Delivering high power laser pulses

Abstract

A delivery system is provided that includes a pulse generator and a first pulse supplier including a first fiber optic path, a first pulse amplifier, and a first delivery end. The pulse generator generates a first low-power laser pulse having a predefined power to avoid or minimize distortion of the first low-power laser pulse. The first pulse amplifier amplifies the first low-power laser pulse to produce a first high-power laser pulse having a predefined power to operate a first end component connectable with the first delivery end. The first fiber path has an initial section that delivers a first low power laser pulse from the pulse generator to the first pulse amplifier, and a final section that delivers a first high power laser pulse from the first pulse amplifier to the first delivery end. The first pulse amplifier is arranged at a position along the first fiber path corresponding to a distal position relative to the pulse generator or a proximal position relative to the first delivery end. Methods and computer programs adapted to be performed by / at such delivery systems are also provided.

Description

[0001] This application claims the benefit of European patent application EP22382755.1 filed on August 3, 2022.

[0002] The present disclosure relates to a delivery system for delivering one or more high power laser pulses and, further, to a method and a computer program for operating a delivery system for delivering one or more high power laser pulses. Background Art

[0003] Optical fiber is a glass filament that can transmit signals on light waves. The signal can be a pulse that conforms to a modulated message transmitted from one location to another, or the same data information. The signal can also be a pulse or pulse train of predefined characteristics that is delivered to an endpoint for a wide range of applications. These systems share the optical fiber physical path and therefore share the inherent problems of light propagation through this medium, such as attenuation, dispersion, and nonlinear effects. Their effects can reduce the amount of bandwidth in the case of communication applications and destroy the specifications of the delivered pulse after a few meters in pulse delivery applications.

[0004] Known delivery systems are used to deliver one or more pulse trains to a delivery end (or endpoint) via an optical fiber path. The pulse requirements at the endpoint may include predefined power, duration and / or shape parameters, and meeting these requirements may be important to ensure good system performance. If the pulse duration is ultrashort (e.g., in the picosecond or femtosecond range), dispersion and nonlinear effects may have an adverse effect, which may result in poor performance of the system. As the length of the optical fiber carrying the pulses increases, meeting the minimum requirements or specifications at the delivery end may become more difficult.

[0005] Radiation-based (e.g. THz-based) measurement systems and the like are suitable solutions, for example, for accurately determining the thickness of multilayer materials in a non-contact and non-destructive manner. Such technology has proven to be very suitable for industrial applications, such as the automotive, aerospace industry, etc. These systems can also be used to detect defects or shortcomings other than material thickness, such as deformations, inappropriate holes, discontinuities, etc.

[0006] Such radiation-based systems experience difficulties associated with long-distance propagation of ultrashort laser pulses in optical fibers, as the long paths that the laser pulses have to traverse or travel may result in distortions of the temporal shape and / or spectrum of the laser pulses. Thus, it may be difficult to simultaneously meet radiation-based measurement requirements, such as, for example, accuracy / performance and laser transmission over long distances.

[0007] It is an object of the present disclosure to provide new methods, systems and computer programs aimed at improving prior art ways of delivering high power laser pulses. Summary of the invention

[0008] In one aspect, a delivery system for delivering one or more high-power laser pulses is provided. The delivery system includes a pulse generator and a first pulse supply, the first pulse supply including a first optical fiber path, a first pulse amplifier, and a first delivery end. The pulse generator is configured to generate a first low-power laser pulse having a predefined power to avoid or minimize deformation of the first low-power laser pulse along the first pulse supply. An initial section of the first optical fiber path is configured to transmit the first low-power laser pulse from the pulse generator to the first pulse amplifier. The first pulse amplifier is configured to amplify the first low-power laser pulse to generate a first high-power laser pulse, the first high-power laser pulse having a predefined power to operate a first end assembly connectable to the first delivery end. A final section of the first optical fiber path is configured to transmit the first high-power laser pulse from the first pulse amplifier to the first delivery end. The first pulse amplifier is arranged at a position along the first optical fiber path corresponding to a distal position relative to the pulse generator or a proximal position relative to the first delivery end.

[0009] Minimizing the deformation of the laser pulse may refer to the goal of causing the pulse to be below a deformation threshold or within a predictable deformation range. The amplification of the pulse may refer to an increase in the power of the pulse required by the end component to be operated by the amplified pulse. For example, the pulse amplifier may be configured to amplify the power of the low-power laser pulse by 5 to 20 times, 10 to 20 times, or any estimated necessary or convenient multiple. The concepts of proximal and distal ends are well known in the technical field to which the present disclosure relates. According to the known concepts, the proximal / distal position of the first pulse amplifier may be represented by the first pulse amplifier being closer to the first delivery end than the pulse generator, or in other words, the length of the initial segment is greater than the length of the final segment. For example, the initial segment and the final segment of the first optical fiber path may have a length ratio of, for example, 5 / 1, 4 / 1, 3 / 1, 2 / 1, 1.5 / 1…n / 1 (where n>1). The length ratio of n / 1 may refer to the length of the initial segment being n*m and the length of the final segment being 1*m, where m>=1. For example, a length ratio of 5 / 1 may mean that the length of the initial segment is 5 (5*1) or 10 (5*2) or 15 (5*3) etc., and the length of the final segment is 1 (1*1) or 2 (1*2) or 3 (1*3) etc., respectively.

[0010] These delivery systems can operate better than prior art systems for the same or similar purposes because the low power laser pulse (or pulse train) traverses a large portion of the fiber path and is amplified at a point of the fiber path near or close to the delivery end. It has been demonstrated that the low power laser pulses are less susceptible to distortion due to dispersion and / or nonlinear effects inherent in propagation through optical fiber, and therefore a better quality high power laser pulse can ultimately be delivered. The fact that the low power laser pulses are amplified at the final or nearly final point of the fiber path allows the high power laser pulses to arrive at the delivery end more accurately than prior art systems of the same or similar type.

[0011] The delivery system may further comprise a first pulse conditioner configured to modify or condition the first low power laser pulse or the first high power laser pulse or both to compensate for dispersion and / or nonlinear effects of the first pulse supply. Dispersion and nonlinear effects may increase due to factors such as, for example, long length, high pulse power, etc. The fact that the low power laser pulse (or pulse train) traverses a large portion of the optical fiber path may reduce dispersion and nonlinear effects and thus may meet the minimum requirements of the delivery end in a better manner.

[0012] The first pulse conditioner may be included in the pulse generator or in the first pulse amplifier or in the first optical fiber path. In the case where the first pulse conditioner is included in the first optical fiber path, it may include an optical fiber section having a dispersion parameter opposite to the dispersion parameter of all or part of the remaining optical fiber in the first optical fiber path.

[0013] For multiple intended (or even unintended) applications of the delivery system, an initial segment or a final segment, or both, of the first optical fiber path has an oversized length. Such an oversized length may allow the delivery system to be used in different applications (having the same or similar manufacturing specifications) requiring more or less distance between the pulse generator and the first delivery end. An optical fiber path having an oversized length provides great flexibility in using the delivery system disclosed herein, since the same delivery system may be used for multiple applications requiring (very) different distances between the pulse generator and the delivery end. For example, delivery systems for different (and potentially different) applications may be uniformly configured, cheaper multi-purpose delivery systems may be designed and manufactured accordingly, etc. In an example, the oversized optical fiber may be retractable and extendable, or coilable and non-coilable, such that the remaining optical fiber may remain coiled or retracted, which may be deployed or extended when needed or desired.

[0014] The initial segment of the first fiber path can be extended by including or gathering therein a dispersion-free fiber segment, which may include, for example, fiber segments having dispersion parameters opposite to each other. If the original length of the fiber path is not sufficient for a given application, the fiber extensibility may add even greater flexibility to the delivery system according to the present disclosure, since the fiber extensibility may allow the same delivery system to be used for (even completely or substantially) unexpected applications that require a longer distance between the pulse generator and the delivery end. An implementation with such fiber extensibility may imply connections or links between different fiber sections, which may cause dispersion and nonlinear effects to the laser pulse or laser pulse train when transmitted through the interconnected fiber sections. In a delivery system according to the present disclosure, it may be critical in an implementation with different fiber sections connected to each other that a low-power laser pulse traverses or travels a large portion of the fiber path (from the pulse generator to almost the delivery end). Since low-power pulses are less susceptible to dispersion and, in particular, nonlinear effects than high-power pulses, a delivery system with interconnected fiber sections according to the present disclosure may be easier and optimally implemented, and therefore cheaper than prior art delivery systems. With this implementation, a pre-existing delivery system configured to operate at a given distance between the pulse generator and the delivery end can be adapted to operate at a longer distance between the pulse generator and the delivery end in a very easy and cheaper manner.

[0015] In an implementation, the first low power laser pulse and the first high power laser pulse may be femtosecond or ultrashort laser pulses. Additionally or alternatively, the first low power laser pulse and the first high power laser pulse may have a wavelength between 1500 nm and 1600 nm. Additionally or alternatively, all or part of the first fiber path may maintain polarization in order to, for example, avoid or minimize possible polarization-dependent dispersion effects.

[0016] According to the delivery system which can be named as a dual supply method, a second pulse supplier can also be included, which includes a second optical fiber path, a second pulse amplifier and a second delivery end. In this dual supply method, the pulse generator can also be configured to generate a second low-power laser pulse, and the second low-power laser pulse has a predefined power to avoid or minimize the deformation of the second low-power laser pulse along the second pulse supplier. The initial section of the second optical fiber path can be configured to transmit the second low-power laser pulse from the pulse generator to the second pulse amplifier. The second pulse amplifier can be configured to amplify the second low-power laser pulse to generate a second high-power laser pulse, which has a predefined power to operate the second end component that can be connected to the second delivery end. The last section of the second optical fiber path can be configured to transmit the second high-power laser pulse from the second pulse amplifier to the second delivery end. Still in the dual supply implementation, the second pulse amplifier can be arranged at a position along the second optical fiber path corresponding to a distal position relative to the pulse generator or a proximal position relative to the second delivery end. The second pulse supplier can have the same configuration as the first pulse supplier.

[0017] Delivery systems according to the dual supply method may allow their use in applications where it is necessary to supply laser pulses or pulse trains to two end components. For example, such a delivery system may be ideal for implementing radiation-based applications that require a radiation transmitter and a radiation receiver. Specific applications of this type may be THz radiation-based applications that are intended, for example, to inspect materials or objects with the goal of detecting thickness, holes, discontinuities, deformities, general defects, etc.

[0018] According to a dual supply implementation, the pulse generator may include a dual output laser system configured to generate both a first low power laser pulse and a second low power laser pulse. Alternatively, the pulse generator may include a splitter configured to split a single or main low power laser pulse generated at the pulse generator into a first version and a second version of the single or main low power laser pulse, the first version corresponding to the first low power laser pulse and the second version corresponding to the second low power laser pulse, or vice versa.

[0019] Still according to the dual supply method, the delivery system may further include a synchronizer configured to synchronize the transmission of the first low-power laser pulse and the second low-power laser pulse with each other. This synchronization may be based on the manner in which the first high-power laser pulse and the second high-power laser pulse arrive at the first delivery end and the second delivery end respectively with a predefined time difference between each other in use, and the transmission of one of the first low-power laser pulse and the second low-power laser pulse is time-adjusted. The synchronizer may include a repetition rate controller configured to control or modulate the repetition rate of the first low-power laser pulse and the second low-power laser pulse. The repetition rate controller may be integrated in a system with two synchronized lasers, and / or may use technologies such as ASOPS (Asynchronous Optical Sampling System) and / or ECOPS (Electronically Controlled Optical Sampling System). Alternatively, the synchronizer may include a mechanical delay line configured to time-adjust the transmission of one of the first low-power laser pulse and the second low-power laser pulse. Therefore, the mechanical delay line may be arranged only at one of the first optical fiber path and the second optical fiber path. A skilled person will know how to implement this synchronization depending on the specific target application.

[0020] In an example, the lengths of both the first optical fiber pathway and the second optical fiber pathway may be adjusted and / or tuned by adding or subtracting substantially the same amount of optical fiber length.

[0021] A provider system for providing high-power laser pulses may also be provided herein, the provider system comprising a delivery system according to a dual supply method and another delivery system also according to the dual supply method. Such a provider system may therefore correspond to a method that may be named a quadruple supply method. A provider system of any number of delivery systems according to the dual supply method may correspond to a method that may be named a multi-supply method, which may be defined or obtained by extending the same or similar principles as described for the quadruple supply method. Therefore, provider systems according to sextuple, octuplet, ..., n-tuple supply methods may also fall within the scope of the present disclosure. According to this multi-supply method, a large number of (even unexpected) applications may be covered.

[0022] In an example according to what may be named a dual THz supply method, the first end component may be a THz transmitter and the second end component may be a THz receiver, or vice versa, the THz transmitter and the THz receiver being in accordance with a THz measurement head connectable to a delivery system. In particular, a THz measurement system may be provided comprising a delivery system according to the dual THz supply method and a connectable THz measurement head connected to the delivery system.

[0023] According to a method which can be named as a quadruple THz supply method, a supply system can be provided which includes a first delivery system according to a dual THz supply method and a second delivery system also according to a dual THz supply method. In particular, a THz measurement system can be provided which includes one of the supply systems, a THz measurement head connectable to the first delivery system connected thereto, and a THz measurement head connectable to the second delivery system connected thereto. The same or similar considerations explained with respect to the multi-supply or n-tuple supply method can be extrapolated to such a THz supply method.

[0024] In another aspect, a method of operating a delivery system (for delivering one or more high-power laser pulses) comprising a pulse generator and a first pulse supply is provided, the first pulse supply comprising a first optical fiber path, a first pulse amplifier and a first delivery end, and the first pulse amplifier is arranged at a position along the first optical fiber path corresponding to a distal position relative to the pulse generator or a proximal position relative to the first delivery end. Such a method of operating a delivery system comprises operating the pulse generator to generate a first low-power laser pulse, the first low-power laser pulse having a predefined power to avoid or minimize deformation of the first low-power laser pulse along the first pulse supply, the first low-power laser pulse being transmitted from the pulse generator to the first pulse amplifier through an initial segment of the first optical fiber path. The method of operating the delivery system also comprises operating the first pulse amplifier to amplify the first low-power laser pulse to generate a first high-power laser pulse, the first high-power laser pulse having a predefined power to operate a first end assembly connectable to the first delivery end, the first high-power laser pulse being transmitted from the first pulse amplifier to the first delivery end through a final segment of the first optical fiber path.

[0025] In yet another aspect, a computer program is provided that includes program instructions for causing a system or computing system to perform a method of operating a delivery system to deliver one or more high power laser pulses, such as those described in other parts of this disclosure. These computer programs may be embodied on a storage medium and / or carried on a carrier signal.

[0026] In yet another aspect, a computing system for operating a delivery system for delivering one or more high power laser pulses is provided, the computing system comprising a memory and a processor, which embodies instructions stored in the memory and executable by the processor, and the instructions include one or more functions for performing methods of operating a delivery system, such as those described in other parts of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Non-limiting examples of the present disclosure will now be described with reference to the accompanying drawings, in which:

[0028] Figure 1 is a block diagram schematically illustrating a delivery system for delivering one or more high power laser pulses according to an example.

[0029] Figure 2 is a block diagram schematically illustrating a delivery system for delivering one or more high power laser pulses according to other examples.

[0030] Figure 3 is a block diagram schematically illustrating a delivery system for delivering one or more high power laser pulses according to yet other examples.

[0031] Figure 4 is a block diagram schematically illustrating a delivery system for delivering one or more high power laser pulses according to yet other examples.

[0032] Figure 5 is a block diagram schematically illustrating a delivery system for delivering one or more high power laser pulses according to further examples.

[0033] Figure 6 is a block diagram schematically illustrating a delivery system for delivering one or more high power laser pulses according to yet other examples.

[0034] Figure 7 is a flow chart schematically illustrating a method of operating a delivery system for delivering one or more high power laser pulses according to an example. DETAILED DESCRIPTION

[0035] Figure 1 1 is a block diagram schematically illustrating a delivery system 100 for delivering one or more high-power laser pulses 114 according to an example. As shown, the delivery system 100 may include several modules or units, or groups of modules or units, such as a pulse generator 102 and a first pulse supply 115. The first pulse supply 115 may include various modules or units, such as a first optical fiber path 103, 107 covering a first length 104, 108, a first pulse amplifier 105, and a first delivery end 109. The delivery system 100 may correspond to a single supply method in the sense that only one high-power laser pulse (or pulse train) may be delivered or delivered.

[0036] The first optical fiber path 103, 107 may include an initial optical fiber section 103 connecting the pulse generator 102 and the pulse amplifier 105 and a final optical fiber section 107 connecting the pulse amplifier 105 and the first delivery end 109. The first pulse amplifier 105 may be arranged at a position along the first optical fiber path 103, 107 corresponding to a distal position relative to the pulse generator 102 or a proximal position relative to the first delivery end 109. In other words, the first pulse amplifier 105 may be arranged at a position very close to the first delivery end 109 compared to the pulse generator 102.

[0037] The pulse generator 102 may include a laser pulse generator 101 configured to generate a first low-power laser pulse 111 having a predefined power to avoid or minimize deformation of the first low-power laser pulse 111 along a first pulse supply 115. As shown, due to the proximal position of the first pulse amplifier 105 with respect to the first delivery end 109, the first low-power laser pulse 111 will be propagated (at low power) through a large portion of the first optical fiber path 103, 107. Ideally, the predefined power of the first low-power laser pulse 111 may be as low as possible, taking into account, for example, the minimum power at which a module or unit of the pulse generator 102 and / or the first pulse supply 115 may operate. The initial optical fiber segment 103 of the first optical fiber path may be configured to transmit the first low-power laser pulse 111 (from the pulse generator 102 to the first pulse amplifier 105) with slight or negligible deformation due to the predefined low power therefor, even if the first low-power laser pulse 111 is to travel a substantially long distance 104.

[0038] The first pulse amplifier 105 can be configured to amplify the first low power laser pulse 111 to generate a first high power laser pulse 113 having a predefined power to operate a first end assembly 110 that can be connected to the first delivery end 109. It is known that any given end assembly 110 may require a pulse power for operation, and therefore it is also known that the amplification from low power to high power is performed by the first pulse amplifier 105, so details about this are not provided herein. For example, the first pulse amplifier 105 can be configured to amplify the power of the first low power laser pulse 111 by 5 to 10 times, or 10 to 20 times, or according to any other suitable ratio depending on the first end assembly 110 to be operated. The final fiber section 107 of the first optical fiber path can be configured to transmit the first high power laser pulse 113 from the first pulse amplifier 105 to the first delivery end 109, wherein the first high power laser pulse 113 has a slight or negligible or minimized deformation 114 due to at least the proximal position of the first pulse amplifier 105 with respect to the first delivery end 109. The first delivery end 109 may be configured to deliver the first high power laser pulse 113 to the first end assembly 110 when connected to the first end assembly 110 .

[0039] The delivery system 100 may also include other modules or units, such as a first pulse conditioner, which may include one or more conditioner modules 112, 106. The conditioner module 112 may be associated with or coupled to or included in the pulse generator 102 and configured to modify or condition the first low-power laser pulse 111 to compensate for dispersion and / or nonlinear effects caused by its transmission through the initial optical fiber segment 103 having a known and defined length 104. In the particular scenario shown, the first low-power laser pulse 111 is shown to be wider at the output of the conditioner module 112 than at the input of the first pulse amplifier 105. Thus, it is intended to indicate that the conditioner module 112 can explicitly modify or condition the first low-power laser pulse 111 so that the dispersion and / or nonlinear effects caused by the optical fiber path 103 (having a known and defined length 104) cause the first low-power laser pulse 111 to produce an appropriate minimum or optimal specification (e.g., width) at the input of the first pulse amplifier 105. These appropriate minimum or optimal specifications may be pursued and motivated in the manner noted to minimize or optimally perform the first pulse amplifier 105 .

[0040] The conditioner module 106 may be associated with or coupled to or included in the first pulse amplifier 105 and configured to modify or condition the first high power laser pulse 113 to compensate for dispersion and / or nonlinear effects caused by its transmission through the final fiber segment 107. In the particular case depicted, two versions or occurrences of the first high power laser pulse 113, 114 are shown. The pulse occurrence 113 corresponds to the pulse occurrence output by the conditioner module 112, and the pulse occurrence 114 corresponds to the pulse occurrence received at the first delivery end 109. The pulse occurrence 113 is shown as wider than the pulse occurrence 114. This difference in width is intended to reflect that the conditioner module 106 may specifically modify or condition the first high power laser pulse 113 so that the dispersion and / or nonlinear effects caused by the fiber path 107 (having a known and defined length 108) result in the first high power laser pulse 114 having appropriate minimum or optimal specifications (e.g., width) at the first delivery end 109. These appropriate minimum or optimal specifications may be pursued and motivated in the manner noted so that the first end assembly 110 performs minimally or optimally.

[0041] The conditioner module or unit may be arranged at any point of the first fiber path 103, 107, either exclusively or additionally, for the same purpose of compensating for dispersion and / or nonlinear effects. Any pulse conditioning (such as the pulse conditioning described herein) may be primarily used for the first high power laser pulse 114 to arrive at the first delivery end 109 that meets the minimum operating specifications of the first end assembly 110. It is known how to condition the laser pulse according to the fiber path and / or the components to be traversed or traveled by the laser pulse (in the first pulse supply 115) and according to the requirements of the first end assembly 110, so specific details about this are not provided herein. In a specific example, the conditioner module arranged at the first fiber path 103, 107 may include a fiber section having a dispersion parameter opposite to the dispersion parameter of all or part of the remaining fiber in the first fiber path 103, 107. The first end assembly 110 may be a THz based component, such as a THz transmitter or a THz receiver that may require an appropriate laser pulse (or pulse train) to operate.

[0042] The initial fiber segment 103 or the final fiber segment 107 or both (in the first fiber path) may have excessive lengths for a number of intended (or even unintended) applications of the delivery system 100. In particular, the initial fiber segment 103 or the final fiber segment 107 or both may be retractable and extendable, or coilable and non-coilable. Thus, the length 104 of the first segment 103 may be adapted to the intended or desired distance between the pulse generator 102 (with or without the conditioner module 112) and the first pulse amplifier 105, and / or the length 108 of the second segment 107 may be adapted to the intended or desired distance between the first pulse amplifier 105 (with or without the conditioner module 106) and the first delivery end 109. The delivery system 100 may require a larger or smaller length of the initial fiber segment 103 and / or the final fiber segment 107 due to, for example, the larger or smaller size of the objects to be inspected in radiation-based applications. For example, inspection of an aircraft may require a longer length than an automobile or motorcycle. With the proposed adaptive overlength method, the same conveyor system 100 can be used in different applications in a very flexible and versatile manner. Figure 1 In the particular example of , only the initial fiber segment 103 is shown as being oversized, and the remaining fiber path may be coiled / wound 116. Ideally, the remaining fiber may be rolled 116 at a proximal location with respect to the pulse generator 102 so that it is protected, for example, in a cabinet hosting the pulse generator 102.

[0043] The first low-power laser pulse 111 and the first high-power laser pulse 113, 114 may be femtosecond laser pulses, which are represented in the figure as schematic time pulse traces (e.g., obtained using an autocorrelator). Minimum specifications to be met at the delivery point 109 for the connectable end assembly 110 to perform properly may include, for example, a pulse duration between 50 fs and 150 fs and / or a pulse wavelength between 1500 nm and 1600 nm, etc. In an example, all or part of the first optical fiber path 103, 107 may maintain polarization to minimize polarization-dependent dispersion effects.

[0044] Figure 2 is a block diagram schematically illustrating a delivery system 200 for delivering one or more high power laser pulses according to other examples. Figure 2 Similar to Figure 1 , except that it further includes a free-scattering fiber section. Figure 1 The same or similar elements may be referenced in Figure 2 and are used repeatedly in the following description. The delivery system 200 may also correspond to a single supply method in the sense that only one high-power laser pulse (or pulse train) is delivered. The delivery system 200 may include Figure 1 The pulse generator in the embodiment is the same as or similar to the pulse generator 102, and the first pulse supplier 208 may be different from Figure 1 The first pulse supplier 115 of FIG. 1 is shown in the figure that the fiber segment 103 can be extended (and if necessary or desired, extended or extended accordingly) by, for example, including or aggregating free dispersion fiber segments including fiber segments having dispersion parameters opposite to each other. In the specific example shown, the length 104 of the fiber segment 103 has been extended to a longer length 207 by adding additional fiber segments 204, 205 and 206. As shown, the longer length 207 can be generated by the sum of the length 104 (of the fiber segment 103) and the lengths 201-203 (of the fiber segments 206, 205 and 204, respectively). In order to make this fiber extension non-dispersive, the fiber segments 204, 206 can have a dispersion parameter, and the fiber segment 205 can have another dispersion parameter opposite to that of one of the segments 204, 206. Thus, based on the selection of appropriate lengths 201-203, the dispersion due to fiber segments 204, 206 and the dispersion due to fiber segment 205 can be compensated for each other in such a way that the dispersion of the entire added fiber segment 204-206 can be zero or negligible. Figure 1 Different in Figure 2 Two first low-power laser pulses 111 are shown in FIG. 1 , and when transmitted through the optical fiber sections 206 , 205 and 204 , the first low-power laser pulses 111 have substantially the same width, thereby conforming to the dispersion-free fiber section used to extend the original optical fiber section 103 .

[0045] Figure 3is a block diagram schematically showing a delivery system 300 for delivering one or more high-power laser pulses according to yet other examples. Such a delivery system 300 may correspond to a system named herein as a dual supply method in the sense that two (first and second) high-power laser pulses (or pulse trains) are delivered separately to respective end components 304, 305. Such end components 304, 305 may be, for example, a THz transmitter and a THz receiver, respectively, forming a so-called THz measurement head. The delivery system 300 may include a single laser pulse generator 301 and two (first and second) pulse supplies 302, 303 to supply corresponding (first and second) high-power laser pulses (or pulse trains) to respective connectable or connected (first and second) end components 304, 305. Therefore, the device shown in the figure may correspond to a THz-based measurement system according to the dual supply method. The pulse suppliers 302, 303 may have the same or similar or compatible configurations, and are intended to supply respective (first and second) high-power laser pulses (or pulse trains) to respective connectable or connected (first and second) end assemblies 304, 305 in an appropriate manner, for example to operate the corresponding THz measurement heads. The end assemblies 304 and 305 may be appropriately operated by providing first high-power laser pulses and second high-power laser pulses (or pulse trains) that meet the respective minimum specifications of the end assemblies 304 and 305.

[0046] The pulse generator 301 may be configured to generate the first low-power laser pulse and the second low-power laser pulse (to be transmitted and adjusted by the respective first pulse supplier 302 and the second pulse supplier 303) according to a direct generation method or a splitting-based generation method. The direct generation method may be based on, for example, a dual-output laser system (not shown) configured to directly generate both the first low-power laser pulse and the second low-power laser pulse. The splitting-based generation method may be based on, for example, a splitter (not shown) configured to split a single or main low-power laser pulse (generated by, for example, a laser pulse generator in the pulse generator) into a first version and a second version of the main low-power laser pulse. The first version may correspond to the first low-power laser pulse and the second version to the second low-power laser pulse, or vice versa, respectively.

[0047] The delivery system 300 may also include other modules, such as a regulator (not shown), a synchronizer (not shown), etc. The synchronizer may be included in the pulse generator 301 and may be configured to synchronize the transmission of the first low-power laser pulse and the second low-power laser pulse with each other. The synchronization may be performed in such a way that the first high-power laser pulse and the second high-power laser pulse arrive at the first delivery end 304 and the second delivery end 305 respectively with a predefined time difference between each other in use. The synchronizer may include, for example, a repetition rate controller or alternatively a mechanical delay line. The repetition rate controller may be configured to control or modulate the repetition rate of the first low-power laser pulse and the second low-power laser pulse. The mechanical delay line may be configured to time-adjust the transmission of one low-power laser pulse in the first low-power pulsed laser and the second low-power laser pulse with respect to the other low-power laser pulse.

[0048] Since the performance of a delivery system according to the dual-supply approach may depend on simultaneously meeting minimum specifications of the first-end assembly and the second-end assembly, optimal performance may be more difficult to achieve than in the case of a delivery system according to the single-supply approach. However, in the same manner as the single-supply approach, implementation according to the dual-supply approach may also minimize inherent dispersion and nonlinear effects based on the propagation of low-power laser pulses along a large portion of the corresponding optical fiber path.

[0049] Thus, a new scenario is provided that can help deploy technologies in industrial environments that require precision and long fiber path distances. For example, a THz system for controlling the layer thickness of a car body coating may typically require a distance greater than 30 meters and an accuracy within 1 micron. Such a THz system can be implemented using a low-power fiber path length of approximately >20 meters and (thus) a high-power fiber path length of approximately <10 meters. The delivery system according to the present disclosure can enable the long-distance propagation of laser pulses to be utilized to provide optical pulses with optimal or minimum specifications at the corresponding THz antenna under appropriate performance and precision conditions.

[0050] Figure 4 4 is a block diagram schematically illustrating a delivery system 400 for delivering one or more high-power laser pulses according to yet other examples. The particular examples represented also correspond to a dual supply approach, as they can be configured to operate two connectable (or if desired, connected) end assemblies 404, 405 (forming, for example, a THz measurement head). In the illustrated scenario, a synchronizer 406 can be provided external to the pulse generator 401, which can be similar to Figure 1 and Figure 2The pulse generator 102 is different from the pulse generator 401 in that the pulse generator 401 can output two laser pulses instead of one laser pulse. Therefore, the pulse generator 401 may include a pulse generator 407, which is configured to generate a first low-power laser pulse and a second low-power laser pulse, and in some examples, a first regulator module 408 and a second regulator module 409 appropriately regulate the first low-power laser pulse and the second low-power laser pulse, respectively. The first pulse supplier 402 and the second pulse supplier 403 included in the delivery system 400 may also be the same or similar to the pulse suppliers described in other parts of the present disclosure. In the specific example shown, the pulse suppliers 402, 403 can be the same as Figure 2 As depicted, synchronizer 406 can be configured to time-adjust transmission of one of the first low-power laser pulse and the second low-power laser pulse by pulse supplier 403 so as to cause a predefined time difference between one transmission and the other transmission.

[0051] The possibility to transform a dual supply system, which was originally manufactured to a specific original length, in order to cover a longer fiber path than its original length, may provide further opportunities in an industrial context. The transformation may be achieved by adding additional free dispersion fiber segments, as shown by pulse supplies 402, 403. In order to accurately describe the advantages of the delivery system 400 according to the dual supply, the following THz-based example may be assumed. A THz measurement system for controlling the layer thickness of a body coating in a factory manufacturing compact and mid-sized vehicles was originally designed and manufactured to cover a maximum expected distance of, for example, 20 meters. However, the factory started manufacturing larger vehicles that required new distances of, for example, 30 meters or more, and so it was decided to transform the original system to adapt it to the new scenario.

[0052] Figure 4 A specific adaptable implementation 400 according to the present disclosure is shown. A pulse generator 401 can output two low power laser pulses through a first fiber path and a second fiber path in respective pulse supplies 402, 403. A regulator module 409, 408 at the pulse generator 401 can compensate for dispersion and nonlinear effects of optical propagation through the low power section of the first fiber path and the second fiber path (in the pulse supplies 402, 403). Synchronization can be achieved by a mechanical delay unit 406 at the second fiber path (in the pulse supply 403). The implementation can correspond to a TDS-THz system, wherein the first end component 404 is a THz transmitter antenna and the second end component 405 is a THz receiver / detector antenna.

[0053] As shown, two dispersion free fiber segments may be included in the low power segments of the first and second fiber paths (in pulse supplies 402, 403). The two additional dispersion free fiber segments may have the same length to match the lengths of the first and second fiber paths. Even if the modules in pulse generator 401 and pulse supplies 402 and 403 are initially manufactured and properly tuned to the nominal specifications of the original system, slight but potentially significant mistune may occur in the high power laser pulses at antennas 404, 405.

[0054] Advantages of the delivery system 400 may allow dispersion and nonlinear effects to be maintained at tolerable levels and balanced with each other. For example, if the detuning is expressed in pulse durations that are slightly different from the (minimum or optimal) specifications of the antennas 404, 405, the magnitude and sense of the difference may be balanced and / or approximately the same in both antennas 404, 405. This is an important advantage compared to prior art THz systems operating over long distances, where dispersion and nonlinearity may affect the laser pulses passing through the first pulse supply 402 and the second pulse supply 403 in a more uncontrolled or unbalanced or different manner. In the delivery system 400, the difference in pulse duration, for example, may be adjusted or tuned by changing the length of the patch cords (in the pulse supplies 402, 403) of the first and second fiber paths, by enlarging or shortening by the same or similar amount of length.

[0055] Figure 5 is a block diagram schematically illustrating a delivery system 500 for delivering one or more high power laser pulses according to another example. The specific examples represented may correspond to a method that may be named a quadruple supply method because they may be configured to operate four connectable (or, if desired, connected) end components 506-509. End components 506 and 507 may form a first THz measurement head, and end components 508 and 509 may conform to a second THz measurement head. Thus, the apparatus shown in the figure may correspond to a THz-based measurement system according to a quadruple supply method, or in other words a dual head method. The delivery system 500 may include a pulse generator 501 having the same or similar configuration as other pulse generators described herein, except that the pulse generator 501 may output four low power laser pulses instead of one or two low power laser pulses. The delivery system 500 may include two delivery systems according to a dual supply method, such as Figure 3 and Figure 4 In the particular example shown, the pulse supply 502-505 can be connected to Figure 3 The pulse supply in the same or similar. It can also be based on the composition Figure 5The principles underlying the example or any other similar example described herein can be used to provide a delivery system configured to supply more than four high-power laser pulses (or pulse trains) to more than four end assemblies, respectively. A delivery system according to a dual-head or triple-head or quad-head or generally multi-head approach can allow providing several or many THz measurement heads to a THz-based measurement system for contactless inspection or analysis of different parts of the same object or different objects.

[0056] Figure 6 is a block diagram schematically illustrating a delivery system 600 for delivering one or more high power laser pulses according to yet another example. Figure 6 Similar to Figure 5 , and therefore, can be Figure 6 Repeated use of logo in the following description Figure 5 The same or similar elements are referenced by reference numerals. Figure 6 about Figure 5 The difference may be in how the low power laser pulses (or pulse trains) may be generated to be supplied to the corresponding pulse suppliers 502-505 to operate the associated end components 506-509. The pulse generator 501 may be similar to Figure 5 The pulse generator, but in Figure 6 In the case of , it is configured to output two low-power laser pulses 603, 604 instead of four low-power laser pulses. The splitter 601 can be configured or arranged to split the low-power laser pulse 603 into a first version / branch 605 and a second version / branch 606 of the low-power laser pulse 603, the first version / branch 605 will be provided to the pulse supplier 502, and the second version / branch 606 will be provided to the pulse supplier 504. Another splitter 602 can be configured or arranged to split the low-power laser pulse 604 into a first version / branch 607 and a second version / branch 608 of the low-power laser pulse 604, the first version / branch 607 will be provided to the pulse supplier 503 and the second version / branch 608 will be provided to the pulse supplier 505. With this configuration, only one of the low-power laser pulses 603, 604 output by the pulse generator 501 can be time-adjusted with respect to the other of the low-power laser pulses 603, 604 at the pulse generator 501 itself. The device shown in this figure can similarly correspond to a THz-based measurement system according to the quadruple supply method or in other words the dual head method. Figure 6 The principles underlying the example or any other similar examples described herein may be used to provide a delivery system configured to supply more than four high power laser pulses (or pulse trains) to more than four end assemblies, respectively.

[0057] As used herein, the term "module" or "unit" may be understood to refer to software, firmware, hardware, and / or various combinations thereof. Note that modules are exemplary. Modules may be combined, integrated, separated, and / or replicated to support various applications. Furthermore, the functions described herein as being performed by a particular module may be performed by one or more other modules and / or by one or more other devices, instead of or in addition to the functions performed by the particular module described.

[0058] Modules may be implemented across multiple devices, associated or linked to corresponding delivery systems for delivering one or more high power laser pulses as presented herein, and / or associated or linked to other components that may be local or remote to each other. Additionally, modules may be moved from one device and added to another device, and / or may be included in both devices, associated with corresponding delivery systems for delivering one or more high power laser pulses as presented herein. Any software implementation may be tangibly embodied in one or more storage media, such as, for example, a memory device, a floppy disk, a compact disk (CD), a digital versatile disk (DVD), or other device that may store computer code.

[0059] The delivery system for delivering one or more high-power laser pulses according to the present disclosure may be implemented by a computing device, an electronic device, or a combination thereof. The computing device may be an instruction set (e.g., a computer program), and then the delivery system for delivering one or more high-power laser pulses may include a memory and a processor, which specifically implements the instruction set stored in the memory and executable by the processor. These instructions may include one or more functions of executing a corresponding method of operating the delivery system, such as those described with reference to some of the figures.

[0060] In the case of a delivery system for delivering one or more high-power laser pulses implemented solely by electronic means, the controller of the system can be, for example, a CPLD (Complex Programmable Logic Device), an FPGA (Field Programmable Gate Array) or an ASIC (Application-Specific Integrated Circuit).

[0061] In the case where the delivery system for delivering one or more high-power laser pulses is a combination of electronics and computing devices, the computing device may be a set of instructions (e.g., a computer program), and the electronics may be any electronic circuit capable of implementing the corresponding steps of the delivery method for delivering one or more high-power laser pulses presented herein, such as those described with reference to other figures.

[0062] The computer program may be embodied on a storage medium (eg, CD-ROM, DVD, USB drive, computer memory or read-only memory) or carried on a carrier signal (eg, on an electrical or optical carrier signal).

[0063] The computer program may be in the form of source code, object code, a code intermediate source and object code, such as in partially compiled form, or in any other form suitable for implementing a delivery system for delivering one or more high power laser pulses according to the present disclosure. The carrier may be any entity or device capable of carrying a computer program.

[0064] For example, the carrier may comprise a storage medium such as a ROM, for example a CD ROM or a semiconductor ROM, or a magnetic recording medium, for example a hard disk. Furthermore, the carrier may be a transmissible carrier such as an electrical or optical signal, which may be transmitted via an electrical or optical cable or by radio or other means.

[0065] When the computer program is embodied in a signal that can be directly transmitted by a cable or other device or means, the carrier may be constituted by such cable or other device or means. Alternatively, the carrier may be an integrated circuit in which the computer program is embedded, the integrated circuit being suitable for executing or being used for executing the delivery method proposed herein for delivering one or more high-power laser pulses.

[0066] Figure 7 is a schematic diagram showing operations such as Figure 1 and Figure 2 Flow chart of a method for operating a conveying system. Such a method of operating a conveying system may also be referred to herein as an operating method. As shown, the operating method may be initiated (e.g., at block 700) when a start condition (e.g., a request to start the method, etc.) is detected. Figure 7 The operation method can be executed to control or operate according to Figure 1 and Figure 2 The conveying system, therefore, comes from Figure 1 and Figure 2 The reference numerals may be found in Figure 7 It is reused in the following description.

[0067] The method of operation may also include (e.g., at block 701) operating the pulse generator 102 to generate a first low-power laser pulse (or a plurality of pulse trains), the first low-power laser pulse having a predefined power to avoid or minimize deformation of the first low-power laser pulse (or a plurality of pulse trains) along the first pulse supply 115, 209, the first low-power laser pulse (or a plurality of pulse trains) being transmitted from the pulse generator 102 to the first pulse amplifier 105 through the initial segment 103, 208 of the first optical fiber path. The function implemented or implementable at block 701 may be performed to operate, for example, the previously referenced Figure 1 and Figure 2 The described pulse generator 102 . Therefore, the functional details, considerations and principles explained with respect to the described pulse generator 102 may be similarly attributed or attributable to the method block 701 .

[0068] The method of operation may also include (e.g., at block 702) operating the first pulse amplifier 105 to amplify the first low-power laser pulse to generate a first high-power laser pulse having a predefined power to operate a first end assembly 110 connectable to a first delivery end 109, the first high-power laser pulse being transmitted from the first pulse amplifier 105 to the first delivery end 109 via the final section 107 of the first optical fiber path. The function implemented or implementable at block 702 may be performed to operate, for example, the first end assembly 110 connected to the first delivery end 109. Figure 1 and Figure 2 The described pulse amplifier 105 . Therefore, the functional details, considerations and principles explained with respect to the described pulse amplifier 105 may be similarly attributed or attributable to method block 702 .

[0069] The method of operation may further include (e.g., at decision block 703) verifying whether an end condition is met, in which case, Y, the method may be terminated by, for example, transitioning to end block 704, otherwise, N, a new iteration of the method may be initiated by, for example, looping back to block 701 to generate a next first low-power laser pulse (or pulse train). The end condition may include, for example, receiving a user termination request, etc.

[0070] according to Figure 7 The operating methods are suitable for operating a delivery device according to a single supply method, but they can be clearly extended to operate a delivery device according to a multi-supply method based on the functional principles described herein with respect to the operating methods themselves and the delivery devices that can be operated by the methods. For example, elements other than the pulse generator and the pulse amplifier (such as synchronizers and / or regulators) can be operated by operating methods based on the functional principles described herein with respect to synchronizers and / or regulators, respectively.

[0071] Although only a plurality of examples are disclosed herein, other substitutions, modifications, uses and / or their equivalents are possible. In addition, all possible combinations of the described examples are also contemplated. Therefore, the scope of the present disclosure should not be limited by specific examples, but should only be determined by an objective reading of the appended claims.

Claims

1. A delivery system for delivering one or more high-power laser pulses, the delivery system comprising a pulse generator and a first pulse supplier, the first pulse supplier comprising a first optical fiber path, a first pulse amplifier and a first delivery end; wherein: The pulse generator is configured to generate a first low-power laser pulse having a predefined power to avoid or minimize deformation of the first low-power laser pulse along the first pulse supply; an initial segment of the first optical fiber path configured to transmit the first low power laser pulse from the pulse generator to the first pulse amplifier; The first pulse amplifier is configured to amplify the first low-power laser pulse to generate a first high-power laser pulse, the first high-power laser pulse having a predefined power to operate a first end assembly connectable to the first delivery end; a final segment of the first optical fiber path configured to transmit the first high power laser pulse from the first pulse amplifier to the first delivery end; as well as The first pulse amplifier is disposed at a position along the first optical fiber path corresponding to a distal position relative to the pulse generator or a proximal position relative to the first delivery end.

2. The delivery system of claim 1 , further comprising a first pulse conditioner configured to modify or condition the first low-power laser pulse or the first high-power laser pulse or both to compensate for dispersion and / or nonlinear effects of the first pulse supply.

3. The delivery system according to claim 2, wherein: The first pulse conditioner is included in the pulse generator or in the first pulse amplifier or in the first optical fiber path.

4. The delivery system according to claim 3, wherein: The first pulse conditioner is included in the first optical fiber path and includes an optical fiber portion having a dispersion parameter that is opposite to the dispersion parameter of all or a portion of the remaining optical fiber in the first optical fiber path.

5. The delivery system according to any one of claims 1 to 4, wherein: For many contemplated applications of the delivery system, the initial segment or the final segment, or both, of the first optical fiber path have a length that is too great.

6. The delivery system according to any one of claims 1 to 5, wherein: The initial segment of the first optical fiber path can be extended by including or aggregating therein a dispersion free optical fiber segment comprising optical fiber segments having dispersion parameters opposite to each other.

7. The delivery system according to any one of claims 1 to 6, wherein: The first low-power laser pulse and the first high-power laser pulse are femtosecond or ultrashort laser pulses.

8. The delivery system according to any one of claims 1 to 7, wherein: The first low power laser pulse and the first high power laser pulse have a wavelength between 1500 nm and 1600 nm.

9. The delivery system according to any one of claims 1 to 8, wherein: All or part of the first optical fiber path is polarization maintaining.

10. The delivery system according to any one of claims 1 to 9, further comprising a second pulse supplier, wherein the second pulse supplier comprises a second optical fiber path, a second pulse amplifier, and a second delivery end; wherein: The pulse generator is further configured to generate a second low-power laser pulse having a predefined power to avoid or minimize deformation of the second low-power laser pulse along the second pulse supply; an initial segment of the second optical fiber path configured to transmit the second low power laser pulses from the pulse generator to the second pulse amplifier; The second pulse amplifier is configured to amplify the second low-power laser pulse to generate a second high-power laser pulse having a predefined power to operate a second end assembly connectable to the second delivery end; a final section of the second optical fiber path configured to transmit the second high power laser pulses from the second pulse amplifier to the second delivery end; as well as The second pulse amplifier is disposed at a position along the second optical fiber path corresponding to a distal position relative to the pulse generator or a proximal position relative to the second delivery end.

11. The delivery system according to claim 10, wherein: The second pulse supplier has the same configuration as the first pulse supplier.

12. The delivery system according to any one of claims 10 or 11, wherein: The pulse generator includes a dual-output laser system configured to generate both the first low-power laser pulse and the second low-power laser pulse.

13. The delivery system according to claim 10 or 11, wherein: The pulse generator includes a splitter configured to split a single low-power laser pulse generated at the pulse generator into a first version and a second version of the single low-power laser pulse, the first version corresponding to the first low-power laser pulse and the second version corresponding to the second low-power laser pulse, or vice versa.

14. The delivery system of any one of claims 10 to 13, further comprising a synchronizer configured to synchronize delivery of the first low power laser pulse and the second low power laser pulse with each other.

15. The delivery system according to claim 14, wherein: The synchronizer is configured to synchronize the delivery of the first low-power laser pulse and the second low-power laser pulse with each other based on time adjustment of the delivery of one of the first low-power laser pulse and the second low-power laser pulse in such a way that the first high-power laser pulse and the second high-power laser pulse arrive at the first delivery end and the second delivery end respectively with a predefined time difference between each other during use.

16. The delivery system according to any one of claims 14 or 15, wherein: The synchronizer includes a repetition rate controller configured to control or modulate a repetition rate of the first low power laser pulses and the second low power laser pulses.

17. The delivery system according to any one of claims 14 or 15, wherein: The synchronizer includes a mechanical delay line configured to enable the time adjustment of the transmission of one of the first low power laser pulse and the second low power laser pulse.

18. The delivery system according to any one of claims 10 to 17, wherein: The lengths of the first optical fiber path and the second optical fiber path can be adjusted and / or tuned by increasing or decreasing the optical fiber length by substantially the same amount.

19. The delivery system according to any one of claims 10 to 18, wherein: The first end component is a THz transmitter and the second end component is a THz receiver, or vice versa, the THz transmitter and the THz receiver conforming to a THz measurement head connectable to the delivery system.

20. A measurement system comprising the transport system according to claim 19 and a THz measurement head connectable to the transport system.

21. A provider system for providing high power laser pulses, the provider system comprising a delivery system according to any one of claims 10 to 18 and a further delivery system according to any one of claims 10 to 18.

22. A supply system for supplying high power laser pulses, the supply system comprising a first delivery system according to claim 19 and a second delivery system also according to claim 19.

23. A measurement system comprising the supply system according to claim 22, the THz measurement head being connectable to the first transport system connected thereto, and the THz measurement head being connectable to the second transport system connected thereto.

24. A method of operating a delivery system for delivering one or more high power laser pulses, the delivery system comprising a pulse generator and a first pulse supply, the first pulse supply comprising a first fiber path, a first pulse amplifier and a first delivery end, wherein The first pulse amplifier is arranged at a position along the first optical fiber path corresponding to a distal position relative to the pulse generator or a proximal position relative to the first delivery end, and wherein, The method comprises: operating the pulse generator to generate a first low-power laser pulse having a predefined power to avoid or minimize deformation of the first low-power laser pulse along the first pulse supply, the first low-power laser pulse being transmitted from the pulse generator to the first pulse amplifier through an initial segment of the first optical fiber path; and The first pulse amplifier is operated to amplify the first low-power laser pulse to generate a first high-power laser pulse, the first high-power laser pulse having a predefined power to operate a first end component connectable to the first delivery end, the first high-power laser pulse being transmitted from the first pulse amplifier to the first delivery end through a final segment of the first optical fiber path.

25. A computer program comprising program instructions for causing a computing system to perform a method of operating a delivery system for delivering one or more high power laser pulses according to claim 24.

26. The computer program according to claim 25, embodied on a storage medium.

27. A computer program according to claim 25, carried on a carrier signal.

28. A computing system for operating a delivery system for delivering one or more high power laser pulses, the computing system comprising a memory and a processor, the processor embodying instructions stored in the memory and executable by the processor, the instructions comprising functions of performing the method of operating a delivery system for delivering one or more high power laser pulses according to claim 24.

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