JPS6064313A - Optical fiber with lens - Google Patents

Abstract

PURPOSE:To eliminate the need for an optical axis adjustment and a distance adjustment by fitting a microlens atop of an optical fiber and making projection light into a parallel light beam. CONSTITUTION:An end surface of the optical fiber 7 is set at the focal point of the microlens 8, and the projection light from the optical fiber 7 is made into the parallel light beam. This optical fiber 7 is put opposite to a lens 13 provided atop of an optical fiber 12 having the same structure by using a screw 11 cut in a holder 9 and a connector 16. Consequently, a slight shift in optical axis position between the optical fibers 7 and 12 and variations in the distance between the lenses 8 and 13 are disregarded and the coupling of the optical fibers is facilitated. The optical power coupling between a photodetector and a light emitting element and the wiring of an optical transmission line are rationalized.

Description

Detailed Description of the Invention (Technical Field) The present invention eliminates the need for optical axis adjustment, distance adjustment, etc., which are problems when optical power is coupled between optical fibers, or between optical fibers and a photodetector, or between an optical 7-eyeper and a light emitting element, etc. This relates to a method for achieving this.

(Prior art and its problems) For example, when connecting optical fibers, a lens 3 is inserted between the optical fibers as shown in Figure 1, and the light emitted from the fiber 1 on the light transmitting side is focused on the end face of the fiber 2 on the light receiving side. There is a way to shine. At this time, it is necessary to adjust the optical axes 4 and 5 of both optical fibers, the optical axis 6 of the lens, and the distances la and b between the lens and the optical fiber. Since it is necessary to make fine adjustments while observing, it has the disadvantage of very poor operability. In addition to this, there is a method of directly connecting the end faces of both optical fibers without using a lens, but this also requires adjustment of the optical axes 4 and 5.

On the other hand, the present invention (structure of the invention) An object of the present invention is to eliminate such drawbacks and provide an optical fiber with high operability in optical power coupling.

Embodiments of the present invention will be described below based on the drawings.

In FIG. 2, the end face of the optical fiber 7 is set at the focal point of the microlens 8 to make the light emitted from the optical fiber parallel. By connecting the thus produced optical fiber to another optical fiber using a screw 11 cut into the holder 9, highly efficient coupling of optical power can be achieved. That is, as shown in FIG. 3, the optical axes 17, 1 of both optical fibers
Even if 8 does not match, the light beams between the lenses 8 and 13 are parallel, so all the light beams that have passed through the lens 13 are incident on the focal point, the core of the optical fiber 12. Therefore, there is no problem with the deviation of the optical axis due to screw fixation or the accuracy of the distance C between the lenses. In order to realize such an optical fiber, since the optical fiber itself has a small diameter, the lenses 8 and 13 need to be small in diameter and lightweight.

In one specific embodiment of FIG. 2, the diameter of the plastic coating of the optical fiber 5 and the holder 9 is 0.9 mm, while the microlens 8, 13
The diameter was set to 0.5 mvt, and much better results were obtained compared to the conventional one.

(Effects of the Invention) According to the present invention, there is no need for adjustment work in optical power coupling between optical fibers or between optical fibers and a photodetector/light emitting element as in the past, so, for example, when wiring an optical data transmission circuit, etc. Very efficient.

[Brief explanation of the drawing]

FIG. 1 shows a conventional method of optical power coupling between optical fibers, FIG. 2 shows an embodiment of a lensed optical fiber according to the present invention, and FIG. 3 shows two optical fibers to be connected in the present invention. A light flux diagram when the optical axis of the fiber is shifted is shown. 1.7 e... Light transmitting side optical fiber (core + cladding) 2.12 ...... Light receiving side optical fiber (core + cladding)
Cladding) 3... Lens 8.13 ・Φ... Microlens attached to the optical fiber 4.17 ...... Optical axis of the optical fiber on the transmitting side 5.18 ...... Receiving side optical fiber optical axis 6
・・・・・・Optical axis of lens

Claims (1)

[Claims] A lensed optical fiber characterized by having a microlens attached to the tip so that the emitted light is parallel.