JP2992407B2 - High power optical pulse generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical loop comprising a rare earth-doped optical fiber, an optical fiber for generating stimulated Raman, an optical splitter, and an optical switch. This is for a high-power optical pulse generator to be generated.

[0002]

2. Description of the Related Art The construction of a conventional high-output optical pulse generator will be described with reference to FIG. In FIG. 2, 8 is a high-output pulse YAG laser, 5 is an optical fiber for generating stimulated Raman, and 9 is a filter for selecting a wavelength. The optical fiber 5 for generating stimulated Raman includes, for example, P ₂ O ₅ -doped fiber or S
An iO ₂ -based optical fiber or the like can be used. YA
When a high-power light pulse of the G laser 8 is incident on the stimulated Raman generation optical fiber 5, the light shifted to the longer wavelength side by the interaction with each molecule contained in the stimulated Raman generation optical fiber 5 due to the stimulated Raman scattering phenomenon. Occurs, and is selected by the wavelength selection filter 9 and taken out.

[0003]

According to FIG. 2, a high-power pulse light can be obtained, but a light source for generating a high-power pulse light and a fiber for generating stimulated Raman are separately required. , These combinations affect the efficiency of the overall system.

An object of the present invention is to provide an efficient high-output optical pulse generator by forming an optical loop with a rare earth-doped optical fiber, an optical fiber for generating stimulated Raman, an optical splitter, and an optical switch. Japanese Patent Application No. 3-197337 discloses a high-power optical pulse generator using an optical loop.

[0005]

In order to achieve this object, according to the present invention, the output of the excitation light source 1 is connected to a multiplex input terminal 2.
An optical multiplexer 2 as an input of B, an isolator 3 which receives an output of the optical multiplexer 2 as input, and limits an oscillation direction, and a rare earth-doped optical fiber 4 which is excited by an output of the isolator 3;
The output of the rare-earth-doped optical fiber 4 is used as input, and the stimulated Raman generating optical fiber 5 for generating stimulated Raman light is used as the input terminal 6A, and the optical output is output from the branch output 6B. An optical splitter 6 to be taken out;
An optical switch 7 connected between the branch output terminal 6C of the optical branching device 6 and the multiplexing input terminal 2A of the optical multiplexer 2 is provided. Generate a scattered light pulse.

[0006]

Next, the configuration of a high-output optical pulse generator according to the present invention will be described with reference to FIG. 1 is an excitation light source, 2 is an optical multiplexer, 3 is an isolator, 4 is a rare earth-doped optical fiber, 7 is an optical switch, and an optical fiber 5 for generating stimulated Raman is the same as that in FIG.

The optical multiplexer 2 uses the output of the pump light source 1 as the input of the input terminal 2B, and the isolator 3 limits the traveling direction of the oscillating light generated in the loop. Rare earth doped optical fiber 4
Is excited by the output of the isolator 3, and the stimulated Raman generating optical fiber 5 receives the output of the rare-earth-doped optical fiber 4 as input and generates stimulated Raman light.

The optical splitter 6 splits the oscillating light and the stimulated Raman light generated in the loop, and extracts the output from the split output terminal 6B. The optical switch 7 is a branch output terminal 6C of the optical branching device 6.
And the input terminal 2A of the optical multiplexer 2. That is, FIG. 1 shows that an optical loop is formed by the rare earth-doped optical fiber 4, the optical fiber for generating stimulated Raman 5, the branching device 6, and the optical switch 7, and the optical switch 7 is brought into contact for a short time, so that a high-output Generate a scattered light pulse.

The optical switch 7 of FIG. 1 may be connected between the output of the stimulated Raman generating optical fiber 5 and the input terminal 6 A of the optical splitter 6. The optical switch 7 may be connected between the output of the rare earth-doped optical fiber 4 and the input of the stimulated Raman generating optical fiber 5.

The stimulated Raman generating optical fiber 5 receives the output of the rare earth doped optical fiber 4 as input and generates stimulated Raman scattering. Assuming that the wavelength of the excitation light source is 1.48 μm and the rare-earth-doped optical fiber 4 is an Er ³⁺ -doped optical fiber, the wavelength of the original oscillation in the loop is 1.553 μm, and the inserted guided Raman generating optical fiber 5 is made of a non-doped SiO ₂ fiber. Assuming a standard fiber, the peak wavelength of stimulated Raman scattering
It becomes about 90 cm ^-1 , and a high-output optical pulse is obtained in the vicinity of 1.650 μm, and is extracted from the output end 6B of the optical branching device 6. The optical splitter 6 may be a splitter having an n-to-1 splitting ratio, but is preferably a wavelength separation type splitter (WDM).

[0011]

According to the present invention, an optical loop is composed of a rare-earth-doped optical fiber, an optical fiber for generating stimulated Raman, an optical splitter, and an optical switch, and light for generating stimulated Raman that generates induced Raman in the optical loop. Since a fiber is built in, a high-power optical pulse generator that efficiently generates stimulated Raman can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a high-output optical pulse generator according to the present invention.

FIG. 2 is a configuration diagram of a high-output optical pulse generator according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Excitation light source 2 Optical multiplexer 3 Isolator 4 Rare-earth-doped optical fiber 5 Optical fiber for induced Raman generation 6 Optical splitter 7 Optical switch

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masaaki Furuhashi 4-19-7 Kamata, Ota-ku, Tokyo Inside Ando Electric Co., Ltd. (72) Inventor Tsuneo Horiguchi 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Telephone Co., Ltd. (72) Inventor Toshiya Sato 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (56) References JP-A-3-136391 (JP, A) (58) Fields investigated (Int.Cl. ⁶ , DB name) G02F 1/35-1/35 502 H01S 3/30 JICST file (JOIS) WPI (DIALOG)

Claims (3)

(57) [Claims] An optical multiplexer (2) having an output of an excitation light source (1) as an input of a first multiplexer input terminal (2B); an output of the optical multiplexer (2) as an input; For the stimulated Raman generation, which receives the isolator (3) to be limited, the rare-earth-doped optical fiber (4) pumped by the output of the isolator (3), and the output of the rare-earth-doped optical fiber (4) to generate stimulated Raman light Connect the output of the optical fiber (5) and the optical fiber for stimulated Raman generation (5) to the input terminal (6A)
And an optical splitter (6) for extracting an optical output from the first split output (6B); a second split output terminal (6C) of the optical splitter (6); Optical switch connected between the multiplexing input terminals (2A)
(7) A high-power optical pulse generator characterized in that a high-output stimulated Raman-scattered light pulse is generated by bringing the optical switch (7) into contact for a short time. 2. The high-power optical pulse according to claim 1, wherein the optical switch is connected between the output of the stimulated Raman generating optical fiber and the input terminal of the optical splitter. Generator. 3. The optical switch (7) is a rare-earth-doped optical fiber.
2. The high-power optical pulse generator according to claim 1, wherein the high-output optical pulse generator is connected between the output of (4) and the input of the stimulated Raman generating optical fiber (5).