DE1949342B2 - DEVICE FOR PERIODIC DEFLECTION OF A BEAM OF LIGHT - Google Patents

Description

use is made of a fixed surface in the area of a desired position of the rotary prism, öx

directly influenced. In other words, it comes from the rotary prism and thus from the prism arrangement

Anyone who insists that the optical holder consists of such a fixed prism is the reason

sctael opens the resonator as possible and after the surface of the rotating prism a regular triangle and J

e locks for a long time. 5 also the base of the fixed prism em

The invention is based on the object for triangle. _de i: _e _

a device of the type described in the introduction, How extensive, the invention is based on Mie_

Especially with regard to their application in low studies, it is special

mesSpulslasera, another solution to raise, which is advantageous, the base of the rotary pram

to the ETS simple means for xo as a regular square in vern Jhlässigbaren, d also <J ^ie Jmndflache

With a given rotation of the fixed Pnsmas or the fixed

ospeed of the rotating prism to form the deflecting prisms as a square.

^hie Ceh "nd rule of a device for perio _dl, 5 emergent light beam are special by t _he ^ Ablenkune a light beam preferably a configuration of the Drehpnsmas and de .hm trains in 'r pofarisierten coherent light beam predetermined child stationary ^ Pnsmc, ^. Wmi turn of the beam path regardless of the ruled P ^ J ^ J. Drehpnsmas, about an axis given to your rotary direction of the em- und_aust »s ^. ^ is driven BEU une, this object is desired according ™ beam so can ^oies , ^Π '? £ £. · Invention! solved in that the rotating prism is partially assigned a fixed prism, at least one more, a change ⁱⁿ the ^f " ^tstehend "J ^ to cSrdnet, and that the design of the prisms Strahlein- and / or output beam as well as the arrangement of the prisms, both counter 25 assembly is provided of the. _{h DJE}

sei.io as well as to the incoming light beam so To the beam losses when passing through am , na

is selected. that in at least a certain prism arrangement in vernachtes.gbar KLE> Nengren ^ rotational position de, the rotating prism of the hold zen through the prism, m is further dr tsrnna arrangement passing light beam in a prism assembly so * ^Mes * £, j ^ S Zvklus successively the rotating prism, the fixed- 30 the angle at which the. lmearly transposed UcM standing prism and again the rotating prism or beam in a certain rotational position, the rotation passes through the reverse, namely one or more times. pri.au »the g ^ g ^ SS breaking it,

In the invention, by the realization off arrangement through which, for sarntUctte ^D ™ * ne ceaaneen that in alternate reflection of an area equal to the Brewsterwmke is 11Λ other ScnSls to a rotated and fixed at a 35 part, the beam deflection within the e.nes Pns

ÄSls ^ Us t ffSffÄÄ J ^

£ Wmkelischwindigke. the rotated ^ surface ^ alsG.es ^^^^^^

^e D ° a high demands on the accuracy of a- ₄ o special one ^ impulslase.s according to

on the one hand the dimensions of the prisms and on the other hand, hanging next to an elevation

Are mutual arrangements are made, it is shortening of ^Üba ^ ^s P ^ha 7 ^ ^S "

expediently, the prisms of the prism arrangement as from the open to the

Polygon priLen with oolised flat side surfaces ^^^^

BLNS favorable conditions are then also the second Resonate can here j _e gel dormant

when the rotating prism, which can be attached with respect to the axis of rotation. This makes him m toua

Ξ "high s / mmetrie, regular and ^ cht met limited .md can ^ ach ^ need with

equilateral with the rotation axis parallel polished "only arbitrarily J ™™ ^ _{no direction nac} h of the flat side surfaces is designed in this training 50 ^se ^ ^{s are} _{nd, wa} rt her from the Brewster angle

Formation of the rotary prism can for one in the invention, namely ¹ V " ¹ ^," _{of the light} _

S Dhh flashed light beam ^ - ^^ ft

formation of the rotating prism can ü ^, _{which the light} _

Plane of light beam deflected to the axis of rotation ^ - ^^ ft Polygonpri ™, all side surfaces both refractive and totally reflecting. ^^ _Λ ^ £ ηί interfeXmSrischen. τικΗρπιπο of the deflecting corisms to each other and

If a high multiplication factor is desired 55 ^J ™ _d | _r ^^ Sffii ^ cil the Fresnel losses then this can be achieved in a simple way by ^l ^ ^h ^ ⁵⁰ ^ "^^" ^ 8 um " _B around the fact that two or more fixed prisms at Versummeη aes w ₁ _ _cos2 M _{B an-}

at a given distance from the rotational principle value Aa ₁ , just see Mang «n b _q ^ _

are arranged, which are set up here around the rotating prism ^^ - ^ "^ 'StaWenkeinrichtung is in hemm so that I dei _p beam circulation. 60 ^s * ^al g; j ⁿ ^ J ^ _r ^e _hteI1 significantly shortened

"A special embodiment after the _{laser arrangement} indicates with a first

Invention in which a multiple, alternating ¹ J ™? ™ _{άη & a} f _{s optical} switch

Selective reflection on a rotated and an Ausunrungsoeispie. iur cmc _v

used light deflection device according to the invention and then finally occurs as a light beam 9 '

from the prism array on the top right

F i g. 2 shows a first extension of a light deflecting side surface, again at the Brewster angle.

device according to Fig. 1, the passage of the stimulated radiation through the

F i g. 3 a second extension of a light deflection 5 rotating prism 1, the fixed prism 2 and again-

Device according to FIG. 1, in order to pass through the rotary prism between the entry

F i g. 4 shows a variant of the device for deflecting the light into the prism arrangement and its

according to Fig. 3, causes exit towards the multiple etalon 8

F i g. 5 a the increased light deflection speed compared to the angular speed ω around the

the light deflection device according to FIG. 1 explanation factor four increased deflection speed of the

terning diagram, radiation between entry and exit. Regarding

F i g. 6 a laser arrangement with a second of the aperture 7 ″ of the laser arrangement 7 is this er- Embodiment for an optical switch increase the deflection speed even by the

used light deflection device according to the invention factor eight higher than the angular velocity ω

manure. 15 de «Rotary prism 1, because the one on the multiple etalon 8 '

In Fig. 1, the laser arrangement 7 consists of a reflected portion between the exit from the laser-pumped active, rod-shaped medium 7 ', the arrangement 7 and the re-entry .n the laser arrangement is arranged within an optical resonator. tion passes through the light deflector twice. The optical resonator in turn consists of a deflection speed of the radiation 9, the first fully reflecting mirror 8, which here ao according to FIG. is upset. This can be increased to six times the value of the second partially transparent mirror is a multiple increase that, as shown in FIG. 2 indicated etalon 8 ', which here is outside the actual, a second fixed prism 3 provided laser arrangement 7 is provided. A diaphragm 7 ″ a *, which is limited on the circumference of the rotating prism 1 opposite, is offset by 90 ° from the mirror-free end of the fixed prism 2. The incoming radiation 9 emerging from the stimulable medium T now passes through, like radiation 9, 1, first the rotating prism 1, light deflecting device according to the invention between then the fixed prism 2 and then returning to the mirror 8 and the multiple etalon 8 'and 3' from there again into the rotating prism 1 This is reflected back with a simultaneous passage cycle is then repeated over the fixed part of this radiation through the multiple prism 3 before the radiation finally etalon 8 'into the outer space, which emerges again in the beam path from the prism arrangement, the stimulated radiation 9 arranged light A corresponding arrangement for a deflecting device opposite consists of a with the angle 35 of the angular velocity ω of the rotating prism 1 by speed ω in the direction of the arrow around the axis a factor of eight increased deflection speed of the rotating prism 1 rotating perpendicular to the plane of the drawing, radiation is shown in FIG. 3. Here use is made of three fixed with a square base and parallel to the standing prisms 2, 3 and 4, the axis of rotation running flat, rumbled side surfaces on the circumference of the rotating prism 1 at equal intervals. The rotating prism 1 is a fixed 40 prism 2 with a rectangular base area and offset in a trapezoidal manner in each case by 90 ° in the circumferential direction.

assigned shaped cross-section. The arrangement As FIGS. 1 to 3 make clear, that of the fixed prism 2 to the rotary prism 1 as the angle between the impinging in the prism arrangement, the relative position of its refracting surfaces and the radiation 9 emerging from it to the rotary prism are chosen so that in the 45 radiation 9 'on the configuration of the ^L: ht-F i g. 1 specified rotary position of the rotating prism 1 deflecting device representing prism arrangement and determined in each by 90 ° or whole multiples thereof. If, regardless of the angle of rotation deviating from the prism, the illustrated flong fee is given an angle change between the exit beam path, the radiation 9 fed into the prism side and the exit side arrangement from the rotating prism 1 and the fixed 50 emitted radiation ψ is desired or should the standing prism 2 incoming radiation 9 hits the angle between the input and output radiation 180 ° at the Brewster angle <% _B on the upper left, so this can occur for an arrangement on the side face of the rotating prism and occurs, linear Fig. 3 as well as for the arrangements according to Fig 1 polarization of the stimulated radiation 9 in the and 2 are brought about by the fact that on the plane of the drawing, assuming that further fixed prism prisms are completely inserted into the rotary catch of the rotary prism 1, on the right upper side surface, the desired rectilinear with carrion use of total reflection to the right course between egg Deflected on the input side and the output side lower side surface, more radiation occurs there. In Fig. 4, the arrangement of which at the Brewster angle% _B ans and under voltage essentially corresponds to the arrangement according to the same angle in the fixed prism 2 60 Fig. 3, there are two further fixed ones. As the weathered beam path shows, beam prisms S and 6 are provided, of which the fixed deflection on the base of the fixed standing prism 6 with trapezoidal grand surface prism 2 by total reflection and exit aas the entrance and the fixed prism 5 with flat left side surface in turn below the Brewsterfall trapezoidal base the angle. The radiation then enters the rotating prism 1 at the same angle as it emits a light deflection device. 1 side surface is shown using total reflection up to 4, regular poly-

(ο

gonprismcn with a larger number of corners uses the duration of the light pulse with simultaneous will. Depending on the number of corners, the rising and falling flanks can also be steepened even more fixed prisms in the sense of a considerably shortened. When using an arrangement The increase in the multiplication factor by the amount shown in FIGS. 2 or 3 is the duration of the angular velocity of light of the rotating prism increased 5 impulses with simultaneous further steepening of the Deflection speed can be provided. How flanks get shorter and shorter.

shows, however, result in polygonal prisms with the laser arrangement according to FIG. 6 with a higher number of corners, taking into account the light deflecting device according to the invention, the worst conditions, in particular those relating to the visible laser arrangement and the optical transition of the radiation from one medium into the resonator using the same elements other than the Brewster angle, are relative made as in the arrangement according to FIG. 1. The same large dimensions for such rotary prisms. Parts are provided with the same reference numerals, so that the fourth power of the radius is taken into account that, as far as there is agreement, a growing unbalance forces are reduced, the full discussion is superfluous. The speed allowed as an optical switch is quite considerable. In addition, the light deflection device used consists in turn increase with increasing glass volume of the prism from a rotating prism 1 ', which in the present case arrangement does not reduce the absorption losses in the glass but the base area of a simultaneous triangle increases proportionally. However, lead also has rotational features. The fixed prism also has a prism with a minimum number of corners η = 3 in a triangle as a base area, but has a large number of applications that cause difficulties. For ao measurements. Here, too, the light deflection device is a regular polygon prism with three corners for a rotary position of the glass volume can be kept relatively small with the angle, speed ω around an axis perpendicular to the drawing, but here there is the requirement to display types of glass with a flat rotating prism 1 'shown in to use a relatively high refractive index if the light deflecting device has the desired properties of the full prism arrangement, described with reference to the reflecting mirror 8 and the multiple etalon 8 'vcii Fig. 1, existing optical resonator in the sense of the requirement. Are high requirements with respect to the excitation of a pulse-shaped, stimulated optical light and the chemical resistance of such a beam activated periodically. The arrangement is again made of glasses, then it is very difficult to find a suitably dimensioned so that for all the radiation-burned glass with the required high refractive surfaces of both the rotating prism Y and the index. Thus, rotating prisms with quad stationary prism 2 'represent the angular condition of the dratic base area a certain optimum for, according to Brewster, to be fulfilled. The radiation 9 emanating from the laser arrangement represents such a light deflection device - Guided and from there after passing through the th light deflection speed are guided in Fig. 5 via rotating prism to the fixed prism 2 'back time / the light amplitude A of a light beam. After a second cycle, the constant intensity for a certain target direction radiation then emerges from the fixed prism 2 '. In the area of the point of impact deflected by the light deflection device, a further prism 2 'light beam is provided for a rotating prism with a square shape, which turns the exiting radiation 9' into a base area at an angular velocity ω in a direction parallel to the entering radiation 9 (curve a) without a fixed prism and to steer. Corresponding to a double reflection the other time (curve b) with a fixed radiation applied to a rotating and to a fixed prism in the arrangement according to FIG. 1. 45 the area is the light deflection speed dei. As the comparison of the curve α with the curve b, the output radiation 9 'is increased by a factor of six, the rotation speed ω of the rotating prism 1' is increased at the angle speed ω according to the invention

1 sheet of drawings

Claims (9)

refractive surfaces equal to the Brewster angle claims: («ß) and on the other hand the beam deflection within one of the prisms by total reflection 1. Establishment for periodic diversion takes place. a light beam, preferably a linear pola- 5 9. Use of a device according to a ized coherent light beam, using the preceding claims as an optical one tion of a rotary Q-switch arranged in the beam path within the optical resonator prism, which around an axis to a rotary movement (8, S ") of a working according to the laser principle is driven by the optical transmitter or amplifier, draws that the rotating prism (1, Y) little io
at least one fixed prism (2, T) assigned is that at a predetermined distance to the Rotary prism is arranged, and that the design of the prisms as well as the arrangement of the Prisms both to each other and to the incoming light beam is chosen so that in little to the periodic deflection of a light beam, primarily a certain rotational position of the rotary, preferably a linearly polarized coherent light prism through the prism arrangement towards the beam, using a light beam passing through in the beam path in a cycle arranged downstream of the rotating prism, the rotating prism, the stationary 20, is driven in a rotating movement about an axis relative to one another.
The prism and, in turn, the rotating prism or devices of this type can, for example, run through in the opposite direction, namely one or more times. for writing in or querying a reading 2. Device according to claim 1, characterized by ge information from an electro-optical or holo, that the prisms (1, 1 ', 2, 2', 3, 4) graphic memory by means of a light beam in front Prism arrangement polygon prisms with 25 can be seen. Also for the holographic refurbished are flat side surfaces. would take moving objects according to the grid principle 3. Device according to claim 1 or 2, that such light deflection devices can be used marked, d.nß the rotating prism (1,1 '), reach dung. which has a high degree of symmetry with regard to the axis of rotation. Periodic dimensions are particularly important has, regularly and equilaterally with 30 steering a light beam with the help of a to one Polished, flat lateral symmetry axis driven rotating prism for flattening parallel to the axis of rotation is designed. realization of an optical switch for giant 4. Obtained facility according to one of the preceding pulsed lasers. Just be an example in this one Claims in which two or more established connections to the book by Dr. Röß, »Laser, Prisms at a given distance from the light amplifier and oscillators «, Academic Ver-Drehprisma are arranged, thereby marked society, Frankfurt / Main, 1966, Chapter 13, draws that the fixed prisms (2, 3, 4) in particular p. 367 and 368, pointed out. The twist the rotating prism (1) are set up around, prism represents one of the two, the that the beam circulation cycle rotating prism - fixed - resonator forming mirror, namely the complete prism - rotating prism between a reflecting mirror, represents. Such a resonator passage of the light beam into and exit of the light points only at a given rotational position of the Beam from the prism array successively rotating prism a useful quality, because only for the individual fixed prisms. in this particular position one in the optical 5. Device according to one of claims 1 axis of the resonator incoming light beam from to 3 with a fixed prism, thus 45 rotating prism to the other mirror again in the characterized in that the base of the rotary optical axis is reflected. The rotating prism prismas (1 ') a regular triangle and also switches, in other words, the quality of the optical the base of the fixed prism (2 ') resonator between a negligibly small is a triangle. and a very great value in the rhythm of one 6. Device according to one of claims 1 to 50 revolutions, whereby in the period of a low to 4, characterized in that the basic quality is that arranged in the optical resonator surface of the rotating prism (1) a regular four-stimulated medium to very high inversion values corner and also the base of the stationary can be pumped and against this time prism (2) or the fixed prisms (2, space a very short period of high quality of the 3, 4) is a square. 55 optical resonator the stored energy in 7. Device according to one of the preceding form of a light pulse of very short duration in the Claims, characterized in that it emits little order of magnitude of nanoseconds. At least one more, a change in direction The speed of rotation of the rotating prism and The fixed prism serving the light beam thus the deflection speed of the light beam (5, 6, 2 ") can be used as the jet inlet and / or jet outlet 60 with regard to the drive unit the prism assembly is provided. on the one hand and the resilience of the rotating prism 8. Device according to one of the preceding can not be increased arbitrarily by the centrifugal forces. Claims, characterized by such a straight line for the application of such devices Dimensioning of the prism arrangement that on the one hand comes as an optical switch in giant pulse lasers the angle at which the linearly polarized 6s cause a high speed of deflection of the light-light beam in a certain rotational position of the beam to a large extent, as the size Rotary prism, the surfaces refracting it, the deflection speed of the light beam Immediate structure, for all edge steepness of the developing light pulse