JPH1184148A - Aspherical fiber bundle optics - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to transmit light of a large area by free routes with low loss and to condense and disperse light with free wave fronts without combining plural optical elements by working the end faces of a fiber bundle formed by bundling plural pieces of optical fibers to an aspherical shape. SOLUTION: The end face 3 or both end faces of the fiber bundles 2 formed by regularly or randomly bundling plural pieces of the optical fibers 1 contg. any among quartz glass, multicomponent glass and plastic as an essential component are ground to the aspherical shape and is then polished. As a result, the transmission of the light of the large area in the free routes with the low loss is made possible, the wavelengths, intensity and phases of the respective light rays may be changed with lapse of time and the incident luminous fluxes may be condensed and diverged at the free wave fronts without combining the plural optical elements. The irradiation with the discrete luminous fluxes is made possible and the respective light rays may be changed in the wavelengths, the intensity and the phases with lapse of time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical element using an optical fiber.

[0002]

2. Description of the Related Art With the rapid progress of the information society in recent years, the role of light has been diversified. Light was originally used to illuminate objects, but today it is used for transmitting information and images, various sensors, and even various analyzers and treatments for diseases. It is thought to go.

When trying to use light for various purposes,
A tool for freely manipulating light is called an optical element. There are various types of optical elements, and typical examples include a lens, a mirror, a diffraction grating, and an optical fiber.

[0004] A lens has a function of condensing and diverging light by utilizing the refraction phenomenon of light. At the time when processing technology was not developed, lenses were mainly spherical lenses, but with the advent of numerically controlled ultra-precision processing machines, aspherical lenses that can handle the wavefront of light with more flexibility have been developed with high precision. It is now possible to process it into many optical systems.

[0005] The mirror has a function of changing the course of light by utilizing the light reflection phenomenon, and condensing and diverging light in the same manner as a lens. Light having a relatively short wavelength cannot be refracted using a lens, and in such a case, a reflecting optical system using a mirror may be designed. Previously, mirrors were generally flat or spherical mirrors, but aspheric mirrors are now increasingly used.

[0006] Diffraction gratings can collect, diverge, and disperse light using the diffraction phenomenon of light, and are used as multifocal optical elements and spectroscopes.

[0007] Optical fibers can be used to transmit light with low loss by totally reflecting light at the boundary between two kinds of materials having different refractive indices. Further, since the optical fiber is thin and plastic (flexible), light can be transmitted through a free path.

[0008] A fiber bundle in which a plurality of optical fibers are bundled is used for illumination and image transmission because it can have a large area in addition to the properties of optical fibers.

[0009]

In the above-mentioned conventional optical element, for example, in order to transmit light of a large area with a free path with low loss and to collect and diverge with a free wavefront, it is necessary to use a plurality of optical elements. It was necessary to combine optical elements. However, when a plurality of optical elements are combined, the size of the optical system itself becomes large, and complicated operations such as optical axis alignment have to be performed.

The present invention has been made to solve the above-mentioned problems. That is, the object of the present invention is:
An object of the present invention is to provide an optical element capable of transmitting light of a large area through a free path with low loss without combining a plurality of optical elements, and capable of collecting and diverging light with a free wavefront.

[0011]

According to the present invention, there is provided an aspherical fiber bundle optical element in which an end surface of a fiber bundle in which a plurality of optical fibers are bundled is processed into an aspherical surface.

According to a preferred embodiment of the present invention, the optical fiber contains any one of quartz glass, multi-component glass and plastic as a main component. The fiber bundle has a plurality of optical fibers bundled regularly or randomly, and one or both end faces are processed to be aspherical.

By using the above-mentioned aspherical fiber bundle optical element of the present invention, a large area light can be transmitted through a free path with low loss without combining a plurality of optical elements, and a free wavefront can be collected.・ Can diverge.

Further, by using the aspherical fiber bundle optical element of the present invention, it is possible to irradiate a discrete light beam, and each light can change its wavelength, intensity and phase over time. In addition, these light beams can be collected and diverged.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of an aspherical fiber bundle optical element according to the present invention. As shown in this figure, the aspherical fiber bundle optical element of the present invention is an optical element in which an end face 3 of a fiber bundle 2 in which a plurality of optical fibers 1 are bundled is processed into an aspherical surface.

The optical fiber 1 preferably contains any of quartz glass, multi-component glass and plastic as a main component. Quartz glass and multi-component glass are generally hard and brittle materials and are difficult to machine by cutting. An aspheric shape is mainly created by grinding, and a mirror surface is obtained by polishing. Plastic can be cut, but when the work material is used especially as an optical element,
The regular cutting marks may serve as a kind of diffraction grating, which may adversely affect the optical characteristics. On the other hand, grinding does not cause such a problem because random machining marks remain, but mirror grinding is difficult with general grinding,
ELID grinding method (Electrolytic In-Process Dressing)
Good.

The fiber bundle 2 has a plurality of optical fibers 1 bundled regularly or randomly.
One end face 3 or both end faces are processed to be aspherical.

By utilizing the above-described aspherical fiber bundle optical element of the present invention, a large area light can be freely transmitted by a fiber bundle 2 in which a plurality of optical fibers 1 are bundled without combining a plurality of optical elements. The fiber bundle 2 can be transmitted with low loss, and the wavelength, intensity, and phase of each light can be changed over time.
Is processed into an aspherical shape, so that the incident light beam can be focused on a free wavefront. Further, the light can be collected and diverged at a free wavefront.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example in which aspherical surface processing of a plastic fiber bundle is performed by using an ELID grinding method will be described below.
A commercially available plastic fiber bundle φ5 mm (fiber diameter φ0.5 mm × 80) was fixed to a jig, and the tip was processed into an axisymmetric aspherical shape by a biaxially controlled aspherical processing machine. The opposite end face (end) of the fiber bundle was inserted into a hole provided in a plastic plate, fixed with an adhesive, and processed into a flat surface by ELID lap grinding.

It has been observed that when light is incident from the end processed into a flat surface, the light is emitted while being collected from the end processed into the opposite convex shape. In addition, light was selectively incident on the central portion and the outer peripheral portion of the fiber bundle, and the state of each emission was observed, and the basic characteristics of the aspherical fiber bundle optical element were confirmed.

It should be noted that the present invention is not limited to the above-described embodiments and examples, and it is needless to say that various changes can be made without departing from the spirit of the present invention.

[0022]

As described above, the aspherical fiber bundle optical element of the present invention can transmit a large area light with a free path and a low loss without combining a plurality of optical elements, and has a free wavefront. It has excellent effects such as being able to condense and diverge. Furthermore, the optical element of the present invention can transmit a large area of light through a free path with low loss, and can diverge and condense the light. Application as an image element is conceivable. Further, the present invention can be applied to various sensors and the like by utilizing the feature that light having an arbitrary wavelength, intensity, and phase can be incident on each optical fiber and collected.

[Brief description of the drawings]

FIG. 1 is a schematic view of an optical element according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Fiber bundle 3 Fiber bundle end face 4 Incident light 5 Condensed light

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Osamu Omori 2-1 Hirosawa, Wako-shi, Saitama Pref. RIKEN (72) Inventor Takeo Nakagawa 2-1 Hirosawa, Wako-shi Saitama Pref.

Claims (4)

[Claims] 1. An aspherical fiber bundle optical element, wherein an end surface of a fiber bundle in which a plurality of optical fibers are bundled is processed into an aspherical surface. 2. The aspherical fiber bundle optical element according to claim 1, wherein the optical fiber contains any one of quartz glass, multi-component glass, and plastic as a main component. 3. The aspherical fiber bundle optical element according to claim 1, wherein the fiber bundle has a plurality of optical fibers bundled regularly or randomly. 4. The aspherical fiber bundle optical element according to claim 1, wherein one or both end faces of the fiber bundle are processed into an aspherical surface.