JPS6254986A - Light amplifying element - Google Patents

Abstract

PURPOSE:To reduce the size and to raise an integration by forming a clad unit around a core for guiding an outer pumping light, and arranging a plurality of light emitting units in the clad unit. CONSTITUTION:A pumping light fiber 6 is connected to guide pumping light to the end face having no reflecting film of a core unit 1. The fiber 6 uses mainly a large bore quartz optical fiber having 100-200mum of core diameter to guide the high power light. The core unit 1 of a light amplifier is not provided, is formed in a hollow shape in this portion, the core of the fiber 6 can be inserted without gap, and the core at the end of the fiber 6 is used also as the core unit 1 of the light amplifier. One ends of input single mode optical fibers 7... for guiding an input light are connected with the end face formed with high reflecting films 4 of the light emitting units 3..., and the other end is connected with an input light source. Thus, a plurality of lights can be simultaneously amplified and integrated to reduce the size.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an optical amplification device, and particularly to an optical amplification device for a fiber shop that is compact and can be integrated.

[Prior art and its problems]

For optical amplification, laser oscillation devices using external pumping such as glass lasers and gas lasers, semiconductor lasers using injection lasers, and the like have been used.

However, glass lasers, gas lasers, and the like have drawbacks in that it is difficult to miniaturize the device, and it is also difficult to integrate them to amplify a large number of lights at the same time. Also,
Semiconductor lasers have the disadvantage that their output is small and coupling with optical fibers is poor.

[Means for solving problems]

Therefore, in this invention, by providing a cladding St around a core body that guides external bombing light and arranging a plurality of light emitters in the cladding body, miniaturization and integration are possible.
It has a large output and can be easily connected to optical fiber.

FIG. 1 shows an example of the optical amplifying element of the present invention.
Reference numeral 1 in the figure is a core body. This core body 1 is for guiding a pumping source from an external light source, and here it is a cylindrical body with a diameter of 100 to 200 μrn and a length of 0.5 to 10116 degrees. The core body 1 is made of multicomponent glass, quartz glass, or the like, which has a higher refractive index than the surrounding cladding body 2 . A cylindrical cladding body 2 is integrally provided around the core body 1.

The cladding body 2 has a refractive index lower than that of the core body 1 and is a multicomponent material containing oxide crystal materials such as ruby, YAG, and alexandrite, and oxides such as alkali metals, alkaline earth metals, aluminum, and boron. It is made of glass or the like, and its length is the same as that of the core body 1.

Furthermore, the cladding body 2 includes a small diameter cylindrical light emitting body 3.
A plurality (four in this case) are buried at equally spaced positions on the circumference so that their central axes are parallel to the axial direction of the core body l. The diameter of the light emitters 3 is about 2 to 10 μm, and the diameter is selected to match the core diameter of the single mode optical fiber connected to the light emitters 3 to guide input and output light. Talented. Its length is the same as that of the core body 1 and the cladding body 2.

This luminous body 3 is made of Cr-ruby, Nd-YAG, Nd-
YIG, Nd-LiNb0. , Nd-LiTa0. The material is made of a laser medium capable of population inversion, such as a crystalline material such as Nd-4 component glass, and a material having a higher refractive index than the cladding material 2 is used.

And core body 1. Cladding body 2 and luminous body 3...
A high reflection film 4 made of a gold evaporated film or the like having a reflectance of about 98 to 99% is formed on one end face of a cylindrical aggregate composed of Low reflection Bj8 consisting of a force of 1, such as a gold evaporated film of about 95% lower than
5 is formed. These two reflections I! *4 and 5 are parallel to each other and 1.

Note that no reflective film is provided on the shoulder surface of the core body 1 on the side where the pumping light is input.

Next, a method of using such an optical amplifying element will be explained with reference to FIG. 2.

First, the pumping optical fiber 6 for guiding the pumping light is connected to the base surface of the core body 10 having no reflective film. As the optical fiber 6 for bombing, a large-diameter quartz optical fiber with a core diameter of 100 to 200 μm is mainly used so that high-power light can be guided. Alternatively, it is also possible to leave this part hollow without providing the core body l of the optical amplification element 4, and insert the core of the pumping optical fiber 6 into this hollow part without leaving a gap. The core at the end of 6 is the light layer rll! It will also serve as Yuko's core body 1.

Drill a hole in which 3... will be accommodated. Next, the columnar glass base material that will become the luminous body 3 is inserted into the hole in which the luminous body 3 is to be accommodated, and then rolled under heat to form a rod of a predetermined diameter, which is then cut into a predetermined length. However, after optically polishing the end face, a reflective film is provided, and finally, the core of the bombing optical fiber is inserted into the cavity in which the core body 1 is to be accommodated, to obtain an optical amplifying element.

In such a light layer @ element, by arranging a plurality of light emitting bodies 3 in the cladding body 2, it is possible to amplify a plurality of lights of different wavelengths at the same time, so-called integrated integration. It is also possible to make the shape smaller. In addition, input and output optical fibers 7..., 8...
・The connection surface is also large.

Since it is flat, it can be easily carried out, and the coupling efficiency is also good. Furthermore, high output can be easily obtained by increasing the input of pumping light.

〔Example〕

(Example 1) A sapphire fiber that becomes a cladding body having an end-to-end shape as shown in FIG. 3 was grown by the EFG method using a molybdenum sash die. A Nd-YAG single crystal was grown in the hole in which the light emitter was accommodated by the horizontal Bridgeman method. This fiber was cut into lengths of 10 cm, the end faces were polished parallel to each other, and one end face was coated with a low reflective film with a reflectance of 95%, and the other end face was coated with a high reflective film with a reflectance of 98 cm. Steam 71
It was formed from il. A fiber diameter of 250 μm for bombing is placed in the cavity where the core body is placed in the center, and a core g
The core of a Stepf index optical fiber with =200 μm and Δ=1.5% was exposed and inserted to form an optical amplification element.

Six single mode optical fibers each having a core diameter of 6 μm and a fiber diameter of 125 μm were connected to both end faces of each light emitting body of this optical amplification element.

The original input fiber is connected to an injection-type InGaAs laser (wavelength 1
．． 06μm, output 39mW) is 6i1! It was connected to the output end of the integrated multiplication semiconductor laser, and the pumping optical fiber was connected to a Ne-Ha gas laser (wavelength: 0.633 μm), so that pumping light was input into the core body.

Then, the output of the Ne-)1e gas laser is increased to several W to excite the light emitting body, and in this state, when a pulse of laser light is input from the integrated semiconductor laser, the light emitter has a wavelength of 1.06 μm and an output of 950 mW. Pulsed light was output.

(Example 2) A hole with a diameter of 20,111 mm was drilled in the center of a cylindrical base material made of calcium aluminate glass (diameter 40 m), and eight holes with a diameter of 0.5 tn were bored in the peripheral area by polishing.

The diameter 20 dragon hole accommodates a glass base material with a graded index type distribution of Δ=O, S S, and the diameter 0.5
A glass base material made of Nd-calcium aluminate glass with a Δ-thickness of 0.3 was housed in the hole, and this was rolled to form a fiber having an end face structure as shown in FIG. Next, this fiber was cut to a length of 30 mm, both end faces were optically polished, a reflective film was formed in the same manner as in Example 1, and similar input/output optical fibers were connected to both end faces of the light emitter.

The input optical fiber was connected to eight integrated semiconductor lasers (wavelength 0.86 μm, output 100 mW), and the core body was connected to a large-diameter multicomponent optical fiber with a fiber diameter of 250 μm and a core diameter of 200 μm, and a xenon lamp was connected. Pumping light was guided to bring one light emitter into an excited state. When pulsed light from an integrated semiconductor laser is input, an image is fired and the wavelength is 0.8.
Pulsed light with a diameter of 6 μm and an output of 1.5 W was output.

〔Effect of the invention〕

As explained above, the optical amplifying element of the present invention has a cylindrical cladding body provided around a columnar core body that guides pumping light, and a plurality of light emitters arranged on this cladding body. , it is possible to amplify multiple lights at the same time,
Integration is possible and miniaturization can be achieved.

Furthermore, connection with input/output optical fibers is easy, and the coupling efficiency is good. Furthermore, high output can be obtained despite the small size.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of the optical layer 1'@device of the present invention, FIG. 2 is an explanatory diagram showing how to use the optical amplification device of the present invention, and FIGS. 3 and 4 are examples of the present invention. FIG. 2 is a front view showing the dimensions and shape of the optical amplification elements obtained in Examples 1 and 2. 1... Core body, 2... Clad body, 3
・River: Luminous body.

Claims (1)

[Claims] A cylindrical cladding body having a lower refractive index is provided around a cylindrical cladding body having a lower refractive index around a cylindrical core body having a high refractive index that guides the pumping light, and a plurality of cylindrical light emitters are arranged within this cladding body. optical amplification element.