TWI446081B - Transversely pumping fiber amplifier - Google Patents

Description

Lateral optical fiber amplifier

The present invention relates to an optical fiber amplifier, and more particularly to a fiber amplifier for a lateral optical pump.

Referring to FIG. 1 , a conventional optical fiber amplifier 500 is disclosed in the prior art. The optical fiber amplifier 500 includes a gain fiber 510, a plurality of grating units 520, a reflective layer 530, and a semiconductor laser. 540, the grating unit 520 is disposed on one side of the gain fiber 510, and the reflective layer 530 is disposed on the grating unit 520. The semiconductor laser 540 is disposed on the other side of the gain fiber 510 and corresponds to The grating unit 520 is configured to emit a pump light 541. The pump light 541 generates a diffracted light by the grating unit 520, and the diffracted light can be reflected in the gain fiber 510. However, the fiber amplifier 500 system cannot effectively enhance the diffracted light in the gain fiber 510, so the gain medium of the gain fiber 510 has a poor absorption efficiency for the diffracted light.

A side optical pump fiber amplifier comprising a gain fiber, a pump source, and a first reflective layer and a second reflective layer, the gain fiber having a first end face and a first end corresponding to the first a second end surface of the end surface and a light irradiation area between the first end surface and the second end surface, the pump light source is disposed on one side of the gain fiber, and generates a pump light, the pump light The light-irradiating area of the gain fiber is irradiated, and the first reflective layer and the second reflective layer are respectively formed on the first end surface and the second end surface of the gain fiber, and reflect the pump light. In the present invention, the pump light generated by the pumping light source is incident on the side of the gain fiber and the first reflective layer and the second reflective layer both have high reflectivity, when the pump light is in the first reflection When the layer and the second reflective layer propagate back and forth, the gain medium of the gain fiber can effectively absorb the pump light to obtain a fiber amplifier with high efficiency of the lateral light pump.

Referring to FIG. 2, which is a preferred embodiment of the present invention, a lateral optical fiber amplifier 10 includes a gain fiber 11, a pump source 12, and a first reflective layer 13 and a second. a reflective layer 14 having a first end surface 11a, a pair of second end surfaces 11b corresponding to the first end surface 11a, and a light irradiation region 11c between the first end surface 11a and the second end surface 11b. The pump light source 12 is disposed on one side of the gain fiber 11 and generates a pump light 121 that illuminates the light irradiation region 11c of the gain fiber 11. In this embodiment, the pump light source 12 The pumping source 12 can be a semiconductor laser array. The first reflective layer 13 is formed on the first end surface 11a of the gain fiber 11. The second reflective layer 14 is formed on the second end of the gain fiber 11. The first reflective layer 13 and the second reflective layer 14 are formed by a coating method. The first reflective layer 13 and the second reflective layer 14 have high reflectivity and reflect the pump light 121.
Referring to FIG. 2 again, in the embodiment, the optical amplifier 10 of the lateral optical pump further includes a collimating lens 15 disposed on the pumping source 12 and the gain fiber 11 The collimator lens 15 can be used to introduce the pump light 121 into the gain fiber 11 in a collimated manner. In this embodiment, the lateral optical fiber amplifier 10 further has a reflective grating 16 . The reflective grating 16 is attached to the light-irradiating region 11c of the gain fiber 11. In the embodiment, the gain fiber 11 and the reflective grating 16 further have an index-matching adhesive 17, which has a refractive index. The matching adhesive 17 has high transparency and is used for fixing the gain fiber 11 and the reflective grating 16. Referring to FIG. 3, the reflective grating 16 has a substrate 161 and a grating structure 162 formed on the substrate 161. And a metal layer 163 covering the grating structure 162. In the embodiment, the material of the metal layer 163 is gold, which can improve the reflectivity of the pump light 21. In this embodiment, the metal layer 163 is formed on the grating structure 162 by coating, when the pump light 121 is When the reflective grating 16 is reflected by the gain fiber 11 , the grating structure 162 of the reflective grating 16 can generate a large angle reflection, and the pump light 121 is introduced into the gain fiber 11 . The first reflective layer 13 and the second reflective layer 14 of the gain fiber 11 are reflected and propagated. In this embodiment, the first reflective layer 13 is parallel to the second reflective layer 14 The pump light 121 performs reflection propagation in the gain fiber 11 in the shortest path. In this embodiment, since the first reflective layer 13 of the gain fiber 11 is parallel to the second reflective layer 14 and the first reflective layer 13 and the second reflective layer 14 both have high reflectivity, When the pump light 121 is introduced into the gain fiber 11 for reflection propagation, the pump light 121 in the gain fiber 11 can be raised, so that the gain medium of the gain fiber 11 can effectively absorb the pump light 121 to obtain High efficiency of the lateral optical fiber amplifier 1 .
The scope of the present invention is defined by the scope of the appended claims, and any changes and modifications made by those skilled in the art without departing from the spirit and scope of the invention are within the scope of the present invention. .

10‧‧‧Side light optical amplifier
11‧‧‧Gain Fiber
11a‧‧‧ first end face
11b‧‧‧second end face
11c‧‧‧Lighting area
12‧‧‧Helping light source
121‧‧‧Help Puguang
13‧‧‧First reflective layer
14‧‧‧Second reflective layer
15‧‧‧ Collimating lens
16‧‧‧Reflective grating
161‧‧‧Substrate
162‧‧‧Grating structure
163‧‧‧metal layer
17‧‧‧Index matching adhesive
500‧‧‧Fiber Amplifier
510‧‧‧Gain Fiber
520‧‧‧Raster unit
530‧‧‧reflective layer
540‧‧‧Semiconductor laser
541‧‧‧Help Puguang

Figure 1: Schematic diagram of a known optical fiber amplifier for a lateral light pump.
Figure 2 is a schematic illustration of a side optical pump fiber amplifier in accordance with a preferred embodiment of the present invention.
Figure 3: A side cross-sectional view of a reflective grating of the optical amplifier of the lateral optical pump.

10‧‧‧Side light optical amplifier

11‧‧‧Gain Fiber

11a‧‧‧ first end face

11b‧‧‧second end face

11c‧‧‧Lighting area

12‧‧‧Helping light source

121‧‧‧Help Puguang

13‧‧‧First reflective layer

14‧‧‧Second reflective layer

15‧‧‧ Collimating lens

16‧‧‧Reflective grating

17‧‧‧Index matching adhesive

Claims (7)

A side optical fiber amplifier, comprising:
a gain fiber having a first end face, a second end face opposite the first end face, and a light irradiation zone between the first end face and the second end face;
a pump light source disposed on one side of the gain fiber and capable of generating a pump light, the pump light system illuminating the light irradiation area of the gain fiber; and a first reflective layer and a second reflection The layers are respectively formed on the first end surface and the second end surface of the gain fiber, and reflect the pump light. The optical amplifier of the lateral optical pump according to claim 1, further comprising a collimating lens disposed between the pumping source and the gain fiber. The optical amplifier of a lateral optical pump according to claim 1, wherein the first reflective layer is parallel to the second reflective layer. The optical amplifier of the lateral optical pump according to claim 1, further comprising a reflective grating attached to the light irradiation region of the gain fiber. The optical amplifier of a lateral optical pump according to the fourth aspect of the invention, wherein the reflective grating has a substrate, a grating structure formed on the substrate, and a metal layer formed on the grating structure, the metal The material of the layer is gold. The optical amplifier of the lateral optical pump of the fourth aspect of the patent application has an index matching adhesive, and the index matching adhesive is located between the gain fiber and the reflective grating. The fiber-optic amplifier of the lateral optical pump according to item 6 of the patent application scope has high transmittance.