DE102005034613B3 - Anti-missile defense device, anti-missile defense method and use of a laser device - Google Patents

Abstract

The defence device against missiles (12), with infrared detection (14), comprises a plasma generating unit (16) by which a plasma or plasma breakthrough is generated in the air at a distance from the plasma generating unit. One or more plasma clouds (30) are produced in the air by the plasma generating unit. The plasma generating unit includes at least one laser device (18) by means of which light pulses are emitted. Independent claims are included for: (1) a method for defence against missiles which have infrared detection which entails producing plasma clouds in the air; and (2) a use of a laser device for producing plasma in the air.

Description

The The invention relates to a defense device against missiles to electromagnetic radiation, in particular infrared radiation, responsive target acquisition.

The The invention further relates to a method of defense against missiles, which one on electromagnetic radiation, in particular infrared radiation, have responsive target acquisition.

Missile, like For example, equipped with a warhead missiles or intelligent Ammunition, can have a target detection, which is based on electromagnetic radiation and in particular infrared radiation reacts and can thereby find their destination, such as an airplane. The infrared radiation, which the target acquisition responds to, for example, by engines of the plane.

Out WO 2004/058566 A1 is a method for deflecting a projectile from an initial one Trajectory known, the projectile a first surface area and a second surface area has and is surrounded by a gaseous atmosphere plasma sheath emotional. Electromagnetic radiation is directed to the projectile, wherein the electromagnetic radiation has a frequency passing through the plasma sheath absorbed to a significant degree but not by the gaseous the atmosphere is absorbed.

From the DE 41 07 533 A1 is a method for protecting aircraft from missiles with UV homing heads known in which the aircraft are at least temporarily provided with a UV-emitting radiation source.

From the EP 0 240 819 A2 is a method for deflecting guided by radar and / or infrared radiation missiles are known, are ignited in or before the target area of the missile-generating projectile throwing body.

From the DE 27 44 401 A1 For example, a laser is known, in particular, for projectile and / or target tracking and for illumination purposes, in which a pyrotechnic flare is provided as a pump light source.

In the article "High Energy Petawatt Lasers - The Generation ultraintensive pulses "by Stefan Borneis, Photonik 3/2005, pages 76-79 is a Nd: glass high-energy petawatt laser described.

Of the Invention is based on the object, a defense device of to provide the type mentioned above, by means of which a protection against such missiles is reachable.

These Task is inventively characterized solved, that one Plasma generating device is provided, with which in air a plasma can be generated at a distance from the plasma generating device is.

In Air leaves generate a plasma locally when the plasma breakthrough threshold of Air exceeded will, that is if in a place in the air so high field strengths prevail that the plasma breakthrough he follows. The plasma formation is accompanied by the emission of electromagnetic Waves. In particular, the plasma recombination leads to radiation among others in the infrared range. The missile with target detection, which reacts to electromagnetic waves, can respond to the radiation and be through the target detection the missile directed in the direction of the location of the plasma formation. This in turn he can be protected by one Object being distracted like an airplane. Through the plasma formation in air can be a target deception in the target acquisition of the missile carry out. This allows, for example, flying objects such as aircraft or also protect room areas around an airport. The missiles with electro-optical target acquisition, defined "goals" are provided, to be protected Secure objects.

plasmas in air, for example, can be formed laser-induced. By Ultrashort light pulses, the plasma breakthrough threshold can be achieved in air. Due to the non-linear propagation of ultrashort light pulses in the atmosphere it comes by induced Kerr effect to a self-focusing a laser beam. For This self-focusing is not a telescope necessary, but it is enough a "normal" optics. It is through possible, the corresponding laser device at a great distance (the 10 km or can be more) from the location of the plasma breakthrough, that is the one Plasma breakthrough can be in a big one Distance to the laser device by the self-focusing cause.

In particular, one or more plasma clouds (plasma spheres) can be generated in the air by plasma breakthrough by the plasma generating device. These generated plasma clouds are accompanied by the emission of electromagnetic radiation, to which the target detection of a missile can react. The plasma formation has a defocusing effect on the laser beam. By white tere propagation of the light pulses in air can again take place a self-focusing. It can then form a series of plasma clouds. It can also occur a filamentation, in which a plasma breakthrough takes place in filaments between plasma clouds.

Especially comprises the plasma generating device at least one laser device, by the light pulses are emissive. In light pulses can be a high intensity (Field strength) reach, which can lead to plasma breakthrough. Furthermore, can be Light pulses with respect to Control their pulse shaping so that the plasma breakthrough in a Distance to the laser device takes place.

Especially are light pulses in the subpicosecond range by the at least one laser device emissable and especially in the femtosecond range. With such short light pulses self-focusing occurs in air due to induced Kerr effect and it can be one high field strength reach, which can lead to plasma breakthrough. It is not Telescope necessary for focusing at the place of plasma breakthrough.

Especially a self-focusing of the laser emission takes place in air. by virtue of the non-linear propagation of ultrashort light pulses during passage through the atmosphere it comes to the induced Kerr effect. This in turn happens a self-focusing of the laser emission without a telescope is necessary for focusing. In a zone of self-focus it can, if the light pulses have a correspondingly high intensity, come to the plasma breakthrough. The plasma in turn leads to a Defocusing of the laser beam. The light can spread further and then again a self-focusing may occur. Thereby a series of plasma clouds (plasma spheres) can be formed until the energy of the propagating light is no longer sufficient, to generate a plasma breakthrough. At least the place of the first Plasma breakthrough is approximately adjustable. It can also happen that Filaments (which have a diameter of the order of 100 μm) form. These form in particular along the laser beam between plasma clouds.

Cheap is it when the laser device according to the method of Chirped Pulse Amplification (CPA) is operated. In this process (see for example D. Meschede, Optics, light and laser, B.G. Teubner Stuttgart, Leipzig, 1999, pages 291, 292 and another quote there) a short pulse is stretched, to lower the peak power. The stretched pulse is amplified and the stretch is reversed by a compressor. The stretching and compression can be done, for example, via optical gratings. It is possible, the Place of self-focusing at a distance from the laser device adjust. This can be done by phasing especially on the Compressor done.

For example is the wavelength range of electromagnetic radiation emitted by the laser device different (he is for example at higher wavelengths) too the wavelength range the electromagnetic radiation to which the target acquisition responds. The destination illusion over the radiation as accompanying process of the plasma formation. Especially by a laser device can be set plasma clouds targeted, which accompanies the emission of electromagnetic radiation are. On the radiated electromagnetic waves, in particular in the infrared range, the target acquisition of a missile can react. (Due to the plasma also UV-light is radiated, so that a "deception" of UV-sensors is possible in principle.)

It is basically possible, that the Laser device for generating light pulses in a single-mode mode works or in a repetition mode in which a pulse train with a plurality of pulses (two pulses, three pulses or more) with short distance, which are for example in the order of 100 microseconds can, is formed. By operating in the repetition mode can be in the atmosphere in certain circumstances facilitate the plasma breakthrough.

All it is particularly advantageous if the location of the plasma generation at least approximately is adjustable. For example, the distance is the location of the plasma generation adjustable by a laser device. By adjusting the orientation the laser device in the room can be then the place of plasma generation in space at least approximately and thereby in turn can be a certain area of space protect.

It can be provided that the Defense device stationary is positioned. For example, it is arranged on the ground. she can serve to protect an airport.

It is also a mobile positioning possible. Through the mobile positioning For example, a mobile object (on which the positioning is provided) as a flying object to be protected. It is also one mobile positioning possible on the ground, for example, around a room area, in which plasma clouds are generated to vary.

For example, the defense device is on a flying object such as an aircraft arranged (outside or inside of the flying object) in order to protect this against attacking missiles can.

The The invention further relates to a method of defense against missiles, which one on electromagnetic radiation, in particular infrared radiation, have responsive target acquisition, which in a simple way feasible is.

These Task is inventively characterized solved, that one or multiple plasma clouds are generated in air.

The inventive method has the already in connection with the defense device according to the invention explained Advantages.

Further advantageous embodiments were also already related with the defense device according to the invention explained.

Especially the plasma clouds or plasma clouds are spaced apart to a plasma generating device generated. This can be done an effective protection against missiles to reach.

Especially plasma generation will be at a distance of at least 50 m the plasma generating device performed. This can be done a corresponding area and also the plasma generating device protect yourself effectively.

conveniently, the plasma cloud or plasma clouds are removed from one to be protected Area generated. Due to the plasma generation is usually an approaching missile not directly turned off, but only diverted (since he is over Goal fooled becomes). The deflection can be done so that he does not have to be protected Area passes or to be protected Crosses area without danger of collision.

Especially the plasma cloud or plasma clouds are formed in a region in which a self-focusing of the light pulses takes place. Such Self-focus can be for subpicosecond light pulses due to their non-linear propagation in the atmosphere. Due to the self-focusing is no telescope or the like needed at a distance to the plasma generating device a plasma breakthrough in the atmosphere to reach.

Especially become subpicosecond light pulses through the plasma generator emitted, which lead to plasma formation in air. About subpicosecond light pulses can field strengths reach the plasma breakthrough in air.

Especially The subpicosecond light pulses are transmitted through a laser device generated. By appropriate adjustment or control of the laser device can generate light pulses with such a high intensity, that it comes to plasma breakthrough in the atmosphere. Furthermore, can be Set the location of the plasma breakthrough at least approximately.

Especially is carried out such a phase adjustment in the laser device that in a predetermined distance to the laser device, a plasma breakthrough done in the air. By phasing in the laser device (For example, on a compressor of a pulse shaping device) different durations of light can be different wavelength to use that one Self-focusing at a certain distance from the laser device he follows.

Especially the laser device according to the method operated the chirped pulse amplification.

It can be provided that multiple light pulses be emitted, that is, that a laser device is operated in a repetition mode. This can be done to a relatively limited location in the atmosphere with a plurality of light pulses (For example, double pulses, triple pulses, etc.) act to to cause the plasma breakthrough. Pulse in a multi-pulse group For example, have a distance in the order of 100 microseconds.

According to the invention is a Laser device with a subpicosecond laser for plasma generation in air for Defense against missiles with targeting responsive to electromagnetic radiation used.

The corresponding advantages and other embodiments of this use have already been in connection with the device according to the invention and the method according to the invention explained.

The The following description of preferred embodiments is used in conjunction with the drawing of the closer explanation the invention.

It demonstrate:

1 a schematic representation of a first embodiment of a defense device according to the invention with stationing on the ground;

2 A second embodiment of a defense device according to the invention with an arrangement on an aircraft; and

3 a schematic representation of the method of Chirped Pulse Amplification (CPA).

A first embodiment of a defense device according to the invention is in 1 shown and there with 10 designated. It serves to defend against missiles 12 such as rockets (with warhead) or smart ammunition, the target detection device 14 which responds to electromagnetic radiation. Such a target detection device 14 For example, it includes one or more opto-electronic sensors that detect electromagnetic radiation, such as infrared radiation. The trajectory of the missile 12 is during the flight via the target detection device 14 controlled so that it follows the source of electromagnetic radiation. For example, a source of infrared radiation is an aircraft engine.

The defense device 10 comprises a plasma generating device 16 with a laser device 18 , The laser device 18 is an ultrashort pulse laser device; They emit light pulses in the subpicosecond range and in particular in the femtosecond range.

For example, the laser device includes 18 an oscillator 20 and a pulse shaping device 22 ,

In the embodiment shown, the laser device 18 stationary on the ground 24 arranged. It can also be provided that they are mobile on the ground 24 is positionable (this is indicated by the arrow with the reference numeral 26 indicated).

The laser device 18 emits subpicosecond pulses, spaced at one or more locations from the plasma generator 16 light pulses 28 ( 3 ) can be achieved with such high intensity that it comes to the plasma breakthrough in the air and one or more plasma clouds 30 ( 1 ) form. In particular, the place where the plasma cloud or plasma clouds 30 form, adjustable. This adjustment can be achieved by means of a phase adjustment taking into account the non-linear propagation of the light pulses of the laser device 18 done in air.

It has been shown, for example, that light pulses are produced by a subpicosecond laser 28 with an intensity that leads to the plasma breakthrough in air, at a distance of about 10 km from the laser device 18 let generate.

Of the Plasma breakthrough can be for example, at a distance of about 10 m to a distance range of several kilometers. This area is adjustable.

Due to the non-linear propagation of the generated ultrashort light pulses, self-focusing of the laser emission due to the induced Kerr effect occurs when passing through the atmosphere. By the self-focusing can in a range (with a preferably adjustable distance to the laser device 18 ) the plasma breakthrough threshold in the atmosphere is exceeded. Due to this (self-) focusing no special imaging optics such as a telescope is necessary.

At the place of the plasma breakthrough forms a plasma cloud (plasma ball). The plasma has a defocusing effect on the light. In the further Lichtpropagation can the self-focusing effect again become effective and at a distance to the first formed plasma cloud it can form another plasma cloud, etc. It can form a series of plasma clouds, until the intensity of the propagating Light pulse is no longer sufficient, the plasma breakthrough threshold in To cross the air.

It is possible, too, that one Filamentation aufgritt. Especially between adjacent plasma clouds can along the light path plasma filaments with a diameter form of about 100 microns.

It is possible that the laser device 18 is operated in a single-pulse mode or in a repetition mode. In the repetition mode, a pulse group with, for example, two, three or more pulses is sent, wherein the distance of the pulses in a pulse group is smaller than the distance of pulses of different pulse groups, which are transmitted one after the other. For example, the distance of pulses within a pulse group is approximately 100 μs. This may facilitate the plasma breakthrough under certain circumstances.

The generated plasma leads for the emission of electromagnetic waves, in particular due to of recombination processes of the plasma. Among other things, a Radiation in the infrared range.

On these electromagnetic radiation, the target detection device 14 of the missile 12 react; the radiation emission of the plasma cloud 30 (especially the collapsing plasma) deceives the target detection device 14 of the missile 12 the presence of a radiating object in front of and the missile 12 becomes through the target detection device 14 to the plasma cloud 30 directed. It thus takes place via the plasma generating device 16 generated plasma cloud 30 a target deception for the missile 12 ,

The wavelength range of the light pulses generated by the laser device 18 can be emitted outside the wavelength range to which the target detection device 14 of the missile 12 responds, lie. For example, laser pulses are emitted in a wavelength range around 800 nm, that is to say in the short-wave infrared range.

In a second embodiment, which is in 2 shown is a defense device 32 on a flying object such as an airplane 34 with engines 35 assembled. The defense device 32 has a plasma generating device 36 which is basically constructed as described with reference to the first embodiment. By the plasma generating device 36 grasp themselves at a distance to the flying object 34 generate one or more plasma clouds, using a missile 40 (such as a rocket or smart ammunition) with target detection on the electromagnetic radiation emitted by the plasma cloud 38 emanating, can react and thereby from the flying object 34 can be distracted.

For the production of light pulses 28 of such high intensity that it comes to plasma breakthrough in air and thus a plasma cloud 30 respectively. 38 is formable, this plasma cloud 28 respectively. 30 at a distance (and in particular large distance) to the defense device 10 respectively. 32 For example, the method of Chirped Pulse Amplification (CPA) may be used. This method is described for example in D. Meschede, optics, light and laser, BG Teubner Stuttgart, Leipzig, 1999 in chapter 8.5.5 with citation.

An oscillator 42 gives a short pulse 44 from. By a straightener 45 the pulse shaping device 22 This short pulse is stretched in time to lower the peak power (pulse 46 ). Through an amplifier 48 becomes the stretched pulse 46 strengthened. The resulting pulse 50 is compared to the pulse 44 long.

The stretching is then done by a compressor 52 reversed, in such a way that the resulting light pulse 28 with high intensity (which may be on the order of 10 ¹³ W / cm ² ) outside the plasma generator 16 provided. Through the compressor 52 becomes the original form of the short pulse 44 restored.

In cooperation with the non-linear propagation in air can be achieved by a phase balance in the laser device 18 in an at least approximately set distance from the laser device 18 cause a self-focus.

The Strecker 45 can be realized for example via an optical grating. Also, the compressor can be 52 realize via an optical grating. Through an optical grid, red and blue parts of an incoming pulse can be resolved 44 respectively. 50 bend in different directions.

For example, the compressor 52 designed such that via the optical grating, such a phase adjustment takes place, that the self-focusing, which leads to the plasma breakthrough in air, at a defined location spaced from the laser device 18 arises.

According to the invention, a laser device 18 with a subpicosecond laser used to missiles 12 respectively. 40 to deceive with opto-electronic target acquisition by generating a plasma in air, which is accompanied by the emission of electromagnetic radiation, in particular recombination radiation.

The Inventive defense device can be stationary or mobile use. about she lets herself go generate plasma in a defined area of space. This can be done also protect a defined space area. In particular, the Space in which the plasma is generated, in a sufficiently large distance from one to be protected Area selected.

By the defense device 10 For example, you can protect an area around an airport.

Claims (24)

Defense device against missiles ( 12 ; 40 ) with targeting to electromagnetic radiation, in particular infrared radiation, ( 14 ) comprising a plasma generating device ( 16 ), in which in air at a distance to the plasma generating device ( 16 ) A plasma can be generated. Defense device according to claim 1, characterized in that by the plasma generating device ( 16 ) one or more plasma clouds ( 30 ) are produced in air. Defense device according to one of the preceding dependent claims, characterized in that the plasma generating device ( 16 ) at least one laser device ( 18 ), are emitted by the light pulses. Defensive device according to claim 3, characterized in that by the at least one laser device ( 18 ) Light pulses in the subpicosecond range are emitted. Defensive device according to claim 3 or 4, characterized in that the laser device ( 18 ) is operated according to the method of chirped pulse amplification. Defense device according to one of claims 3 to 5, characterized in that the wavelength range of the laser device ( 18 ) emitted electromagnetic radiation is different from the wavelength range of the electromagnetic radiation to which the target detection ( 14 ). Defensive device according to claim 6, characterized in that the wavelength range of the laser device ( 18 ) emitted electromagnetic radiation at longer wavelengths than the wavelength range to which the target detection ( 14 ). Defense device according to one of claims 3 to 7, characterized in that light pulses are emissive in a repetition mode. Defense device according to one of the preceding claims, characterized characterized in that Place of plasma generation is at least approximately adjustable. Defense device according to one of the preceding claims through a stationary Positioning. Defense device according to one of claims 1 to 10, characterized by a mobile positioning. Defense device according to one of the preceding claims by positioning it on the ground. Defense device according to one of claims 1 to 10, characterized by a positioning on a flying object ( 34 ). A method of defense against missiles, which one on electromagnetic Radiation, in particular infrared radiation, reactive target detection in which one or more plasma clouds are generated in air become. Method according to claim 14, characterized in that that the Plasma cloud or plasma clouds spaced to a plasma generator be generated. Method according to claim 14 or 15, characterized that the Plasma generation at a distance of at least 50 m to the plasma generating device he follows. Method according to one of claims 14 to 16, characterized that the Plasma cloud or plasma clouds away from a protected area Area are generated. Method according to one of claims 14 to 17, characterized that by a plasma generating device emits subpicosecond light pulses become. Method according to claim 18, characterized that the Plasma cloud or plasma clouds are formed in a field in which a self-focusing of the light pulses takes place. Method according to claim 18 or 19, characterized that the Subpicosecond light pulses are emitted by a laser device. Method according to claim 20, characterized in that the existence such phase alignment is performed on the laser device, that in a plasma breakthrough at a given distance to the laser device takes place in air. Method according to claim 20 or 21, characterized that the Laser device according to the method the chirped pulse amplification is operated. Method according to one of claims 18 to 22, characterized that multiple light pulses be emitted. Use of a laser device with a subpicosecond pulse laser for plasma generation in air for defense against missiles with targeting responsive to electromagnetic radiation.