calculating the abstract temperature T of optical component 1.

[0059] The transient response of the laser efficiency of optical component 1 follows a cooling or heating process. If the effective temperature or temperature difference of the "cold" equilibrium state of optical component 1 is known, the power setting device 6 can pre-compensate the output power. In this case, the temperature difference can be understood as a correction variable and typically does not correspond to the actual temperature of the laser system 4, 4', 4"

[0060] The transfer function h of optical component 1 will be explained below by the input pulse energy E of pulse 2 located in front of and behind optical component 1, respectively. in The output pulse energy E of pulse 3 out To describe it, the optical component also experienced a contribution ΔT.

[0061]

[0062] The model of h can be represented as follows, for example:

[0063]

[0064] In this case, let This is the characteristic curve of optical component 1 in the cold state (ΔT = 0). This characteristic curve can be experimentally measured using low heating power (large pulse interval) and stored in a table. Assume that for h and Within the relevant values ​​and definitions, their reciprocals h and They exist separately.

[0065] The development of the temperature difference / correction variable ΔT can be described, for example, as a differential equation with respect to time t, and constitutes an initial value problem.

[0066]

[0067] For such cooling or heating processes, τ and Let represent the intrinsic time constant and the variable heat term, respectively, and the solution for ΔT(t) must be known. In this case, the heat term... It can make a negative or positive contribution to ΔT.

[0068] The differential equation at time t is obtained through the pulsed operation of the laser. The natural discretization of time, these moments are always associated with the time interval Δt of the corresponding previous laser pulse. i Related. In the following text, ΔT i With ΔT(t) i Synonyms. Here, the time interval Δt i Isometric spacing is not required. This time discretization enables numerical solution schemes, such as those described using finite difference finite differences.

[0069]

[0070] Heating power Composed of pulse energy E p (t i ) = E p,i The discrete pulse group is generated.

[0071] Because the pulse durations are both much shorter than the time constant τ, therefore, due to the heat q(t) i The possible temperature changes will not produce significant discretization errors in the results. In this case, q(t) i It typically depends non-linearly on the pulse energy propagated by optical element 1, and is referred to below as q(E). p,i The supplied heat can be described, for example, via E. p,i Approximating with a polynomial of any order n in the polynomial:

[0072]

[0073] In this context, the subscript p distinguishes between input pulse energy (in) and output pulse energy (out), which is crucial for the heating process. For example, the optical nonlinear crystal used for frequency conversion in optical component 1 typically absorbs light to different degrees at the input and output wavelengths. In the chosen example, p = in is intended to indicate a primary dependence on the input pulse. Here, the output pulse energy E... out Calculated using h(ΔT).

[0074] Effective temperature difference ΔT i It is incorporated into the calculation almost in real time at all times. In the cold state, the initial value is ΔT0 = 0. It has pulse energy E. p,i Each requested (i-th) pulse produces an additive input q(E) to ΔT. p,i Furthermore, the cooling process occurs during the stagnation period, during which no pulse propagates through optical element 1. For example, the following is given for calculating ΔT based on the i-th pulse. i Explanation of the order:

[0075] a) The time of stagnation Δt in m steps i The cooling during the period, where k = 1…m and

[0076] ·

[0077] ·

[0078] b) Press 6 to select E in,i E out,i Corresponding to the requested output pulse energy E out,i | soll Therefore, in this example:

[0079] c) Changes in temperature:

[0080] If, for example, a long time interval occurs between pulses and the condition Δt i << τ is no longer satisfied (this will be in If the calculation results in a significant error, then iterative processing of the secondary point a) is necessary. Maximum discretization step Δt d,max =α·τ is necessary such that Δt = ... in all m steps i,k <Δt d,max Applicable. In this case, α << 1 should be selected, for example, α = 0.01 or even less. The number of steps m is selected individually for each i-th pulse interval according to these criteria. The correction calculated in b) is implemented by the control unit 7 through the control power setting device 6 for each pulse.

[0081] For example, this laser control can be implemented on a microcontroller or FPGA.

[0082] When multiple factors contribute to the thermal modification of the output pulse parameters, the p effective temperatures ΔT l This can be included in the calculation, which produces the total correction ΔT. 总 :

[0083]

[0084] This includes p discretized differential equations that must be solved for each i-th laser pulse, and each equation contains an associated heating term. and time constant τ l :

[0085]

[0086] Each ΔTl,i The calculations can be performed according to schemes a) through c) above. For example, different contributions can be obtained by varying the absorption rates at different wavelengths during frequency conversion or by varying the heat of different mechanical components.

[0087] For ΔT i The solution, besides the initial value ΔT(t) i＝0 In addition to ), it is also necessary to determine the mapping q(E) in ) and time constant τ. In the constant calorific term In this case, the differential equation of ΔT(t) has a simple solution, where f rep = constant, and the initial value ΔT(t=0)=0:

[0088]

[0089] Therefore, by making the calibration function (where b(E) in,j )=τ·f rep ·q(E in,j Adapted to output pulse energy E out The time constant τ and q(E) are determined by the measurement results of the stability performance. in This is possible because of the initial temperature ΔT0 and the constant pulse energy E during the measurement. in / E out Both are known. During the measurement of stable performance, the laser system starts from a cold state with a constant input pulse energy E. in and a constant pulse repetition frequency f rep =1 / Δt i = Constant operation, and with a sufficiently short time interval Δt mess <<τ records and stores the output pulse energy or power.

[0090] For at least n different stability curves, combined with n different, fixed heating powers or pulse energies E in,j (where j = 1, 2, ..., n), the measurement results of the stability of the repeated output pulse energy ensure that there are at least n measurement result series, thereby clearly determining the heat contribution. and its coefficient a u .

Claims

1. A method for generating an output laser pulse (3) from an input laser pulse (2) having a previously known pulse energy and a pulse interval, wherein, The input laser pulse (2) passes sequentially through the optical element (1) whose power efficiency is related to temperature, thereby heating the optical element (1) and being emitted as the output laser pulse (3) from the optical element (1) used to set the corresponding pulse power. Its features are, Based on all previous input or output laser pulses (2, 3) that contribute to the current heating of the optical component (1), the current temperature (T) or current temperature difference (ΔT), or temperature-related current parameters of the optical component (1) are calculated. Based on the calculated current temperature (T), calculated current temperature difference (ΔT), or calculated current parameters, the power of the current input laser pulse (2) is set such that the deviation of the pulse energy included in the associated output laser pulse (3) from the predetermined pulse energy is less than 5%.

2. The method as described in claim 1, characterized in that, The deviation between the pulse energy of the associated output laser pulse (3) and the predetermined pulse energy is less than 2%.

3. The method as described in claim 2, characterized in that, The pulse energy included in the associated output laser pulse (3) is equal to the predetermined pulse energy.

4. The method as described in claim 1, characterized in that, The optical component (1) amplifies the input laser pulse (2) or performs frequency conversion on it.

5. The method according to any one of claims 1 to 4, characterized in that, Before passing through the optical element (1), the power of the current input laser pulse is set by adjusting the pulse shape of the current input laser pulse (2), in particular by adjusting the amplitude of the current input laser pulse (2) and / or at least one of the two pulse edges of the current input laser pulse (2).

6. The method according to any one of claims 1 to 4, characterized in that, When generating the current input laser pulse (2), the power of the current input laser pulse is already set based on the calculated current temperature (T), the calculated current temperature difference (ΔT), or the calculated current parameters.

7. The method according to any one of claims 1 to 4, characterized in that, The input laser pulse (2) is amplified in front of the optical component (1).

8. The method as described in claim 7, characterized in that, At least one input laser pulse is amplified as a sacrificial laser pulse and coupled out from the path of the amplified input laser pulse (2) in front of the optical element (1).

9. The method according to any one of claims 1 to 4, characterized in that, Multiple adjacent input laser pulses (2) pass through the optical element (1) as a laser pulse train and exit from the optical element (1) as an output laser pulse train.

10. The method according to any one of claims 1 to 4, characterized in that, The input laser pulse (2) is provided at the following time, such that the output laser pulse (3) arrives at the output terminal (9) at a separately requested time.

11. The method according to any one of claims 1 to 4, characterized in that, Each laser pulse is selected from a pulse sequence of laser pulses (11) with known pulse energies, and is provided as an input laser pulse (2) with known pulse energies and pulse intervals.

12. The method according to any one of claims 1 to 4, characterized in that, Laser pulses with known pulse energy and pulse interval are generated, and laser pulses with known pulse energy and pulse interval are generated as input laser pulses (2).

13. A laser system (4) for generating an output laser pulse (3) from an input laser pulse (2) having a previously known pulse energy and a pulse interval, comprising: A pulse source (5) is used to provide an input laser pulse (2) having a previously known pulse energy and pulse timing. An optical component (1) whose power efficiency is temperature-dependent is passed through by the input laser pulse (2) and simultaneously becomes heated, wherein, The input laser pulse (2) is emitted as the output laser pulse (3) from the optical component (1). A power setting device (6) is used to set the corresponding pulse power of the input laser pulse (2), and The control unit (7) is programmed to calculate the current temperature (T) or current temperature difference (ΔT) of the optical element (1), or a temperature-related parameter, based on all previous input laser pulses or output laser pulses (2, 3) that contribute to the current heating of the optical element (1), and to manipulate the power setting device (6) for the current input laser pulse (2) based on the calculated current temperature (T), the calculated current temperature difference (ΔT), or the calculated current parameter, such that the deviation of the pulse energy included in the associated output laser pulse (3) from the predetermined pulse energy is less than 5%.

14. The laser system as described in claim 13, characterized in that, The deviation between the pulse energy of the associated output laser pulse (3) and the predetermined pulse energy is less than 2%.

15. The laser system as claimed in claim 14, characterized in that, The pulse energy included in the associated output laser pulse (3) is equal to the predetermined pulse energy.

16. The laser system as claimed in claim 13, characterized in that, The optical component (1) is an optical amplifier for amplifying the input laser pulse (2), or a conversion crystal for converting the frequency of the input laser pulse (2).

17. The laser system as claimed in any one of claims 13 to 16, characterized in that, The power setting device (6) is configured as an acousto-optic modulator or electro-optic modulator for adjusting the pulse shape of the current input laser pulse (2), or the power setting device is formed by adjusting (16) the power of the laser pulse (2) generated by the pulse source (5) as the input laser pulse (2).

18. The laser system as claimed in any one of claims 13 to 16, characterized in that, An optical amplifier (13) for amplifying the input laser pulse (2) is arranged in front of the optical component (1).

19. The laser system as claimed in claim 18, characterized in that, A coupling output unit (15), controlled by the control unit (7), for coupling the amplified input laser pulse, which is a sacrificial laser pulse, from the path of the input laser pulse (2), and particularly in the form of an acousto-optic modulator or an electro-optic modulator, is located behind the amplifier (13) and particularly in front of the optical component (1).

20. The laser system as claimed in any one of claims 13 to 16, characterized in that, The pulse source (5) includes: a laser pulse generator (10) for generating laser pulses (11) having known, in particular, identical pulse energies; and a selection unit (12) controlled by the control unit (7) for selecting some of the laser pulses (11) as input laser pulses (2) at previously known pulse times.

21. The laser system as claimed in any one of claims 13 to 16, characterized in that, The pulse source (5) includes a laser pulse generator (10) controlled by the control unit (7) to generate an input laser pulse (2) with a predetermined pulse energy and pulse timing.

22. A control program product comprising a code medium adapted to perform all steps of the method as claimed in any one of claims 1 to 12 when the program is run on a control unit (7) of a laser system (4) as claimed in any one of claims 13 to 21.

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