JPS6347734A - Light deflecting element - Google Patents

Abstract

PURPOSE:To deflect beams in an optional direction by using a solid-state electron beam source for generating grating-like electron beams. CONSTITUTION:A face-like optical waveguide D consisting of a ferroelectric substance is formed on a substrate S and the solid-state electron beam source MEB is arranged oppositely to the optical waveguide D. The solid-state electron beam source MEB generates electron beam flux EB having a grating-like pattern on the basis of plural electron beams and minus electrostatic charge is generated from the optical waveguide D opposed to the MEB in accordance with the electron beam flux EB radiated from the MEB. A ferroelectric part irradiated by the electron beam flux EB through the optical waveguide D changes its refractive index by electrostatic charge and a grating pattern G with a high refractive index corresponding to the grating pattern of the MEB is formed. When incident light LI is guided from the end face of the optical waveguide D into its inside, the incident light LI is deflected by the grating pattern G with the high refractive index which is formed in the optical waveguide D and projected as outgoing light LO changed at its direction.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to an optical functional device using an optical waveguide having functions such as light transmission, condensation, imaging, and branching, and particularly to a solid-state electron beam source. This relates to the optical deflection element used.

C. Prior Art] Charged particles such as electrons and holes can arbitrarily and easily change their orbits from the outside using an electric field or a magnetic field. However, controlling electrically neutral light flux is not as easy as controlling charged particles.

2. Description of the Related Art As an optical deflection element, which is one of the elements for controlling a light flux, those using an electro-optic crystal and those using an optical waveguide have been known. In the case of using the former electro-optic crystal, a large quantity of inexpensive electro-optic crystal with good homogeneity and low optical loss must be supplied, and it cannot be said to be a very promising optical deflection element.

On the other hand, there are various types of optical waveguides in the latter category, from optical fibers used on ships to thin film waveguides, but there is no known one whose function can be changed arbitrarily from the outside.For example, a medium that allows light to pass through. There are optical deflection elements with a structure in which a piezoelectric thin film transducer, which is a diffraction grating with periodic refractive index changes, is attached to an ultrasonic medium, and an optical deflection element in which an interdigital transducer is installed on an optical waveguide substrate. As is known, in any case, the range in which Bragg reflection of a light beam can be performed by Bragg diffraction is limited to a very narrow range that satisfies the Bragg condition. The same applies to other various optical deflection elements, and the deflectable range is limited by each optical deflection element.
Multifunctional optical deflection elements have not yet been put into practical use.

[Object of the Invention] An object of the present invention is to provide an optical deflection element that functions as an optical functional element having various functions by using a solid-state electron beam source that generates a grating-shaped electron beam.

[Summary of the Invention] The gist of the present invention to achieve the above-mentioned object is to provide an optical waveguide made of a translucent strongly hyperelectric material, and an optical waveguide facing the optical waveguide and irradiated with an electron beam onto the optical waveguide to generate gray light. The present invention is an optical deflection element characterized by having a solid-state electron beam source that generates a ting-like refractive index pattern.

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

FIG. 1 is a schematic diagram of an embodiment of the present invention.

A planar optical waveguide made of ferroelectric material is provided on the substrate S, and a solid-state electron beam source ME is provided opposite to this optical waveguide.
B is placed. The incident light Ll can enter the end face of the optical waveguide.

The solid-state electron beam source MEB generates an electron beam flux EEI having a grating-like pattern using a plurality of electron beams. In the optical waveguide facing the solid-state electron beam source xEB, negative charges are generated corresponding to the electron beam EB irradiated from the solid-state electron beam source MEB. Electron flux E in optical waveguide
The ferroelectric portion irradiated with B causes a change in refractive index due to the charge, forming a grating pattern G with a high refractive index corresponding to the grating pattern of the solid-state electron beam source MEB.

When the incident light Ll is guided inside from the end face of the optical waveguide, if the grating pattern G formed as described above is formed in the optical waveguide, the incident light LI will be guided inside the optical waveguide. The light is deflected by a grating pattern G having a high refractive index within the beam, and is emitted as an emitted light LO whose direction has been changed. Of course, when the electron beam EB is not irradiated from the solid-state electron beam source MEB, the grating pattern G
is not formed, and the guided incident light LI also travels straight without being deflected.

By the way, as the electron beam generating element of the solid-state electron beam source WEB, for example, Japanese Patent Publication No. 54-30274 and Japanese Patent Application Laid-Open No. 54-1
No. 11272, JP-A-56-15529, JP-A-57-
The elements disclosed in Japanese Patent No. 38528 and the like can be used. These methods generate electrons within the semiconductor substrate by supplying a reverse voltage to the pn junction in a semiconductor substrate having a pn junction to cause electron avalanche multiplication, and transfer those electrons to the semiconductor substrate. It is designed to be released from the surface to the outside.

In the solid-state electron beam source WEB, such solid-state electron beam generating elements are appropriately arranged so as to draw a grating pattern, and each solid-state electron beam generating element can be independently controlled by applying a voltage appropriately. Can be driven. Therefore, it is possible to appropriately control each electron beam generating element to generate a desired grating-shaped electron beam EB. Incidentally, the incident light Ll may be white light, but light generated from a laser diode, LED, etc. is often used, and the material for forming the optical waveguide is L.
A thin film such as iNbo3 (lithium niobate) or PLZT is used. Furthermore, between the solid-state electron beam source WEB and the optical waveguide path, 10-
It is necessary to maintain a vacuum level of 3 torr or less,
More preferably, it is 10 −5 tarr or less.

Below, a second explanation will be given of how light is deflected and focused by the grating pattern obtained by the device of the present invention.
The device of the present invention shown in the two examples shown in FIG. 3 and FIG. Nor.

Figure 2 shows an example in which a linear grating pattern C1 is generated in an optical waveguide by a solid-state electron beam source WEB, and the incident light Ll guided into the optical waveguide is shaped like a grating pattern with a high refractive index. Light deflection is achieved by deflecting with pattern G1 to form output light LO. In addition, when forming the grating pattern G1, the dot spacing of the solid-state electron beam element that generates the grating-like electron beam EB is 0.1 to 0.2 pm, which is shorter than the wavelength of light.
degree is suitable.

FIG. 3 shows an example in which a curved grating pattern G2 is generated on an optical waveguide by a solid-state electron beam source MEB, and the incident light Ll guided into the optical waveguide as in the previous example is The outgoing light LO is deflected by a curved grating-like pattern G2 so as to focus on the focal point S.
It is designed to focus light on Note that the dot spacing of the solid-state electron beam generating element is 0.1 to 0 as in the above example.
．． Approximately 2 gm is suitable.

[Effects of the Invention] As explained above, the optical deflection element according to the present invention can form a desired high refractive index grating pattern in an optical waveguide using a solid-state electron beam source that generates a grating-shaped electron beam. By controlling the grating pattern appropriately, the light beam can be deflected in any direction, and it is also possible to select whether or not to deflect the light depending on whether or not to irradiate the electron beam. .

[Brief explanation of the drawing]

The drawings show an embodiment of the optical deflection element according to the present invention, and FIG. 1 is a schematic configuration diagram thereof, FIG. 2 is a plan view of a linear high refractive index grating pattern formed on an optical waveguide, and FIG. FIG. 3 is a plan view of a curved high refractive index grating-like pattern. Symbol WEB is a solid-state electron beam source, G is a grating pattern, and D is an optical waveguide. Figure 1 M2 figure

Claims (1)

[Claims] 1. An optical waveguide made of a transparent ferroelectric material, and a solid-state electron beam facing the optical waveguide and irradiating the electron beam onto the optical waveguide to generate a grating-like refractive index pattern. 1. An optical deflection element comprising a source. 2. The light deflection element according to claim 1, wherein the refractive index pattern is a linear pattern. 3. The light deflection element according to claim 1, wherein the refractive index pattern is a curved pattern.