WO2019205915A1

WO2019205915A1 - C+l waveband superfluorescence optical fiber light source

Info

Publication number: WO2019205915A1
Application number: PCT/CN2019/081513
Authority: WO
Inventors: 吴旭; 陈永路; 刘承香; 林哲明; 阮双琛
Original assignee: 深圳技术大学
Priority date: 2018-04-25
Filing date: 2019-04-04
Publication date: 2019-10-31
Also published as: CN108418087A; CN108418087B

Abstract

Disclosed is a C+L waveband superfluorescence optical fiber light source. The superfluorescence light source comprises a branch isolator, a broadband coupler, an erbium-doped optical fiber set, a wavelength division multiplexer and a pump laser. Pump light emitted by the pump laser is incident to the erbium-doped optical fiber set and excites the erbium-doped optical fiber set to generate forward C-waveband superfluorescence and backward C-waveband superfluorescence. The forward C-waveband superfluorescence is reversed after passing through the wavelength division multiplexer to re-excite an erbium-doped optical fiber in the erbium-doped optical fiber set to generate L-waveband superfluorescence. The broadband coupler couples the C-waveband superfluorescence and the L-waveband superfluorescence to obtain C+L waveband superfluorescence and transmits same to the outside via the branch isolator. In the present invention, the parallel-connection structure of an erbium-doped optical fiber set can be more conveniently used for making output C+L waveband superfluorescence have the characteristics of wide spectral width and high flatness by adjusting the length of an optical fiber. Furthermore, the superfluorescence optical fiber light source disclosed in the present invention does not require the filtering by a filter, and therefore, the superfluorescence optical fiber light source of the present invention further has the characteristic of low cost.

Description

C+L band super fluorescent fiber source

Technical field

The invention relates to a super fluorescent fiber light source, in particular to a C+L band super fluorescent fiber light source, belonging to the technical field of light sources.

Background technique

The super-fluorescence directly output from the existing C+L band (C-band: 1525nm - 1565nm, L-band: 1570nm - 1620nm) super-fluorescent fiber source does not have high flatness and wide spectral width, and achieves superfluorescence of output. With high flatness and wide spectral width, it also needs to filter the superfluorescence with a filter. Filtering the output of the superfluorescence will increase the cost, thus providing a high flatness and wide spectral width. At the same time, low-cost ultra-fluorescent fiber sources are urgently needed to be solved.

technical problem

In the existing ultra-fluorescent fiber light source, there is no high-flatness, wide spectral width, and low-cost super-fluorescent fiber light source for the C+L band superfluorescence of the output.

Technical solution

The main object of the present invention is to provide a C+L-band super-fluorescent fiber source, which aims to solve the problem that the existing C+L band superfluorescence has high flatness and wide spectral width in the existing super-fluorescent fiber source. At the same time, it has a low-cost super fluorescent fiber source.

To achieve the above object, the present invention provides a C+L-band super-fluorescent fiber source comprising: a branch isolator, a broadband coupler, an erbium-doped fiber group, a wavelength division multiplexer, and a pump laser; The erbium-doped fiber group is composed of at least two parallel erbium-doped fibers;

The branch isolator is connected to one end of the broadband coupler, and two optical ends of the broadband coupler are connected to one end of the erbium-doped fiber group, and the other end of the erbium-doped fiber group is connected to the wavelength division multiplexer;

The pump light emitted by the pump laser is incident on the erbium-doped fiber group, and the pump light excites the erbium-doped fiber group to generate a first-direction C-band super-fluorescence and a second-direction C-band super-fluorescence, the first direction being the The direction of the erbium-doped fiber group to the broadband coupler, the second direction is the direction of the erbium-doped fiber group to the wavelength division multiplexer; the second direction C-band super-fluorescence is reversed after the wavelength division multiplexer Re-exciting the erbium-doped fiber in the erbium-doped fiber group to generate a first-direction L-band superfluorescence, the broadband coupler coupling the first-direction C-band super-fluorescence and the first-direction L-band super-fluorescence to obtain a C+L-band super Fluorescence, the C+L band superfluorescence is transmitted outward through the branch isolator.

Optionally, the pump laser is connected to the first end of the branch isolator; the second end of the branch isolator is connected to one end of the broadband coupler; the C+L band superfluorescence passes through the third of the branch isolator The end is transmitted outward; the pump light from the pump laser is incident on the erbium-doped fiber group through the branch isolator and the broadband coupler.

Optionally, a pump laser is connected to the other end of the wavelength division multiplexer, and the pump light emitted by the pump laser is incident on the erbium-doped fiber group through the wavelength division multiplexer.

Optionally, the pump laser is coupled to the splitting light, and the first split end of the split coupler is connected to the first end of the branch isolator, and the second split end of the split coupler and the other part of the wavelength division multiplexer Connected at one end; the second end of the branch isolator is connected to one end of the broadband coupler; the C+L band superfluorescence is transmitted outward through the third end of the branch isolator;

The pump light emitted by the pump laser is divided into a first pump light and a second pump light through the splitting coupler, and the first pump light is emitted from the first splitting end, and is coupled to the broadband via the branch isolator The device is incident on the erbium-doped fiber group; the second pump light is emitted from the second beam splitting end, and is incident on the erbium-doped fiber group through the wavelength division multiplexer.

Optionally, the branch isolator, the broadband coupler, the erbium-doped fiber group, the wavelength division multiplexer, and the pump laser are connected by fiber fusion coupling.

Beneficial effect

The invention provides a C+L-band super-fluorescent fiber source, which comprises a branch isolator, a broadband coupler, an erbium-doped fiber group, a wavelength division multiplexer and a pump laser; a branch isolator and a broadband coupler One end is connected, the other end of the broadband coupler is connected to one end of the erbium-doped fiber group, and the other end of the erbium-doped fiber group is connected to the wavelength division multiplexer; the pump light from the pump laser is incident on the erbium-doped fiber group, and the pump is pumped The photoexcited erbium-doped fiber group produces a first-direction C-band superfluorescence and a second-direction C-band superfluorescence, the first direction being the direction of the erbium-doped fiber group to the broadband coupler, and the second direction being the erbium-doped fiber group to the wavelength division complex The direction of the device; the second direction C-band superfluorescence is reversed after passing through the wavelength division multiplexer, and the erbium-doped fiber in the erbium-doped fiber group is again excited to generate the first-direction L-band superfluorescence, and the broadband coupler is coupled with the first direction C. The band super-fluorescence and the first-direction L-band superfluorescence get C+L band superfluorescence, and the C+L band superfluorescence is transmitted outward through the branch isolator. In the superfluorescent fiber source provided by the present invention, the erbium-doped fiber group is composed of at least two parallel erbium-doped fibers, and the parallel structure of the erbium-doped fiber group is more convenient to adjust the length of the fiber to make the C+L band superfluorescence output. The characteristics of high flatness and wide spectral width, at the same time, the C+L-band super-fluorescent fiber light source provided by the invention can directly suppress the emission peak of the light source at 1530 nm and 1560 nm by adjusting the length of the optical fiber, and the super-fluorescence spectrum is high. The flat feature further increases the superfluorescence at 1530 nm and 1560 nm by the filter, so the super-fluorescent fiber source of the present invention has the characteristics of low cost, so the C+L band superfluorescence provided by the present invention The superfluorescence emitted by the fiber optic source has the characteristics of high flatness, wide spectral width, and low cost.

DRAWINGS

1 is a schematic structural view of a C+L-band super-fluorescent fiber light source according to a first embodiment of the present invention;

2 is a schematic structural view of a C+L-band super-fluorescent fiber light source according to a second embodiment of the present invention;

3 is a schematic structural view of a C+L-band super-fluorescent fiber light source according to a third embodiment of the present invention;

4 is a schematic structural view of a C+L-band super-fluorescent fiber light source according to a fourth embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be further described in detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

The invention provides a C+L-band super-fluorescent fiber light source, which can be applied to the fields of optical fiber communication, optical fiber sensing, optical imaging and optical device testing. Referring to FIG. 1 , a first embodiment of a C+L-band super-fluorescent fiber light source according to an embodiment of the present invention is shown. It should be understood that the method of “Nth embodiment” will be different. In the embodiment, the above "N" does not limit the number of embodiments of the present invention. The relationship between the various components and components in the first embodiment is detailed below:

The C+L-band super-fluorescent fiber source provided by the first embodiment of the present invention includes: a branch isolator, a broadband coupler, an erbium-doped fiber group, a wavelength division multiplexer, and a pump laser, a branch isolator and a broadband coupler. One end of the broadband coupler is connected to one end of the erbium-doped fiber group, and the other end of the erbium-doped fiber group is connected to the wavelength division multiplexer. The above erbium-doped fiber group is composed of at least two parallel erbium-doped fibers.

Before introducing the process of generating super-fluorescence of the light source of the present application, the transmission direction of the pump light is explained: the direction of the erbium-doped fiber group to the broadband coupler is determined as the first direction, and the erbium-doped fiber group is added to the wavelength division multiplexing. The direction of the device is set to the second direction. The following describes the process of generating super-fluorescence of the C+L-band super-fluorescent fiber source provided by the embodiment: the pump light from the pump laser is incident on the erbium-doped fiber group and the erbium-doped fiber is excited. The erbium-doped fiber in the group produces C-band superfluorescence in the first direction and C-band superfluorescence in the second direction. The C-band superfluorescence in the first direction will be transmitted to the broadband coupler, and the C-band superfluorescence in the second direction will be The wavelength division multiplexer transmits, reversely transmits after the wavelength division multiplexer, and re-excites the erbium-doped fiber in the erbium-doped fiber group to generate the L-band super-fluorescence transmitted in the first direction and the L-band transmitted in the second direction. Superfluorescence, it is to be understood that the L-band superfluorescence transmitted in the second direction will be reversely transmitted through the wavelength division multiplexer to become L-band superfluorescence transmitted in the first direction. Finally, the broadband coupler will transmit C-band super-fluorescence and L-band super-fluorescence to obtain C+L-band superfluorescence, and the coupled C+L-band superfluorescence will be transmitted outward through the branch isolator to form the light source. The output has a high flatness, wide bandwidth C+L band superfluorescence. It should be understood that the wideband coupler in this embodiment can split the transmitted pump light into two pump lights, and the wideband coupler can also couple the C-band and L-band super-fluorescence, that is, The wavelength range of the split coupling includes the pump wavelength and the C+L wavelength.

In a second embodiment, the pump laser is coupled to the first end of the branch isolator, see FIG. It should be understood that the branch isolator is a passive device that allows light to pass in one direction and prevents the passage in the opposite direction. The function is to limit the direction of the light so that the light can only be transmitted in one direction, and the light reflected by the optical fiber echoes. It can be well isolated by optical isolators to improve light wave transmission efficiency. In the present invention, the branch isolator has three ends, and the first end 1 of the branch isolator is connected to a pump laser through which the pump laser can input the pump light, which will pass through the branch isolator and broadband coupling. The device is incident on the erbium-doped fiber group to excite the erbium-doped fiber in the erbium-doped fiber group; the second end 2 of the branch isolator is connected to the broadband coupler and the incident pump light can be transmitted to the broadband coupler through the second end 2 At the same time, the C+L band superfluorescence transmitted from the first direction can also be transmitted to the branch isolator through the second end 2; the third end 3 of the branch isolator is the output end of the light source. The optical path in the C+L-band super-fluorescent fiber source provided by the embodiment is introduced here: the pump light from the pump laser is incident on the erbium-doped fiber group through the branch isolator and the broadband coupler, and the erbium-doped fiber group is excited. The erbium-doped fiber produces C-band superfluorescence in the first direction and C-band superfluorescence in the second direction. The C-band superfluorescence in the first direction will be transmitted to the broadband coupler, and the C-band superfluorescence in the second direction will be the wave. The multiplexer transmits, reversely transmits after the wavelength division multiplexer, and re-excites the erbium-doped fiber in the erbium-doped fiber group to generate the L-band super-fluorescence transmitted in the first direction and the L-band super-transmission in the second direction. Fluorescence, finally, the broadband coupler will transmit C-band superfluorescence and L-band superfluorescence to obtain C+L-band superfluorescence, and the C+L-band superfluorescence obtained by this coupling will pass through the third end of the branch isolator. External transmission, forming a high flatness, wide bandwidth C+L band superfluorescence output by the light source.

In a third embodiment, the pump laser is connected to the other end of the wavelength division multiplexer. Referring to FIG. 3, the pump light from the pump laser is incident on the erbium-doped fiber group via the wavelength division multiplexer, and the excitation is mixed. The erbium-doped fiber in the 铒 fiber group produces C-band superfluorescence in the first direction and C-band superfluorescence in the second direction. The C-band superfluorescence in the first direction will be transmitted to the broadband coupler, and the C-band in the second direction will be super. Fluorescence is transmitted to the wavelength division multiplexer, reversed by the wavelength division multiplexer, and the erbium-doped fiber in the erbium-doped fiber group is again excited to generate the L-band superfluorescence transmitted in the first direction and transmitted in the second direction. The L-band superfluorescence, finally, the broadband coupler will couple the C-band superfluorescence and the L-band superfluorescence to obtain the C+L-band superfluorescence, and the coupling of the C+L-band superfluorescence will pass through the branch isolator. The three ends are transmitted outward to form a high flatness, wide bandwidth C+L band superfluorescence output by the light source.

In a fourth embodiment, the pump laser is coupled to the splitting light, the first split end of the split coupler is coupled to the first end of the branch isolator, and the second split end of the split coupler and the other of the wavelength division multiplexer Connect at one end, see Figure 4. It should be understood that the split coupler is different from the wideband coupler described above, and is only a coupler that splits the pump wavelength. Like the connection relationship of the branch isolator port in the first embodiment, the second end thereof is connected to one end of the wideband coupler, and the resulting superfluorescence is transmitted outward through the third end 3. In a third embodiment, the pump light emitted by the pump laser is split into a first pump light and a second pump light by a splitting coupler, and the first pump light is emitted from the first light splitting end 1 and is branched and isolated. The device and the broadband coupler are incident on the erbium-doped fiber group; the second pump light is emitted from the second beam splitting end 2, and is incident on the erbium-doped fiber group via the wavelength division multiplexer. It should be understood that the first pump light and the second pump light power separated by the splitting coupler can be adjusted. The light path in the C+L-band super-fluorescent fiber source provided by the embodiment is introduced here: the pump light emitted by the pump laser is split by the splitting coupler to form the first pump light and the second pump light, the first pump Puguang is incident on the erbium-doped fiber group through the branch isolator and the broadband coupler, and the erbium-doped fiber in the erbium-doped fiber group is excited to generate the C-band superfluorescence in the first direction and the C-band superfluorescence in the second direction, the first direction. The C-band superfluorescence will be transmitted to the wideband coupler, and the second-direction C-band superfluorescence will be transmitted to the wavelength division multiplexer, reversed by the wavelength division multiplexer, and the excitation of the erbium-doped fiber group will be excited again. The 铒 fiber generates L-band superfluorescence transmitted in the first direction and L-band superfluorescence transmitted in the second direction; the second pump light is incident on the erbium-doped fiber group through the wavelength division multiplexer to excite the erbium-doped fiber group The erbium-doped fiber produces C-band superfluorescence in the first direction and C-band superfluorescence in the second direction. The C-band superfluorescence in the first direction will be transmitted to the broadband coupler, and the C-band superfluorescence in the second direction will be the WDM. Multiplexer transmission, reversed by wavelength division multiplexer The erbium-doped fiber in the erbium-doped fiber group is transmitted and re-excited to generate L-band superfluorescence transmitted in the first direction and L-band superfluorescence transmitted in the second direction. Finally, the wideband coupler will transmit C-band super-fluorescence and L-band super-fluorescence to obtain C+L-band superfluorescence. The C+L-band superfluorescence obtained by this coupling will be transmitted to the third end 3 of the branch isolator. Forming a high flatness, wide bandwidth C+L band superfluorescence output by the light source.

In still other examples of the above embodiments, the branch isolator, the wideband coupler, the erbium doped fiber set, the wavelength division multiplexer, and the pump laser are connected by fiber fusion coupling.

It is to be understood that by optimizing the pump power of the pump laser in the super-fluorescent fiber source provided by the present invention and the length of two erbium-doped fibers connected in parallel, the super-fluorescent fiber source can output a high-flatness, wide-bandwidth superfluorescence. At the same time, in the present invention, no filter is used, and the emission peak at 1530 nm and 1560 nm of the erbium-doped fiber can be suppressed directly by internal gain adjustment to make the spectrum high flat. At the same time, the present invention eliminates the necessity of using the conventional structure. The mirrors that are obtained make the structure simpler, which is beneficial to reducing the size of the light source and reducing the cost.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, and any person skilled in the art can disclose the patent according to the present invention within the scope disclosed by the present patent. The technical solutions and the inventive concepts thereof are equivalently replaced or changed, and are all within the scope of protection of the present invention.

Claims

A C+L-band super-fluorescent fiber source, characterized in that the super-fluorescent fiber source comprises: a branch isolator, a broadband coupler, an erbium-doped fiber group, a wavelength division multiplexer, and a pump laser; The fiber group is composed of at least two parallel erbium doped fibers;

The branch isolator is connected to one end of the broadband coupler, the other end of the broadband coupler is connected to one end of the erbium-doped fiber group, and the other end of the erbium-doped fiber group is multiplexed with the wavelength division Connection

The pump light emitted by the pump laser is incident on the erbium-doped fiber group, and the pump light excites the erbium-doped fiber group to generate a first direction C-band super-fluorescence and a second-direction C-band super-fluorescence, a first direction is a direction of the erbium-doped fiber group to the broadband coupler, the second direction is a direction of the erbium-doped fiber group to the wavelength division multiplexer; and the second direction is a C-band super Fluorescence is reversed through the wavelength division multiplexer, and the erbium-doped fiber in the erbium-doped fiber group is again excited to generate a first-direction L-band superfluorescence, and the broadband coupler couples the first-direction C-band superfluorescence And the first direction L-band superfluorescence obtains C+L band superfluorescence, and the C+L band superfluorescence is transmitted outward through the branch isolator.
A C+L-band superfluorescent fiber source as claimed in claim 1 wherein said pump laser is coupled to a first end of said branch isolator; said second end of said branch isolator and one end of said broadband coupler Connecting; the C+L band superfluorescence is transmitted outward through the third end of the branch isolator; pump light emitted by the pump laser is incident to the broadband via the branch isolator and the broadband coupler Erbium doped fiber group.
A C+L-band superfluorescent fiber source as claimed in claim 1, wherein said pump laser is connected to the other end of said wavelength division multiplexer, and said pump light from said pump laser is split by said wave A device is incident on the erbium doped fiber group.
The C+L-band super-fluorescent fiber source according to claim 1, wherein the pump laser is connected to a splitting coupler, and a first split end of the split coupler is connected to a first end of the branch isolator. a second split end of the split optical coupler is connected to the other end of the wavelength division multiplexer; a second end of the branch isolator is connected to one end of the wideband coupler; the C+L band superfluorescence passes The third end of the branch isolator is transmitted outward;

The pump light emitted by the pump laser is divided into a first pump light and a second pump light by the splitting coupler, and the first pump light is emitted from the first light splitting end, through the branch The isolator and the broadband coupler are incident on the erbium-doped fiber group; the second pump light is emitted from the second beam splitting end, and is incident on the erbium-doped fiber group through the wavelength division multiplexer.
The C+L-band superfluorescent fiber source according to any one of claims 1 to 4, wherein the branch isolator, the wideband coupler, the erbium-doped fiber group, the wavelength division multiplexer, and the pump laser They are connected by means of fiber fusion coupling.