JPH0342420Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" This invention relates to a light beam deflection device capable of electrically deflecting a light beam or electrically deflecting a light receiving axis.

"Prior Art" As a conventional deflection device for deflecting and transmitting/receiving a light beam, mechanical light beam deflection means have been mainly used. For example, a voice coil was used to control a mirror to change the direction of the mirror, thereby changing the direction in which a beam of light incident on the mirror was reflected.

Alternatively, the mirror was rotated by a motor or the like to form a rotating mirror, and the light beam was deflected in synchronization with the rotation.

``Problems to be Solved by the Invention'' With such mechanical light beam deflection control means, high-speed deflection control is difficult because the direction in which the light beam is reflected is controlled by moving a reflecting mirror.

Since the deflection means has mechanically moving parts, there is also mechanical vibration, which often causes failures and is poor in reliability.

In addition, mechanically movable parts inevitably suffer from wear and deformation, and these also cause large changes over time, which poses a number of problems.

``Means for solving the problem'' In this invention, the optical beam transducer that emits a light beam has a plurality of optical transceiver ends arranged at a predetermined interval, and their respective emission axes are parallel to each other. The configuration is such that coherent light is emitted from each of the plurality of optical transmitting/receiving ends in the direction of the radiation axis, and one end of each separate optical transmission line is connected to each of the plurality of optical transmitting/receiving ends. An optical delay control element is inserted into each of the plurality of optical transmission lines, and the delay of light propagating through each optical delay control element is controlled by an electrical signal.

On the other hand, each other end of the optical transmission line including these optical delay control elements is coupled to an optical coupler, the plurality of optical transmission lines are connected to one, and the single transmission line is used to generate coherent light. or a light-receiving element.

Furthermore, in this invention, a controller for the optical delay controller is provided, and this controller controls the amount of delay of the optical delay control elements in the plurality of optical transmission lines, and controls the direction of the optical beam emitted from the optical beam transducer. The device is configured to control the direction of deflection.

Embodiment FIG. 1 is a diagram showing an embodiment of a light beam deflection device according to this invention. This example has a coherent light source 11, and emits light emitted from the coherent light source from radiation ends 14A to 14N,
A case will be described in which the radiation beam is electrically deflected.

The light beam whose deflection is controlled is phase-aligned coherent light from a laser or the like, and is emitted by the coherent light generator 11 . The coherent light whose emission has been controlled is guided to the optical waveguide 12 and sent to the optical beam transducer 13.
It is radiated from 3.

In this invention, the optical beam transducer 13 has a plurality of optical transceiver ends 14A, 14B, 14C,...14N.
will be established. Coherent light is emitted from each of the optical transmitting/receiving ends 14A to 14N in the direction of each radiation axis M. In this example, optical transmitting/receiving ends 14A to 14
A case is shown in which N are arranged in a line at approximately equal intervals d. Further, the optical transmitting/receiving ends 14A to 14N are arranged so that the emission axes M of the respective coherent lights of these optical transmitting/receiving ends 14A to 14N are parallel to each other.

One end of each optical transmission line 15A-15N is connected to each optical transmitting/receiving end 14A-14N, respectively.
In this invention, optical delay control elements 16A to 16N are provided in these optical transmission lines 15A to 15N, respectively. That is, these optical delay control elements 16A to 16
When coherent light propagates within N, the light undergoes a phase delay due to the optical delay characteristics of each of the optical delay control elements 16A to 16N.

For each of these optical delay control elements 16A to 16N, an acousto-optic element or the like can be used so that the optical delay amount φi for causing a phase delay in the propagating light can be electrically changed. Each optical delay amount φi is determined by the controller 17
Controlled by

The other end of each of the optical transmission lines 15A to 15N is connected to the optical distribution ends 18A to 18N of the optical coupler 18, respectively. The optical coupler 18 receives the coherent light from the coherent light generator 11 through the optical waveguide 12 from its light input end, and sends the input light from each of the optical distribution ends 18A to 18N to the optical transmission path. The structure is such that it is distributed and supplied to 15A to 15N with approximately equal strength.

"Operation" In the above configuration, the light from the coherent light generator 11 is input to the light input end of the optical coupler 18 via the optical waveguide 12. Optical coupler 18
divides the incident light into approximately equal light intensities, and connects each optical transmission line 15A to 15N from the light distribution ends 18A to 18N.
Distribute into 15N. The coherent light distributed to each optical transmission line 15A to 15N is
The optical delay control elements 16A to 16N inserted in the middle of the optical transmission lines 15A to 15N each receive a phase delay φi, and the emitted optical axis is emitted from the optical transmitting/receiving ends 14A to 14N connected to each optical transmission line 15A to 15N. M
are radiated in the respective directions.

The coherent light emitted from the optical transmitting/receiving ends 14A to 14N is transmitted to each emitted optical transmitting/receiving end 14A.
It propagates by forming a semicircular wavefront centered at ~14N. As the light travels from the optical transmitting/receiving ends 14A to 14N, the traveling wavefronts of the respective lights expand and overlap each other, and the overlapping wavefronts interfere with each other. Due to this wavefront interference, wavefronts that are in the same phase strengthen each other, and wavefronts that are in opposite phases weaken each other.

In this invention, each coherent light is subjected to a predetermined phase delay φi by the optical delay control elements 16A to 16N before being emitted from the optical transmitting and receiving ends 14A to 14N.
The synchrotron radiation emitted from the optical transmitter/receiver ends 14A to 1
For example, 14A, 14B, 1 according to the arrangement order of 4N.
When the phase delay amount is set to decrease by φ in the order of 4C, ...14N, each coherent beam radiated from each optical transmitting/receiving end 14A to 14N in the direction of the radiation axis M as shown in FIG. are A ₁ , A ₂ ,
One composite wavefront P connecting A ₃ ,...A _N is formed, and the main component of the coherent light is directed in a direction perpendicular to this composite wavefront P, and is deflected in a direction deviated by an angle θ from the radiation axis M. . This deflection angle θ is θ
It can be expressed as = sin ^-1 [(λ/d)・(φ/2π)].

Here, d is the spacing between the optical transmitting/receiving ends 14A to 14N, and φ is the adjacent optical delay control element 16A to 1
6N represents the difference in phase delay amount φi of light.

That is, by changing the amount of optical delay of the optical delay control elements 16A to 16N using the controller 17,
It becomes possible to control the deflection angle θ of the light beam. For example, mutually adjacent optical transmitting/receiving ends 14A~
By controlling the phase difference φ of the light emitted from the 14N so that it changes continuously, the deflection angle θ can be changed continuously. In other words, it becomes possible to control the deflection and scanning of the light beam.

"Modified Embodiment of the Invention" FIG. 3 is a diagram showing another example of the optical beam transducer 13.

In this example, a plurality of optical delay control elements 16A to 16N are arranged in series on the optical transmission line 15, and each optical delay control element 16A to 16N is controlled to have the same phase delay characteristic φ. This optical beam transducer 13
Then, coherent light is incident from one end 13a, a part of which is emitted from the first optical transmitting/receiving end 14A, and the other part is subjected to a phase delay of φ by the first optical delay control element 16A. A part of the coherent light that has undergone a phase delay is transferred to the second optical transmitter/receiver end 1.
4B, and the other part further passes through the next second optical delay control element 16B and undergoes a phase delay of φ.

In this way, it is configured to sequentially radiate a portion of the radiation while undergoing a phase delay of φ one after another.

Also in this case, each optical delay control element 16A to 16N
The phase delay characteristic is controlled by the controller 17 so as to change while maintaining the same characteristic over time, and the directional direction θ of the emitted light beam can be controlled in the same way as in the previous embodiment. However, in this case, since the delay relationship between each radiation time is in a fixed direction, the deflection angle θ is limited to deflection to one side with respect to the radiation axis.

In the example of FIG. 1, the optical beam transducer/receiver 13 has the optical transceiver ends 14A to 14N arranged in a row at equal intervals, but this is not a one-dimensional arrangement.
As shown in FIG. 4, optical transmitting/receiving ends 14A to 14N
may be arranged two-dimensionally on a plane at equal intervals. According to this optical beam transmitter/receiver 13, the optical beam is not only subjected to one-dimensional deflection scanning control in the X direction, but also optical delay control connected to the optical transmitter/receivers 14A to 14N arranged adjacently in the Y direction. Control element 1
If the optical delay control elements 16A to 16N are controlled so that the phase difference of the optical delay characteristics of 6A to 16N becomes φ and the phase difference φ changes, deflection scanning control in the Y direction is also possible. , two-dimensional plane deflection scanning control becomes possible.

In this case, the optical transmitting/receiving ends 14 in the X direction and the Y direction
The arrangement intervals of A to 14N do not necessarily have to be the same.

In the above description, only the light beam transducer 13 emits a light beam and performs deflection scanning, but the light beam transducer 13 can also select and receive coherent light.

In other words, consider the previous explanation in reverse.
Each optical transceiver end 14A to 1 of the optical beam transducer 13
The coherent light incident on 4N is transmitted to the optical transmission line 15A connected to the optical transmitting/receiving ends 14A to 14N.
~15N respective optical delay control elements 16A~1
6N receives a phase delay φi due to the respective phase delay characteristics, and the optical distribution ends 18A to 1 of the optical coupler 18
8N enters the optical coupler 18 and is combined into one light beam.

Although not shown in the figure, at this time, the optical coupler 18
At the optical coupling end of the light beam, each coherent beam of light interferes with each other. In other words, if the difference in the delay characteristics of the adjacent optical delay control elements 16A to 16N is φ, then the lights coming from the direction θ expressed by the above equation will have the same phase at the optical coupling end of the optical coupler 18, and will become stronger than each other. However, light incident from other directions is out of phase with each other and cannot be strengthened. Therefore,
Light coming to the optical beam transducer 13 from each direction can be selectively received.

``Effects of the invention'' Compared to conventional optical beam deflection scanning using mechanical deflection means, there are no moving parts, so there is no mechanical vibration or malfunction caused by it, and there is no change over time such as wear or deformation. Therefore, a highly reliable optical beam deflection device can be realized.

Further, by providing a laser amplifier in each optical transmission path after the optical coupler, it is possible to relatively easily realize an optical beam deflection device that enables deflection scanning of a high-output optical beam.

Furthermore, it is possible not only to control the deflection and scanning of the light beam, but also to selectively receive coherent light coming from a specific direction from among many coherent lights coming from various directions.
Moreover, it is possible to receive any light by electrically controlling the optical delay amounts φ, φ, etc., and it can also be applied as an optical multiplexer, which is highly effective.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the configuration of the optical beam deflection device according to this invention, Fig. 2 is a diagram showing how coherent light is emitted from the optical transceiver end of the optical beam transducer, and Fig. 3 is a diagram showing the configuration of the optical beam deflection device according to this invention. FIG. 4 shows an example of an optical beam transducer configured by arranging delay control elements in series.
The figure shows an example in which optical transmitting/receiving ends are arranged two-dimensionally to enable plane deflection scanning control. 11: Coherent light generator, 12: Optical waveguide, 13: Optical beam transmitter/receiver, 14: Optical transmitter/receiver end, 15: Optical transmission line, 16: Optical delay control element, 1
7: Controller, 18: Optical coupler.

Claims (1)

[Claims for Utility Model Registration] A. A plurality of optical transmitting/receiving ends arranged at predetermined intervals so that their radiation axes are parallel to each other; B. A plurality of optical transmitting/receiving ends coupled to the plurality of optical transmitting/receiving ends. an optical transmission line, and C inserted into each of the plurality of optical transmission lines,
an optical delay control element capable of delaying light propagating through each optical transmission line and controlling the amount of delay by an electrical signal; D coupling the optical transmission lines including this optical delay control element into one; an optical coupler coupled to one coherent light generator or one light receiving element; A light beam deflection device consisting of a controller that controls the direction of the beam.