ES2356243T3 - FIBER LASER BASED INTERFERENCE SYSTEM. - Google Patents

Abstract

A system of Direct Measures Against IR, DIRCM (10) comprising: detection means (30) to detect a ship (35) that may pose a threat to a mobile platform (20) to which said system is attached; alert means (30) to generate an alert when a ship that represents a threat is detected; acquisition means (40) to generate the data acquisition of said approach while calculating an updated position of said ship that constitutes a real-time threat; fiber laser means (50) for generating a laser beam (70); a mobile turret means (60), coupled with said fiber laser means to direct said laser beam towards said ship; processing means (80) that are associated with said detection means, said acquisition means, said fiber laser means and said mobile turret means; characterized in that said fiber laser means a. they are generating said laser beam as a narrow beam of SW and LW - dual wavelength, high brightness, average power, suitable for interfering said ship; and b. to provide said SW beam, it is a ZBLAN fiber laser doped with Tm / Ho, a Silica fiber laser doped with Tm or a holmium bulk laser pumped by a silica fiber laser doped with Tm; and c. to provide said LW beam, it is a Periodically Polarized Lithium Niobate, PPLN, or Periodically Polarized Stoichiometric Lithium Tantalite, PPSLT, Optical Parametric Oscillator, OPO, pumped by a Yb-doped silica fiber laser or a Germanium and Zinc Phosphide , ZGP, OPO pumped by a bulk Ho laser pumped by a Tm doped silica fiber laser. d. they are generating these dual wavelengths - beam SW and LW, as radiation beams within band I and band IV respectively.

Description

The present invention relates to the field of interference systems that are used against thermally guided missiles, in general, and more directly with systems and methods known as Direct Anti-IR Measures (the DIRCM) in particular. BACKGROUND OF THE INVENTION

The continued development of white-looking, increasingly lethal and sophisticated heads are relying on the reception of heat radiation emanating from motorized mobile platforms (for example, aircraft, vehicles, armored vehicles, ships, etc.) putting these risks at high risk. means of transport that are exposed to heat-sensitive target search missiles, since all these means are inherent sources of radiated heat.

In response to the formation and development of hazards and the above, interference systems and other systems have been developed and improved, with the aim of interfering and diverting the target-seeking head from its target and diverting it out of its route.

Therefore, for example, some interference systems installed in aircraft against ground-air missiles are known and operate. These systems can detect and locate in real time the launch of a missile from the ground, for example, which has a thermal system that continuously scans the soil surface from the air, discovers the thermal signature of a missile that has been launched, and , as the objectives generate a typical IR radiation by themselves, they can be activated against the target search head that is on the way, interfering with means that are destined to divert the missile from its route. For example, flares can be sent from the attacked target, and can be distributed around the attacked target in such a way that it is said that the heat emanating from the target "confuses" the target-seeking head of the approaching missile and causes the Missile made a turn of its original route, which originally led to the heat radiated from the target's engines.

Other examples, well known and recognized, are "directional interference systems", for example, systems that activate a means of directional interference against the missile that is on the way, such as a laser beam or an intense light that aims to disturb the operation of the white-looking head. Such systems are known as Direct Measures Against IR (hereinafter "DIRCM").

DIRCM systems based on pointing a laser beam towards the approaching missile are described, among others, in DE 4402855, in US Patent No. 5,600,434 to Warm et al., And in US Patent No. 6,369. 885 Brown and collaborators. The DIRCM systems known today have many disadvantages that may be the result of the inherent restrictions due to the limitations of platforms, that is, of space, weight, and environmental conditions dictated by the platform on which the system is installed. It should be understood that the system continuously tracks the approaching missile, and should quickly point the radiated beam towards the approaching missile while the platform that houses the beam generating source is moving, and can be located on a platform that may not Be stable or constant. In other words, the DIRCM system is often integrated into a closed structure that may be exposed to probably very unfavorable environmental conditions, which may be far from optimal to successfully carry out the designated mission.

Thus, for example, by integrating a DIRCM system into a platform such as a line aircraft, it may require modifications to the body of the aircraft. For example, such modifications may include the addition of a mobile turret somewhere outside its outer fuselage, such that it is possible to divert it from the side as well as changing its elevation angles to track threatening missiles aimed at the ship. Such a turret, to allow the tracking of the approaching missile, may be subject to disturbances and forces, such as the movement of the ship, including the change of course, blows, vibrations, etc., making the optimal tracking measures quite tedious. , if it can be executed. In addition, accommodation confined in a passenger ship may require a system with limited accommodation requirements, miniature devices and modules, and all this with minimal interference to carry out the original work of the ship: fly safely and efficiently.

The DIRCM systems known today can implement solid-state lasers that require the beam to be transferred from the laser source through mechanical optical cavities (i.e. elbows) with gimbal mirrors. Naturally, such elements are complex and sensitive to shocks and vibrations, so that they can cause the intensity and quality of the beam to be lost.

Therefore, there is a need for a DIRCM system that can provide an easy and convenient installation proposal, on a large number of different mobile platforms, for example aircraft, tanks or ships etc. Such a system may require the ability to exploit free spaces with limited availability and accessibility on transport platforms. In addition, such systems may require dynamic assemblies with modules of minimum weight and volumes that can be moved in multiple directions in order to carry out the required trace of the approaching missile, to allow precise and stabilized tracking of the missile. It may also be required that such a DIRCM system be a robust system designed such that its structure may contain a limited number of modules and components that are sensitive or susceptible to harsh environmental conditions. SUMMARY OF THE INVENTION

The present invention may include features that provide solutions that help alleviate at least the difficulties inherent in the aforementioned DIRCM systems discussed above. This can be achieved, in accordance with some embodiments of the present invention, by implementing a Fiber Laser medium in the DIRCM system.

The use of a fiber laser medium, according to some embodiments of the present invention, may allow improved operating characteristics for the task of tracking and interference. For example, the fiber laser medium can provide high system efficiency while reducing energy losses in the mobile platform on which it is installed, which can facilitate the packing of the system within the limited free space. in the mobile platform that can transport it, it can facilitate the adjustments of the optical components in the routing system of the laser beam, it can avoid exposure to optical problems that in other systems can be the result of movements of the platforms and the consequent vibrations and impacts, may require relatively few optical components compared to existing non-fiber laser systems, and / or may provide a more rigid and stable optical unit and less cooling and electrical power requirements, due to the greater efficiency of the fiber lasers

In one embodiment of the present invention, the fiber laser medium may include a ZBLAN SW fiber laser medium to provide a first wavelength beam; and an LW silica fiber laser that directly pumps an OPO (Optical Parametric Oscillator) arrangement of ZGP (Germanium Zinc Phosphide) to provide a second wavelength beam. In a further embodiment of the present invention, the above-mentioned silica fiber pumped OPO is independent of the polarization of the pump.

In addition, some embodiments of the present application describe additional fiber-based laser means, applicable to the DIRCM system, for example Yb and Er / Yb fiber-based generators of a variety of wavelengths.

In addition, some embodiments of the present application describe a high brightness multispectral collinear source composed of one or more bands of laser radiation produced by the DIRCM fiber laser medium as the interference beam of the system.

Additionally, some embodiments of the present application may provide the implementation of a plurality of interference bands to operate jointly, independently or sequentially with each other. Thus, for example, in a case of a multi-band system, a simultaneous multi-band interference capability or any single-band interference capability can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood and more fully appreciated from the following detailed description, taken in conjunction with the drawings, in which:

Drawing No. 1 illustrates an example of an installation of a DIRCM system in a passenger aircraft, in accordance with some embodiments of the present invention;

Drawing No. 2 is a general illustration of various assemblies that can form a fiber laser medium, in accordance with some embodiments of the present invention;

Drawings No. 3 to No. 6 are schematic illustrations of different packaging configurations of the different components and means mounted on a mobile and rotating turret means, in accordance with some embodiments of the present invention;

Drawing No. 7 presents a block diagram of an implemented fiber laser medium that is compatible with a DIRCM system that can allow the production of a narrow beam of IR multispectral interference; in accordance with some embodiments of the present invention;

Drawing No. 8A is a schematic illustration of assemblies that make up the fiber laser medium described in drawing No. 7;

Drawings Nos. 8B-8D are schematic illustrations of three alternate pulse generators for the injection diodes described in reference to drawing 8A, i.e. fiber laser, solid state laser and microllaser, in accordance with some modalities of the present invention;

Drawing No. 9 is a conceptual diagram illustrating an example of a combiner that can be used to combine the output beams of the fiber laser medium described in drawings 7 and 8, in accordance with some embodiments of the present invention;

Drawing No. 10 is a diagram of an OPO that depends on the polarization of the pump suitable for direct pumping with a fiber laser as described in Drawings Nos. 7 and 8; in accordance with some embodiments of the present invention;

Drawings Nos 11-14 are diagrams describing OPO designs independent of the polarization of the pump, suitable for being directly pumped with a fiber laser as described in Drawings Nos. 7 and 8, according to some modalities of the present invention; each design converts a polarized input pump beam randomly, while treating pump absorption problems differently and the phase relationship between each polarization state;

Drawing No. 15 is a schematic diagram of the wavelength conversion implemented to produce the desired wavelengths; in accordance with some embodiments of the present invention;

Drawings Nos. 16-21 are diagrams each describing schematic designs of additional fiber-based laser media applicable to the DIRCM system, in accordance with some embodiments of the present invention and

Drawing No. 22 is a schematic example of a multispectral beam combiner to produce a multispectral source, in accordance with some embodiments of the present invention.

It will be appreciated that for simplicity and clarity of illustration, the elements shown in the drawings are not necessarily drawn to scale. For example, the dimensions of some of the elements may be exaggerated in relation to other elements for clarity purposes. In addition, where it is considered appropriate, reference numerals between the drawings may be repeated to indicate corresponding or analogous elements through serial views. DETAILED DESCRIPTION OF THE INVENTION

The following description is presented to allow someone ordinarily skilled in the art to develop and use an invention such as that provided in the context of a particular application and its requirements. Different modifications to the modalities described will be evident to those skilled in the art, and the general principles defined here may be applied to other modalities. Therefore, the present invention is not intended to be limited to the particular modalities shown and described, but is in accordance with the broader scope consistent with the principles and new features disclosed herein. In other cases, known methods, procedures and components for not hiding the present invention have not been described in detail.

The phrase "Direct Measures Against IR" or "DIRCM", as used here, may refer to technological variations and / or systems to counteract attacks on mobile platforms, for example, based on IR-based technologies, but without limiting them. For example, a DIRCM system according to some embodiments of the present invention may use visible light or visible laser technologies, or other elements of the electromagnetic spectrum, in addition to IR radiation.

Reference is now made to Drawing No. 1. Drawing No. 1 is an illustration of how to install a Direct Infrared Measurement System (the DIRCM) 10 on a platform that in this case is a passenger aircraft 20, of according to some embodiments of the present invention.

The system 10 may include detection and / or alert means 30. The detection and / or alert means may be used to detect balloons, for example, missiles 35 that may constitute a threat to a mobile platform, for example, a passenger aircraft 20. Detection and / or alert means can be used to generate a balloon threat warning. Such alerts may include data that may allow the calculation of the anticipated direction of the missile's approach to the aircraft, optionally in real time.

The detection and alert means 30 may include at least part of a "Missile Alert System" (MWS), as is known to a skilled art professional. A MWS type system can be based on the use of different sensors such as those of the IR, UV, or radar type, or any combination of sensors of these types.

In addition, the system 10 may include acquisition means 40. The acquisition means serve to perceive and detect missiles 35 in accordance with the data supplied by the detection and alert means 30. The data received from the acquisition means 40 may allow the system to calculate the updated position of the approaching missile 35, optionally in real time.

Any professional skilled in the art would understand that the acquisition means 40 can be based on the explosion of a FLIR device.

In accordance with the present invention, a laser medium 50 may be a type of fiber laser, as described below with reference to Drawing No. 2. The laser medium may employ visible and / or non-visible light energy. A laser medium 50 may include all the elements that can be used to generate laser energy and transfer the laser energy to the turret 60. In other embodiments, a pump laser may be outside the turret and the wavelength converted. It can be on or in the turret. In other embodiments, one or more elements of the laser medium 50, or other combinations of elements, may be outside the turret.

In addition to the components described above, the system 10 may include a mobile turret 60 that can be pointed and directed as required. This turret means 60 can be coupled with the fiber laser means 50 to direct the laser beam 70 towards the missile 35 that approaches when establishing an observation line with the missile. This would be achieved according to the updated position of the missile 35 which can be calculated using the data that was sent from the acquisition means 40. An example of a field of view of a camera connected to the turret 60 is indicated by lines 45 and 46. Other fields of vision may be used.

Any professional skilled in the art would understand that the laser beam 70 that is generated by means of the fiber laser 50 and that is directed, in its capacity as an interference beam towards the missile 35, can be (if preferred) a narrow beam of multispectral IR (high brightness). One modality of a possible configuration of a fiber laser that is capable of generating a narrow beam of suitable multispectral IR is described below, when referring to the details of Drawings numbers 7 and 8.

The processor means 80 can be coupled - in order to control the system and carry out the data processing - to one or more of the following components: detection and alarm means 30, acquisition means 40, fiber laser medium 50, and turret half 60.

The use of a fiber laser medium can allow the positioning of the laser generator assembly 52 (described below) in one or more locations, while routing the beam at a selected distance (as marked by the letter "L "In the drawing) using an arrangement of one or more flexible fibers 54 towards the turret 60. This can be achieved without having to be subject to a significant loss of energy or a significant deterioration of the beam quality associated with free propagation. in the space.

Any professional trained in the field would understand that the system enshrined in accordance with the present invention is not restricted solely and exclusively to being implemented on a platform that is a passenger aircraft or even any other type of aircraft, but rather - even of in accordance with the present invention - it can be installed on any other mobile platform - such as a vehicle, a tank, or a ship, where it is capable of dealing with other and different types of missiles of "heat white finders", where Heat refers to any wavelength longer than visible light (700 nm). For example, the system can be installed in a tank where it can be used to transmit interference beams against anti-tank land missiles, or target search weapons fired at the tank from the air, etc.

Also, any professional trained in this field would understand that the DIRCM system can be mounted on a platform at the same time assigned to interfere with a thermally guided ammunition that approaches another neighboring platform also in its vicinity.

In other embodiments of the present invention, all or part of the components of the DIRCM system can be implemented within a single unit, such as within a turret means 60.

Reference is now made to Drawing No. 2. Drawing No. 2 is an illustration of the various assemblies of the fiber laser medium 210 according to some embodiments of the present invention.

As mentioned above, an example of a possible configuration of a fiber laser medium that generates, according to an embodiment of the present invention, a multispectral IR beam. This will be described below with reference to the details of the numbers in Drawings 7 and 8.

The fiber laser medium 210 may include a laser generator 220, which may include an electro-optical assembly with one or more fiber laser devices, as well as electronic components (called "electronic means") and cooling medium. The selection of a fiber laser implementation can allow the freedom to position the laser generator outside the free-moving turret. (See component 60 in Drawing No. 1). A typical laser generator, for example, can weigh approximately 40 kg and may require an area of approximately 450 square mm, so any professional skilled in the art would realize that substantial relief of the requirements is achieved, particularly from the point of view. in view of the precision of the tracking movement and essential stabilization aspects related to the movement and directions of the turret.

The fiber laser means 210 can also include an arrangement of either a plurality of flexible or individual fibers 230. As stated, using optical fiber as a means to route the link energy supplied by the generator 220, the ability to supply energy over quite long distances without exposing the system to unfavorable losses of energy while maintaining the high quality of the laser beam. Such an ability to preserve energy is not present when energy is routed through a system of lenses, mirrors, and / or other optical elements due to the losses inherent in each element and on different surfaces. In addition, such a lens and / or mirror system imposes severe requirements related to the necessary accuracy when adjusting and directing the beam, which is further impeded by obstructions resulting from vibration, shock, particles in the system air and other influences. environmental.

The fiber laser means 210 may include a laser head unit 240 linked to the fiber array 230. The laser head unit 240 may include a wavelength converter and an optical subassembly (not shown). The laser head unit 240 can be a compact unit both in its dimensions and in its light weight. A typical laser head unit can weigh as little as about 1.5 kg, and its packaging requires a relatively small box or cabinet, supplied by, for example, a rectangular box whose sides are only 150 x 150 x 100 mm. The laser head unit 240 may be included in or on the turret 60, or it may be outside the turret 60. Therefore, with features such as those described above, any professional skilled in the art would realize, that for implementations such as those described in the present invention, a fiber-type laser can provide inherent advantages compared to the solid-state laser, including greater efficiency (a factor of 2 to 3), stability and robustness in construction (due to to a construction based on a fiber and not an arrangement of mirrors and lenses), the convenience of its packaging and its location in given limited spaces, simple cooling systems, high reliability and direct improvement and options for updating its wavelengths , power, and transmission modes.

The implementation of the fiber laser in DIRCM systems provides better flexibility in terms of the required interference power. A DIRCM system integrated to the fiber laser is, by definition, capable of providing higher output power levels compared to known DIRCM systems, which are based on solid-state lasers for a given electrical power, size and weight. The inherent flexibility imparted by the fiber laser does not require substantial changes in the overall architecture of the system in order to obtain considerable output energy, thereby providing the DIRCM system with a wide variety of means to cause the approach of thermally guided ammunition do not hit your target.

The fiber lasers used, in accordance with some embodiments of the present invention, may include fiber-based combiners. In other embodiments, bulk elements may be used. In additional embodiments a combination of fiber combiners and bulk elements can be used.

A fiber laser medium 210 may include one or more types of fiber, including, for example, CorActive’s Chalogenide fiber (see: www.coractive.com/pdf/IRT_Fiber_General.pdf). In other embodiments, dopings of Tb, Dy and / or Pr can be used to generate, for example, a radiation of 3-5 um directly without an OPO.

Reference is now made to Drawings No. 3 to No. 6. These Drawings present, by means of a schematic sketch, various packaging configurations of the different means that can be installed in the mobile turret means 60 of system 10, of according to some embodiments of the present invention.

Any professional skilled in the art would understand that the turret means required for this system, namely, a mobile turret that can also be directed at will in desired directions, must provide a very fast and accurate response pointing to the approaching missile. A gimbal turret would provide the required characteristics such as those used in observation and surveillance systems, but with much greater dynamics. As a general rule, reducing the weight and volume of the components that are mounted on the rotating part of the turret greatly facilitates - from an optical - mechanical point of view - the task of directing and stabilizing the turret quickly and accurate.

Therefore, any skilled professional in the art would realize that the suggested use of fiber optic elements incorporated in the system implemented in accordance with the present invention, employing namely a fiber laser that in any configuration of the system according With the present invention, it is possible to position the heaviest and most voluminous part of the laser medium, which is the laser generator, outside the component that can rotate from the turret means and even at a certain distance from it (where it is possible to transfer energy from a distant generator towards the turret and the laser head through an array of fibers). Reducing the weight and minimizing the size of the mobile elements that are inside the turret's movable means, an expandable / retractable type of turret means can be obtained that can be hidden while the platform is not under threat.

A configuration design of a turret means 310 is presented in Drawing No. 3. This describes a configuration of separate optical openings, wherein the laser head is located in the fixed (static) base 320.

According to this configuration, a laser head unit 330, which is attached to a fiber array (not illustrated), can be located in the static base 320 of the turret 60. An optical mirror means 350 can be mounted on the rotating component 340 of the turret. The optical mirror 350 can cause a deflection of the laser beam 360 towards a main mirror means 370, located on the rotating component (in its other axes) 380 of the turret. The means of the main mirror 370 may constitute the first optical aperture 382, which can direct the laser beam towards the approaching missile. The other optical aperture 384, can be placed parallel and adjacent to the first optical aperture 382, on the same rotating component 380, and can fulfill the function of acquiring the system (in the illustrated example - based on a FLIR 390 camera ).

An additional configuration design option of turret means 410 is presented in Drawing No. 4. This design has a joint configuration of optical aperture, where both the laser head and the acquisition means can be located in the fixed base (static) of the turret.

According to this configuration, the following is located on the static base 420 of the turret: the laser head unit 430 (which is attached to the array of fibers that is not illustrated); the system acquisition means (in the example illustrated - a FLIR camera 440) and a mirror system 450 that can be coupled to both. An optical mirror means 470 can be positioned in the rotating component 460 of the turret, this lens - from the optical aspect - is coupled with the mirror system 450 and with the medium of the main mirror 480 which can be located in the rotating component (on its other axes) 490 of the turret. The middle of the main mirror 480 constitutes the common optical aperture - and the only one - in this configuration. The laser beam 492 can emanate from the laser head unit 430, and can be driven towards the middle of the main mirror 480 on the same optical axis 494, on which the optical images received by means of the main mirror 480 are led in the opposite direction, towards the FLIR 440 camera. Thus, for example, the optical images are transferred in a ring-like pattern (circular) while the laser beam 494 may be in the center. Any professional skilled in the art would understand that it is also possible to direct the action of the FLIR 440 camera in synchronization with the operation of the laser, with the purpose of preventing mutual glare.

Even another example of a possible design configuration of a turret means 510 is presented in drawing No. 5. In this example, a configuration of separate optical openings is presented where both the laser head and the acquisition means are mounted on the turret turntable component.

According to this configuration, the fiber arrangement 530 can emanate from the static component 520 of the turret, and can extend outwardly and propagate within the rotatable components 540 and 550 of the turret. Obviously in this configuration, the flexible nature of the fibers can be used to drive the laser beam into the turret means and towards the middle of the laser head 560. The acquisition means, in the illustrated example of a FLIR 570 camera they can also be mounted on the component that can be turned 550 of the turret side by side with the laser head 560.

The laser generator 580 may be located at some distance, while the array of fibers 530 may route to the laser beam (one or more) emanating there, all the way to the turret half 510.

A possible approach to exploit the inherent flexibility provided by the fibers in order to overcome the relative movement that takes place between the subassemblies of the turret means is described in Drawing No. 5. Fiber rotating drums 590 and 592 can be mounted in each of the rotation axes 510 of the turret. The winding of the fiber in a shape that looks like a flat spiral structure, as presented in the drawing, can allow the fiber to overcome the stress that tends to be exerted by the relative movement of the turret subassemblies. In other embodiments, fiber optic rotary joints (FORJ), which are as known in the art, can be used instead of or in addition to 590 and 592 fiber roller drums.

An additional design configuration option of a turret means 610 is presented in Drawing No. 6, which may be similar to the configuration described in Drawing No. 4, namely a common optical aperture 620 and wherein both the Laser head 630 as the acquisition medium (FLIR 640 camera in this drawing) can be located on the static (fixed) base 650 of the turret. Additionally, in this FLIR wide-field vision type 670 camera design, the constituent part of the sensor chamber of the detection and warning means of the described system is packed on the rotating component 660.

Reference is now made to Drawing No. 7. This drawing presents an example, at the block diagram level, of a 710 fiber laser medium that may be suitable to be implemented in the DIRCM system, in accordance with some modalities of the present invention, to allow the generation of a narrow multispectral IR interference beam 720. In the illustrated example, the beam 720 may emanate from a source of a fiber laser medium that may constitute a dual wavelength source of power High average, high brightness. In the illustrated example, the beam 720 may be composed of a pulsed radiation beam 715, for example, in the band I and a pulsed radiation 716, for example, in the band IV. Any professional in the art would understand that the beam can be composed of different wavelengths. In addition, any professional in the art would understand that bands I, II, and IV can be operated together, independently or sequentially with each other. Thus, for example, in the case of a dual band system, the interference capacity of a simultaneous dual band or any interference capacity of an individual band may be allowed.

In addition, any professional in the art would realize that a DIRCM system according to the present invention can utilize multi-band capabilities and therefore provide simultaneous multi-band interference capability or any individual band capacity.

An optical telescope 730 (which constitutes a part of the laser head unit, see for example, above where Drawing No. 2 refers to the laser head unit 240) can integrate the two beams in such a way that the beam becomes collinear. Both wavelengths can be emitted simultaneously by the same path of beam 722.

In the illustrated example, the pulsed radiation beam in the I band can be generated using a short wavelength ZBLAN device that is a 740 fiber laser medium. This item is a fiber laser that can be based on a glass " exotic ”that is endowed with a high transmittance capacity in the broadband spectrum while attenuating minimal amounts of light.

The pulsed radiation beam component in the IV band can be generated using a ZGP 750 device pumped from the fiber laser that includes a 755 fiber laser device of the long wavelength silica fiber laser type and an Optical Parametric Oscillator (OPO) Germanium Phosphide - 757 non-linear crystalline zinc which is directly coupled to it.

Any skilled professional in the art would understand that using the ZGP OPO imparts high conversion efficiency that can be used for low energy pulses and has excellent thermal properties that allow use with high average power. It should also be noted that in this specific modality, ZPG was selected due to its high non-linear gain, good thermal and mechanical properties, and a relatively high damage threshold. Other non-linear crystals can be used: gallium and silver selenide (AGSE), optically stamped gallium arsenide, periodically polarized lithium niobate or lithiumlate that can be doped with magnesium oxide or in stoichiometric form, silver thiogalate (AGS) , etc.

Reference is now made to Drawing No. 8A. As mentioned above, Drawing No. 8A constitutes a schematic sketch of the assemblies for making the fiber laser medium 710 that is described in Drawing No. 7, namely the components of the ZBLAN 740 fiber laser medium and the ZGP OPO 750 pumped silica fiber laser.

The ZBLAN 740 fiber laser medium can include a single fiber laser without a diode injection, which can be modulated by the pump diodes. Such fiber medium can be implemented using Tm / Ho: ZBLAN.

In other embodiments, the ZBLAN 740 fiber laser medium may include an injection diode 810 that is positioned at the end of a fiber 820, which may or may not contain a Bragg grid fiber. Diode 810 and fiber 820 can set the pulse rate, pulse duration, and wavelength.

The fiber 820 can be attached to the first beam combiner 830. The first beam combiner 830 can be coupled - using a high power pumped light filter 835 - with the first pump diode 840.

The first beam combiner 830 may include collimation lenses 831A at the combiner inlet. The protective element of the pump diode 832 can be positioned at the entrance of the high power pumped light filter 835. The dichroic mirror 833 can combine the beams and route them through a double lens of fiber coated 834 to a double fiber coated ZBLAN 850. ZBLAN 850 double coated fiber can be interconnected between the first fiber beam combiner 830 and a second beam combiner 860 and constitutes the lasing material.

The second beam combiner 860 can be connected using a high power pumped light fiber 865 to the second pump diode 870. The second beam combiner 860 can include a double fiber coated lens 864 to the combiner inlet. The second protective element of the pump diode 862 can be located at the entrance of the high power pumped light fiber 865. The dichroic mirror 863 can combine the beams and route them through an output lens 864 to the output fiber or , in other words, to the 880 conveyor fiber.

The 880 conveyor fiber can connect the second beam combiner 860 to the collimator

890. The 891 pulsed wave radiation in band I, which was discussed above, can actually come from collimator 890.

The specific means of the ZBLAN fiber laser illustrated as the example in the drawing, can include two beam combiner assemblies (830 and 860, respectively), which can be connected, each separately, with pump diodes 840 and 870 respectively. Any professional in this field would understand that according to the required power, the ZBLAN fiber laser medium can be composed of a greater number of series combiners (of those that exist in the arrangement illustrated).

The ZGP 750 OPO pumped from silica fiber laser can include a 755 long wavelength silica fiber laser device and a ZGP 757 Optical Parametric Oscillator (OPO) that silica fiber laser pumps.

A prominent feature that distinguishes this described example is the fact that a silica-type laser can directly pump the OPG from ZGP. Any skilled professional in the art would realize that direct pumping of the ZGP OPO by the silica-type laser from OPO generally requires polarized light, on which the fiber may or may not be, and that the direct pumping of an OPO for a pulsed fiber laser, which is not common since the intensity of the pulsed peak is generally small. In some modes, non-polarized light can be used.

Silica fiber laser 755 may include an injection diode 910 that is connected to a fiber 915, which may or may not contain a Bragg fiber grid. Diode 910 and fiber 915 can set the pulse rate, pulse duration and pulse wavelength. The fiber 915 in turn can be connected to a first beam combiner 920. The first beam combiner 920 can be connected to a pump diode 925 through a high-power pumped light fiber 930. A double silica coated fiber 935, which amplifies the laser signal produced by 910 and 915, can interconnect the first beam combiner 920 with the second beam combiner

940. The second beam combiner 940 can be connected to a pump diode 945 through a high power pumped light fiber 950. The beam combiners 920 and 940 can provide a method for pumping the laser amplifier 935 with the laser diodes 925 and 945. A transport fiber 955 can route the beam to a third beam combiner 960. A third beam combiner 960 can be connected to a pump diode 965 through a 970 high power pumped light fiber. double coated with silica 975, which can act as the second laser amplifier, interconnects the third beam combiner 960 with the fourth beam combiner

980. The beam combiners 960 and 980 can provide a method of pumping the laser amplifier 975 with the laser diodes 985 and 965. The fourth beam combiner 980 can be connected to a pump diode 985 through a pumped light fiber of high power 990. A transport fiber 992 can route the beam to an output collimator 993, and therefore to the OPG of ZGP 757.

A cooling assembly 995 can perform the required cooling of all pump diodes in the system, fibers, ZGP, and / or mechanical assembly, and assembly of electronic components. An assembly of electronic components 997 can control the operation of the entire system.

The specific means of the silica fiber laser that are illustrated in the drawings may include four beam combiner assemblies that are interconnected, each with the respective pump diode. Any professional skilled in the art in this field would understand that, according to the required power, the silica fiber laser medium can be composed of a large number of combiner-pump pairs connected in series, or alternatively, only of a single pair.

So far we have presented an option, namely a 910 and 810 laser injection diode in Drawing 8A, to generate the power pulses necessary to pump the wavelength converter. Such injection diodes can be either expensive and / or difficult to manufacture.

There are currently three other options to generate pulses. They are a fiber laser, a solid state laser, and a micro laser. Pulse lasers can be pulsed either by modulating the laser pump, by lighting passively or actively at Q, or actively or actively in locked mode.

Reference is now made to Drawing No. 8B. Drawing 8B shows an example of an 8110 fiber laser oscillator actively turned on in Q that may be able to generate short pulses. The cavity 8120 may include a Bragg Fiber Grid (FBG) 8130 that can serve as a final mirror and select the wavelength. The FBG 8130 can be connected to the switch Q 8140 through a fiber 8150. The switch Q 8140 can actively or passively modulate the loss in the cavity 8120 to cause a pulse. The Q 8140 switch can be of many technologies, including a saturable absorber, an electro-optical switch, or an optical acoustic switch. In the world of optical fiber, active devices, referred to as intensity modulators and / or EO modulators, can be optical components integrated on a lithium niobate substrate. Switch Q 8140 may be attached to a fiber 8160 that can be entered by a beam combiner 8170, as previously described with reference to drawing 8A. Lasing 8180 fiber may be located after the 8170 beam combiner. In other embodiments, a Bragg Fiber Grid (FBG) may be used instead of a second final mirror. The surface 8185 next to the beam combiner 8170 may have an angle polish to avoid lasing this surface. The other end 8187 of the lasing 8180 fiber may have a zero-grade surface that acts as the other final mirror and the output coupler of the Frensel transmission. This particular example may use an active QS 8140. Such a switch Q may preferably be made of BBO or RTP to support high repetition rates. In addition, fiber lasers in locked mode can also provide very high repetition rate laser sources (> 1 MHz). The laser can be either single polarization or random polarization.

Reference is now made to Drawing No. 8C. Drawing 8C shows an example of a 8210 solid state laser that can be used to sow a 8220 fiber amplifier. Only short pulses of low energy may be needed, so that only thermal problems typically encountered with lasers can be avoided. solid state The 8225 cavity can include two mirrors - 8230 and 8240 (also marked as M1 and M2), which can be flat or curved to support the fundamental Gaussian mode. Mirror 8240 can also be the output coupler. In this example, the lasing 8250 is a Brewster cut to ensure a minimum loss due to reflection and a unique polarization operation. However, this laser can also be in a random polarization. The cavity 8225 also contains a Q (QS) 8260 switch, which can be either of the active or passive type. If an active switch Q is used, it can be either acoustic - optical or electro - optical. If an electro-optical switch, RTP or BBO is used, it is the choice crystal due to the high repetition rates required. The lasing medium 8250 can be pumped through the mirror 8230 by a pump diode (PD) 8270, which can be connected to the combiner 8275. The size mode of the pump diode 8270 and the laser cavity 8225 can match to ensure high conversion . The output of the laser cavity 8225 can be coupled to the fiber 8220 through the 8280 lens.

Reference is now made to Drawing No. 8D. Drawing 8D shows a passively switched on laser in Q 8310 capable of serving as the laser oscillator in a DIRCM system. An advantage of a microllaser is that the cavity 8320 can be a monolithic block of material. Lasing medium 8325 can be pumped through a dichroic final mirror 8330 (also marked M1), by a pump diode (PD) 8335 that can be connected to combiner 8340. Cavity 8320 can include a dichroic final mirror 8330 that can Transmit the pump but reflects lasing radiation. The radiation from the pump can reverse the lasing 8325 medium. The fluorescence of the lasing 8325 medium can eventually saturate a passive switch Q (QS) 8350 and cause it to open. The cavity 8320 can then lase between the mirror 8330 and the mirror 8360 (also marked as M2), which is the output coupler. The beam 8365 can then be directed on a fiber 8370 by means of a lens 8380. The fiber 8370 can then be directed to the fiber amplifiers (not shown). This laser can be either single or random polarization.

Reference is now made to Drawing No. 9. It is a conceptual diagram illustrating an example of an applicable combiner 1009 for combining the output beams of the fiber laser medium, described in Drawings 7 and 8, to be collinear. Such a combiner can be packed as part of the telescope's medium (see Drawing 7, item 730), and integrated as part of the laser head unit (see Drawing 2, item 240). In the example described in the drawing, an optical array 1011 can combine at least two laser beams 1013 and 1015 that may have arrived from the ZGP OPO pumped from the silica fiber laser and the ZBLAN fiber laser, and can spend them through the spent lens lenses 1017, and collimate the beams through collimating lenses 1019, with the purpose of combining them in a collimated beam 1021 that can be directed towards the thermally guided approaching threat.

Any skilled professional in the art will understand that the combiner 1009 is just an example and that other optical arrangements (using, for example, mirrors) can be implemented to combine the outgoing beams to be collinear.

The at least two types of optical parametric oscillators (OPOs) can be used in a DIRCM system according to the present invention - the polarization dependent and polarization independent OPOs, where "polarization" refers to the pump beam.

With reference to Drawing No. 10. The drawing constitutes a diagram of an OPO independent of the polarization of the pump 1010 suitable for being directly pumped with fiber laser as described in Drawings 7 and 8. The modalities use two OPOs dependent on 1015 and 1020 polarization directly pumped, according to the present invention, with a fiber laser medium.

The beam of the input pump 1025 (also marked λp) can be divided into two linear polarization states, 1027 and 1029, by means of a polarization hub or a thin film polarizer 1030. A polarization state of the pump , called 1027 (also referred to as "P" in the drawing), the cavity of the OPO 1015 can enter through a dichroic mirror 1031 (also referred to as "M1" in the drawing). The pump can then enter non-linear glass 1033, in this mode ZGP (germanium and zinc phosphide) which is oriented and cut in such a way that it converts the pump beam 1027 into the desired signal and vague beams 1035 and 1040 (called also as λS, λI). In this case, the signal and vague beams 1035, 1040 can have the same polarization, which can be orthogonal to the pump beam.

The pump beam can then be reflected from the mirror 1042 (also referred to as "M2" in the drawing), for a second passage through the glass 1033. The signal 1035 and the vague signal 1040 can resonate in the cavity 1015 and some of the signals and the vague signal can be filtered through 1042 (in this case 50%) to leave the cavity 1015.

The second state of polarization of the pump beam 1025, referred to as 1029, can be guided by means of guide mirrors 1045 to enter a second OPO 1020 (in this mode, both OPOs can use the same mirrors but different crystals) through of the mirror 1031. The non-linear conversion can occur in the non-linear glass 1050, which can be oriented and cut in such a way that this state of polarization is converted.

The outputs of both OPOs, 1033 and 1050, can have different polarizations. The output of the OPO 1033 can be guided by means of the steering mirror 1055, and these signal and vague signal beams (λS, λI) can be combined using a polarization cube or a thin film polarizer 1060 to obtain a single beam 1070

Any professional skilled in the art will realize that this design has a very high conversion efficiency (> 60%) since the pump beam passes through the glass twice.

Reference is now made to Drawings 11-14. The drawings are diagrams each describing the design of the independent pump polarization OPO suitable for being directly pumped with a fiber laser as described in Drawings Nos. 7 and 8 Each design (1110, 1210, 1310 and 1410), can convert a polarized input pump beam randomly, while treating the pump absorption problems and the phase relationship between each polarization state differently.

The OPO design 1110 shown in Drawing 11 can use a random polarization input pump beam 1115 (also referred to as λp). The beam of the pump 1115 can enter the mirror 1120 (also referred to as M1). Both linear polarization states can enter the first crystal 1125. Only a polarization state of the pump (marked "P") can be converted into this crystal. The pump can then enter the second crystal 1130 which converts the second state of polarization of the pump (marked "S"). The pump can then be reflected back by the mirror 1135 (also referred to as M2) for a second passage through each crystal 1130 and 1125. The signal and the vague signal (λS, λI) generated in the crystal 1125 can have the same polarizations, which can be orthogonal to the polarizations of the signal beam and the vague signal (λS, λI) generated in the crystal 1130, which also have the same polarizations. For this reason, the nonlinear processes for each polarization of the pump beam can be presented in separate crystals, since they can be independent. The output polarization 1140 of this OPO can be random like the pump.

Any professional trained in the art will realize that this OPO design has a minimum number of parts to align. It can consist of, for example, only two crystals, 1125 and 1130 and two mirrors, 1120 and 1135. Non-linear conversion processes for each state of polarization can occur independently in different crystals, and the design can be capable of handling both energies Low as high pulse. However, if the crystals absorb the pump, the conversion may lose efficiency due to the absorption of the pump: the pump must pass through a glass before being converted. The polarization "S" must pass through the crystal 1125, in which part of the energy can be absorbed, before being converted into the crystal 1130.

With reference to modality 1210 described in Drawing No. 12, it should be appreciated that this modality requires only a non-linear crystal, where the crystal tends to be a rather expensive element in the OPO system.

The beam of the pump 1220 may be incident on a dichroic mirror 1225 (also referred to as "M3") that reflects the beam within the OPO 1230. The beam of the pump may enter the mirror 1235 ("M1"). A state of polarization of the pump can be converted into non-linear glass 1240. The other polarization passes through crystal 1240, although some of it is absorbed. The pump can then pass through a quarter wave plate 1245 and can be reflected outside the mirror 1250 ("M2"). After passing through a 1245 quarter wave plate again, the pump can now have an orthogonal polarization state that can generate the vague and signal beams. The vague and signal beams resonate in cavity 1260, and are coupled outside at 1235 (M1). Mirror 1225 (M3) can pass the signal and vague signal beams 1270 (λS, λI) and reflect the pump.

There can be multiple modalities of the wave plate of a room 1245. A first mode can be of a wave plate of a room only for the pump. The signal and vague signals are not specified. The signal and vague signals may rotate at non-specific angles, which may tend to decrease efficiency since the phases may not be aligned with the pump.

A second mode may be a quarter wave plate for the pump and the vague signal. This is the same case of two independent OPOs with a single-pass pump beam. This design may be more suitable for high energy pulses that may only require a passage through the glass to experience high conversion efficiency. The quarter wave plate can be replaced with a periscope or a cabin compensator if the OPO is a ring cavity. These elements make a half wave rotation.

A third mode may be a quarter-wave plate for the pump, and a half-wave plate (any integer multiple) for the signal and the vague signal. In this case, the polarization of the pump can be rotated 90 degrees on each round trip, and the polarizations of the signal and the vague signal may not be rotated. In this way, the different polarization states of the pump can amplify the same polarization states of the signal and the vague signal.

As mentioned above, any professional trained in the art will realize the fact that this EPO is relatively simple to align and contains only one crystal.

  Reference is now made to Drawing No. 13. In this mode, OPO 1310 uses the different polarizations of the pump to amplify the same signal and the vague signal. The beam of the pump 1320 may be incident on a dichroic mirror 1330 ("M3") that may reflect the beam within the OPO 1310. The beam of the pump 1320 may enter the mirror 1340 ("M1"). A state of polarization of the pump becomes within the non-linear crystal 1350. The other polarization can pass through the crystal, although some of it can be absorbed. The pump can then pass through mirror 1360 ("M4"). The signal and the vague signal can be reflected from this mirror. The pump can then pass through the quarter wave plate 1370 and can be reflected from mirror 1380 ("M2"). After passing through the wave plate of a quarter 1370 again, the pump can now have an orthogonal polarization state that can generate the signal and vague signal beams. The signal and vague signal beams can be resonated in the cavity 1385 with final mirrors 1340 and 1360 (between "M1" and "M2"), and can be coupled outside in 1340 ("M1"). The dichroic mirror 1330 ("M3") can pass the signal and vague signal beams 1390 and can reflect the pump.

Any professional skilled in the art will understand that this design uses a single nonlinear crystal and both states of polarization of the pump are used. In addition, since each polarization passes only once through the crystal, this design is more suitable for high energy pulses.

Reference is now made to the mode described in Drawing No. 14. In this mode, an individual OPO 1410 can be pumped twice for each polarization of the pump. The pump beam 1420 (λp) can only pass through the crystal 1430 when it is capable of amplifying the signal beam and the vague signal. In addition, the output beams 1440 (λS, λI) can be polarized with the same polarization state.

The pump beam 1420 (λp) can enter a polarization hub or a thin film polarizer 1445 to divide the polarizations. A polarization 1450 can enter the cavity of the OPO 1411 through the mirror 1455 (M1). The second polarization of the pump 1451 can be reflected from a steering mirror 1460 and can then pass through a half-wave plate 1465, which can rotate the polarization to the other state. The beam 1451 can then enter the cavity of the OPO 1411 through the mirror 1470. In this way, the OPO 1410 can be pumped through the same state of polarization in the upper and lower arms, 1412 and 1413, between the mirrors 1455 and 1475 and between mirrors 1470 and 1480 respectively. The pump in each arm (M1-M2 and M1-M3) can make two passes through the individual nonlinear glass 1430. The signal and the vague signal 1485 are coupled outside the cavity in the mirror 1475.

Any professional trained in the art will realize that according to this modality, each beam of the pump passes twice through the glass giving more amplification passes. This is especially suitable for low energy pulses.

With reference to Drawing No. 15. The drawing is the general scheme of wavelength conversion 1510 implemented to produce the desired wavelengths. A fiber laser medium 1511 can be used to produce a wavelength 1513. This wavelength 1513 can drive a wavelength converter 1512 that can produce a single or multispectral output 1514.

The fiber laser medium can be an Er / Yb: silica fiber, Yb: silica fiber, Tm: silica, Tm / Ho: silica fiber, Tm: ZBLAN or Tm / Ho fiber: ZBLAN or any combination thereof (Anyone skilled in the art would understand the use of Yb / Ho: silica and Yb / Ho: ZBLAN for all places where Tm / Ho: ZBLAN is mentioned). The fibers can be independent of polarization, which maintain polarization, or large mode area.

The wavelength converter 1512 may consist only of an optical parametric oscillator (OPO) as described above with reference to Drawings Nos. 10-14, a single cavity of the OPO with one or more crystals that can produce multiple lengths of wave, top converters, such as a converter to generate the second harmonic, top converter lasers such as Tm: ZBLAN that is pumped by a Yb fiber laser: silica, a frequency converter using Raman amplification or four wave mix, generator Parametric optical (OPG) and an optical parametric amplifier (OPA), and OPO and an OPA, or a serial OPA or OPO via another source, such as a laser diode (not shown). In addition, each of these converters can be connected in series to obtain the final wavelength. The non-linear crystal used in the wavelength converter can be a polarized crystal with transparency at a predefined wavelength, such as PPLN or PPLT possible in stoichiometric forms with or without MgO doping, or birefringent crystals such as AGS or AGSE .

In some embodiments of the present invention, a bulk laser can be used to convert the generated wavelength. Since high power laser diodes are not available at all wavelengths, a fiber laser can be used to convert the energy of the laser diode pump into pump energy to another wavelength that a laser material can use different. In modalities where fiber laser is used as the pump source, bulk laser pumped from fiber laser can be used, for example the Tm: silica fiber laser, for pumping, for example Ho: YAG, Ho: YLF, Ho : YA103, to achieve either a SW or LW source either independently or with the use of another wavelength converter. For example according to some modalities, silica fiber: Tm can be used to pump a bulk laser that can be used to pump an OPG from ZGP. In some embodiments, a fiber laser can be used to pump a holmium doped material to achieve either a SW or LW source, either independently or with the use of at least one wavelength converter.

Reference is now made to Drawings Nos. 16-21. The drawings are diagrams that each describe the design of additional fiber-based laser media, applicable to the DIRCM system.

Reference is now made to Drawing No. 16, which is a schematic illustration of a modality of a dual OPO 1610 glass pumped from Yb: silica fiber. Yb: silica fiber diode pumped lasers are mature technology with high overall efficiency. Recent advances have made it possible to produce an individual linear polarization from these lasers, which is ideal for pumping an OPO. One possible way to convert light with a wavelength to a second wavelength is shown in Drawing No. 16. In this case, a Yb: silica fiber laser (not shown) is used to pump a PPLN OPO ( periodically polarized lithium niobate) 1610 to generate the desired wavelengths. The pump beam can be incident on the mirror 1620 (also marked M1), which can fully transmit the pump and reflect all wavelengths generated within the cavity 1630. In the first crystal 1640, the length can be converted of the first wavelength band pump wave in a second wavelength band (for example, 1µm for band I). The second crystal 1650 may have the appropriate polarization period to convert the second wavelength to a third wavelength (for example from band I to band IV). The pump beam can then be fully reflected by mirror 1660 (also defined as M2). The mirror 1660 can act as an output coupler for the desired output wavelengths 1670 (also marked as λ1, λ2, λ3). The intermediate conversion of the first wavelength to the second wavelength (for example, 1µm for band I), can increase the total efficiency of light conversion (for example, 1µm for band IV). In addition, many and any of the wavelengths can be generated in the bands of interest simultaneously with this design (for example, band I, band II and band IV, in any combination). In addition, a random polarization pump laser beam can be used with similar OPO designs shown previously in this disclosure.

Reference is now made to Drawing No. 17. Drawing No. 17 is a schematic illustration of OPO 1710 dual pumped glass fiber of Er / Yb: silica. Er / Yb: silica fiber lasers are also a mature technology. These lasers can produce wavelengths centered on a predefined wavelength (for example, about 1.56 µm). In certain applications, since the wavelength is closer to the required band (for example, band II, band IV), than the Yb fiber lasers, this solution may offer a more efficient generation scheme. A converter mode 1720 is shown in Drawing No. 17. In this case, the input beam of the pump 1730 (also referred to as λp) can be produced from an Er / Yb fiber laser: state silica of random polarization (not shown). The pump can enter the cavity of the OPO 1740 through the mirror 1750 (also called M1). The first crystal 1760 can convert a pump light polarization directly to the desired length (for example, of 1.55 µm for the IV band). The second crystal 1770 can be identical to the first crystal 1760 except that it can be rotated 90 degrees around the optical axis 1780 to convert the other polarization of the pump beam. The pump can then be reflected outside the mirror 1790 (also marked as M2). The light (for example, in the band IV) can be partially reflected back in the cavity 1740 and the remaining light can be transmitted through the mirror 1790.

Reference is now made to Drawing No. 18. Drawing No. 18 describes a mode of pumping a Tm / Ho: ZBLAN or Tm: ZBLAN 1810 fiber laser by means of a Yb: silica 1820 fiber laser to produce certain light predefined by superior conversion (anyone skilled in the art would understand the use of Yb / Ho: silica and Yb / Ho: ZBLAN for all the places where Tm / Ho is mentioned: ZBLAN).

In some DIRCM applications there may be a need for Non-Ionizing Radiation (NIR) sources: wavelengths between 700-900 nm. One way to achieve these wavelengths may be to use a higher conversion process that, for example, can occur in Tm / Ho: ZBLAN or Tm: ZBLAN when pumped with certain wavelengths (for example 1064 nm). In the scheme shown in Drawing No. 18, a Yb: silica 1820 fiber pumps a Tm / Ho: ZBLAN or Tm: ZBLAN 1810 fiber laser with a certain 1830 wavelength (for example 1064 nm) designed to lase around a second predefined wavelength 1840 (for example 800 nm). The mirrors (not shown) can be selected in such a way that this wavelength resonates in the 1810 fiber.

Another way to obtain wavelengths in the NIR (for example 700 - 850 nm), is to make a second generation of harmonics from an Er / Yb: silica fiber laser. The general schematic diagram is shown in Drawing No. 19. In this case, the 1910 fiber laser is an Er / Yb fiber laser: silica with either random or specified polarization. The beam 1920 can then enter a 1930 wavelength converter, which in this case can be a PPLN OPO specifically designed for a second generation of 1940 harmonics (for example, 780 nm of 1560 nm).

In some DIRCM applications, there may also be a need to produce visible light sources (for example, 450-650 nm), specifically green and yellow light. The second generation of Yb: silica fiber laser harmonics is ideally suited for this task. The general solution is shown in Drawing No. 20. In this case, the 2010 fiber laser can be a Yb: silica fiber laser with either random or specified polarization. The 2020 beam then enters a 2030 wavelength converter, which in this case could be a PPLN OPO specifically designed to produce a second specific harmonic generation of 2040 light (for example, from 1064 nm to 532 nm).

A third generation of Er / Yb fiber laser harmonics can also be used: silica to produce visible light (for example 500-600 nm). The general idea is shown in Drawing No. 21. In this case, the 2110 fiber laser is an Er / Yb fiber laser: silica with either random or specified polarization. The beam 2120 can then enter a wavelength converter 2130, which in this case can be a PPLN OPO specifically designed to produce a third generation of harmonics 2140 (for example, from 1560 nm to 520 nm).

Reference is now made to Drawing No. 22, which is a schematic example of a multispectral beam combiner implemented to produce a multispectral source. The laser medium described hereinabove in reference to Drawings Nos. 7-14 and the additional potential modalities described herein above in reference to Drawings Nos. 15-21 may be combined to produce a high brightness multispectral source for the beam of interference required. The prior disclosure provided in reference to Drawings Nos. 7-14 showed a solution to combine two beams of different wavelengths: a dichroic mirror was used to reflect a wavelength and to transmit the second to produce a two-color beam . The additional modality described hereinafter expands the capabilities of the DIRCM system designed in accordance with the invention, to include a system output of one to many colors.

One embodiment of a multispectral beam combiner is shown in Drawing No. 22. In this example, four collimated beams 2211, 2212, 2213, and 2214, of different wavelengths can be combined to produce a collinear multispectral beam 2220. The Combiner 2230 may include a sapphire block, or other transparent material for all wavelengths, coated with several mirrors of different properties. Mirror 2240 can be a high reflector for all incident wavelengths. The mirror 2250 can transmit a wavelength 2212 but reflect the wavelength 2211. The mirror 2260 can transmit the length 2213 but reflects the wavelengths 2211 and 2212. The mirror 2270 can transmit the wavelength 2214 but can reflect the wavelengths 2211, 2212 and 2213. As shown in the Drawing, a wavelength can be added for each energy of the beam 2220 outside the mirrors 2250, 2260 and 2270.

Other combustion technologies based on polarization that combine or disperse elements - diffraction gratings, prisms, waveguide arrangements, etc. - may also allow multispectral combinations.

The modalities of the present invention are not restricted to one or another aerial configuration, and, like any professional skilled in the art would understand, modalities can be implemented in any scenario, be it air, sea or land or any combination thereof.

People skilled in the art will realize that the present invention is not limited to what has been particularly shown and described above. Instead, the scope of the present invention is defined only by the claims that follow.

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is solely for the convenience of the reader. It is not part of the European patent document. Although great care has been taken in the collection, errors or omissions cannot be excluded and the EPO rejects any responsibility in this regard.

Patent documents cited in the description

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DE 4402855 [0006] • US 6369885 B, Brown [0006]

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US 5600434 A, Warm [0006]

Claims (10)

1. A system of Direct Measures Against IR, DIRCM (10) comprising: detection means (30) to detect a ship (35) that may pose a threat to a mobile platform (20) to which said system is attached ; alert means (30) to generate an alert when a ship that represents a threat is detected; acquisition means (40) to generate the data acquisition of said approach while calculating an updated position of said ship that constitutes a real-time threat; fiber laser means (50) for generating a laser beam (70); a mobile turret means (60), coupled with said fiber laser means to direct said laser beam towards said ship; processing means (80) that are associated with said detection means, said acquisition means, said fiber laser means and said mobile turret means; characterized in that said fiber laser means

to.

they are generating said laser beam as a narrow beam of SW and LW - dual wavelength, high brightness, average power, suitable for interfering said ship; Y

b.

to provide said SW beam, it is a ZBLAN fiber laser doped with Tm / Ho, a Silica fiber laser doped with Tm or a holmium bulk laser pumped by a silica fiber laser doped with Tm; Y

C.

to provide said LW beam, it is a Periodically Polarized Lithium Niobate, PPLN, or Periodically Polarized Stoichiometric Lithium Tantalite, PPSLT, Optical Parametric Oscillator, OPO, pumped by a Yb-doped silica fiber laser or a Germanium and Zinc Phosphide , ZGP, OPO pumped by a bulk Ho laser pumped by a Tm doped silica fiber laser.

d.

they are generating these dual wavelengths - beam SW and LW, as radiation beams within band I and band IV respectively.

2.

A DIRCM system (10) according to claim 1, wherein said platform (20) to which said system is assigned is selected from the group consisting of an aircraft, vehicle, armored vehicle, tank, or ship.

3.

A DIRCM system (10) according to claim 1, wherein said system can be mounted on said platform (20).

Four.

A DIRCM system (10) according to claim 1, wherein said alert means includes a sensor that is an IR, UV, visible light or radar sensor, or any combination of said sensors.

5.

A DIRCM system (10) according to claim 1, wherein said acquisition means (40) includes a FLIR device (440, 570, 640, 670).

6.

A DIRCM system (10) according to claim 1, wherein said fiber laser means (50) includes a telescope means (730) to form a collimated beam from said SW and LW laser beams.

7.

A DIRCM system (10) according to claim 1, wherein said fiber laser medium (50) includes a holmium doped material which when pumped by said fiber laser means is capable of generating said laser beam SW and LW .

8.

A DIRCM system (10) according to claim 1, wherein said OPO depends on the polarization of the pump.

9.

A DIRCM system (10) according to claim 1, wherein said fiber laser medium

(50) is pulsed and the pulse rate, pulse duration and pulse wavelength are set by at least one injection diode (810, 910) that is connected to a fiber.

10.

A DIRCM system (10) according to claim 1, wherein said fiber laser medium (50) is polarized either simply or randomly.