Superfluorescent light source

Abstract

The utility model provides a kind of super fluorescent light source, including light source shell, drive control board, control interface, laser component and optical fiber component;Laser component includes tube core, fast axis collimating mirror, body bragg grating and focusing mirror;Optical fiber component includes optical fiber input end, gain optical fiber, melting point, input optical fiber, mode field adapter, output optical fiber and optical fiber output end;Control interface is arranged in the outer wall of light source shell;Drive control board, laser component, gain optical fiber, melting point, mode field adapter are arranged in the inside of light source shell, and output optical fiber extends to the outside of light source shell;Drive control board is connected with laser component, and is communicated with external device by control interface, accepts power supply;Laser component is connected with the optical fiber input end of optical fiber component.The utility model can overcome the defects, such as low coupling efficiency, power attenuation fast, complex structure in the prior art while maintaining wide spectrum, high power output, realize miniaturization, low-cost fiber-optic light source system.

Description

Technical Field

[0001] This utility model relates to the field of fiber optic light source technology, specifically to a superfluorescent light source. Background Technology

[0002] Existing fiber-optic superfluorescent light sources require coupling a single-mode semiconductor laser chip with a single-mode fiber to achieve single-mode fiber output, which results in low output power and difficult coupling. While superluminescent diodes (SLDs) can achieve broad-spectrum output, they suffer from low output power, rapid power decay, and susceptibility to local peaks in the spectrum. Supercontinuum lasers (SCLS) offer broad-spectrum, high-power output, but their complex structure, high manufacturing cost, and large size make them unsuitable for miniaturized, low-cost applications. For example, patent document CN111817118A discloses an integrated ASE light source product, including a pump laser core assembly, a pigtail assembly, and an active fiber assembly. The pump light is emitted from the pump laser core, coupled through a fiber lens into the pigtail assembly, and then enters the active fiber assembly. In the active fiber assembly, the pump light is converted into ASE signal light, which is then output from the output end of the active fiber assembly. For example, the existing patent document CN103199424A discloses an all-fiber superfluorescent light source, including a gain fiber and a pump source. The pump source pigtail is connected to the side of the gain fiber and enters the inner cladding of the gain fiber. After the core of the gain fiber absorbs the pump light, it generates superfluorescence, which is then output through one or both ends of the gain fiber. The junction coupling in these two existing patents is difficult, inconvenient to assemble, and not conducive to increasing the power of the light source and controlling costs.

[0003] Therefore, there is a need to develop a new type of superfluorescent light source with improved performance. Utility Model Content

[0004] The purpose of this invention is to provide a superfluorescent light source that can overcome the defects of existing technologies, such as low coupling efficiency, fast power attenuation, and complex structure, while maintaining a wide spectrum and high power output, thereby realizing a miniaturized and low-cost fiber optic light source system.

[0005] The technical solution of this utility model is as follows: This invention relates to a superfluorescent light source, comprising a light source housing, a drive control board, a control interface, a laser assembly, and an optical fiber assembly. The laser assembly includes a core, a fast-axis collimating lens, a volume Bragg grating, and a focusing lens arranged sequentially along the optical path propagation direction. The optical fiber assembly includes an optical fiber input end, a gain fiber, a melting point, an input fiber, a mode field adapter, an output fiber, and an optical fiber output end connected sequentially. The control interface is located on the outer wall of the light source housing. The drive control board, the laser assembly, and the gain fiber, melting point, and mode field adapter of the optical fiber assembly are located inside the light source housing. The output fiber extends to the outside of the light source housing and is connected to the external optical fiber output end. The drive control board is connected to the laser assembly and communicates with external devices and receives power supply through the control interface. The laser assembly is connected to the optical fiber input end of the optical fiber assembly. The pump light emitted from the core passes through the fast-axis collimating lens, the volume Bragg grating, and the focusing lens, and is coupled into the gain fiber through the end face of the optical fiber input end, where it generates multimode superfluorescence. The mode field adapter couples the multimode superfluorescence to the single-mode output fiber with low loss for transmission, and outputs it through the optical fiber output end.

[0006] Optionally, in the above-mentioned superfluorescent light source, the superfluorescent light source also includes a nozzle, which is disposed on the outer wall of the right side of the light source housing and the control interface is disposed on the outer wall of the left side of the light source housing. The output optical fiber extends through the nozzle to the outside of the light source housing.

[0007] Optionally, in the above-mentioned superfluorescent light source, the fiber input end, gain fiber, melting point, mode field adapter, and input fiber of the laser assembly and fiber assembly are disposed on the front side inside the light source housing; the drive control board is disposed on the back side inside the light source housing.

[0008] Optionally, in the above-mentioned superfluorescent light source, the drive control board adopts a dual-drive design of constant current drive from semiconductor laser and temperature control drive from thermoelectric cooler.

[0009] Optionally, in the above-mentioned superfluorescent light source, the gain fiber is a large-mode-field double-clad ytterbium-doped fiber.

[0010] Optionally, in the above-mentioned superfluorescent light source, the laser assembly also includes a housing, and the die, fast-axis collimating lens, volume Bragg grating and focusing lens are all disposed inside the housing.

[0011] Optionally, in the above-mentioned superfluorescent light source, the die is a semiconductor laser die with a wavelength of 976nm, and a thermoelectric cooler is provided below the die.

[0012] Optionally, in the above-mentioned superfluorescent light source, the control interface is a DB7W2 communication interface.

[0013] Optionally, in the above-mentioned superfluorescent light source, the input fiber is a double-clad fiber, the diameter of its core, cladding and coating layers being matched with the gain fiber; and the output fiber is a single-mode fiber.

[0014] Optionally, in the above-mentioned superfluorescent light source, the connector end face of the fiber output end is at an 8° angle.

[0015] The beneficial effects produced by the technical solution of this utility model are as follows: Compared with SLD, the superfluorescent light source based on semiconductor pumped gain fiber of this invention is easier to achieve a wider spectrum and higher output power; compared with supercontinuum light source, the superfluorescent light source of this invention has lower cost, simpler structure, and does not require ultrashort pulse pumping. Compared with other fiber-optic superfluorescent light sources, the superfluorescent light source of this invention uses a multimode semiconductor pump source directly coupled to the double-clad gain fiber. The pump light is transmitted in the inner cladding, with a larger diameter and higher coupling efficiency, which improves the utilization rate of the pump light. Using a multimode semiconductor laser for pumping, greater output power can be obtained.

[0016] This invention presents a superfluorescent light source based on semiconductor pumped gain fiber, which achieves miniaturization and low cost, and has characteristics such as wide spectrum and low coherence. It can be applied in fields such as high-precision sensing and medical imaging. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below.

[0018] Figure 1 This is a schematic diagram of the overall front structure of the superfluorescent light source of this utility model; Figure 1A This is a partial enlarged view of the laser component of the superfluorescent light source of this utility model; Figure 2 This is a partial structural diagram of the reverse side of the superfluorescent light source of this utility model; Figure 3 This is a schematic diagram of the side interface of the superfluorescent light source of this utility model.

[0019] Figure label: 1-Light source housing; 2-Nozzle; 3-Drive control board; 4-Control interface; 5-Laser assembly; 6-Fiber optic assembly; 7-Housing; 8-Core; 9-Thermoelectric cooler; 10-Fast axis collimating lens; 11-Voltage Bragg grating; 12-Focusing lens; 13-Gain fiber; 14-Fiber optic input end; 15-Melting point; 16-Mode field adapter; 17-Input fiber; 18-Output fiber; 19-Fiber optic output end. Detailed Implementation

[0020] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this invention. Rather, they are merely examples of systems consistent with some aspects of this invention as detailed in the appended claims.

[0021] The description of illustrative embodiments based on the principles of this invention is read in conjunction with the accompanying drawings, which are considered an integral part of the entire written description. Any references to directions or orientations in the description of the embodiments of this invention disclosed herein are merely for ease of description and are not intended to limit the scope of the invention in any way. Relative terms such as “downward,” “upward,” “horizontal,” “vertical,” “above,” “below,” “up,” “top,” “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the orientation as described or shown in the drawings discussed. These relative terms are for ease of description only and do not require the device to be constructed or operated in a particular orientation unless explicitly stated otherwise.

[0022] Terms such as “attachment,” “addition,” “connection,” “coupling,” and “interconnection” refer to relationships in which structures are directly or indirectly fixed or attached to each other through an intermediate structure, and where both are movable or rigidly attached or related unless otherwise expressly stated. Furthermore, the features and benefits of this invention are illustrated with reference to exemplary embodiments. Therefore, this invention is not expressly limited to such exemplary embodiments, which illustrate some possible non-limiting combinations of features that may exist alone or in combination with other features; the scope of this invention is defined by the appended claims.

[0023] This invention relates to a superfluorescent light source generated by pumping a gain fiber with a semiconductor laser. Using a semiconductor laser as the pump source, doped ions are excited to a high degree by exciting a doped fiber (such as ytterbium-doped fiber or erbium-doped fiber), achieving population inversion. In the absence of resonant cavity feedback, the excited-state particles generate photons through spontaneous emission. These photons are amplified by the gain medium, forming superfluorescence (amplified spontaneous emission). The superfluorescent light source exhibits characteristics such as a wide spectrum and low coherence. This invention's superfluorescent light source achieves miniaturization and low cost, possessing characteristics such as a wide spectrum and low coherence, and can be applied in fields such as high-precision sensing and medical imaging.

[0024] like Figure 1 and Figure 2 As shown, the superfluorescent light source of this utility model includes a light source housing 1, a nozzle 2, a drive control board 3, a control interface 4, a laser assembly 5, and an optical fiber assembly 6.

[0025] Laser assembly 5 includes a housing 7 and a die 8, a thermoelectric cooler (TEC) 9, and a fast-axis collimating lens 10 arranged sequentially along the optical path propagation direction (see...). Figure 1A The core 8, fast-axis collimating lens 10, volume Bragg grating 11, and focusing lens 12 are all housed within the casing 7.

[0026] The fiber optic assembly 6 includes a fiber optic input terminal 14, a gain fiber 13, a melting point 15, an input fiber 17, a mode field adapter 16, an output fiber 18, and a fiber optic output terminal 19, which are connected in sequence.

[0027] Both the nozzle 2 and the control interface 4 are located on the outer wall of the light source housing 1. Specifically, the control interface 4 is located on the left outer wall of the light source housing 1, and the nozzle 2 is located on the right outer wall of the light source housing 1. The drive control board 3, the laser assembly 5, and the fiber optic assembly 6 have their fiber optic input end 14, gain fiber 13, melting point 15, mode field adapter 16, and input fiber 17 located inside the light source housing 1. The output fiber 18 and the fiber optic output end 19 extend to the outside of the light source housing 1. Specifically, the output fiber 18 passes through the nozzle 2 on the right side of the light source housing 1 and extends to the outside of the light source housing 1, connecting with the external fiber optic output end 19. The fiber optic input end 14, gain fiber 13, melting point 15, mode field adapter 16, and input fiber 17 of the laser assembly 5 and the fiber optic assembly 6 are located on the front side inside the light source housing 1. Figure 1 The drive control board 3 is located on the reverse side inside the light source housing 1, such as... Figure 2 .

[0028] The drive control board 3 is connected to the laser assembly 5. Specifically, the drive module on the drive control board 3 supplies power to the die 8 in the laser assembly 5. The positive and negative terminals of the drive module output are connected to two pins of the housing 1 in the laser assembly 5, and these two pins are also connected to the positive and negative terminals of the die 8. The drive control board 3 adopts a dual-drive design, combining constant current drive for the semiconductor laser and temperature control drive for the TEC (thermoelectric cooler). The drive control board 3 communicates with external devices and receives power supply through the control interface 4 to enable the laser, adjust the laser current, configure the TEC temperature, and monitor the operating status.

[0029] Control interface 4 is a communication interface, such as Figure 3 Preferably, control interface 4 is a DB7W2 communication interface, but different interfaces can be used for control interface 4 depending on the actual application.

[0030] Laser assembly 5 is connected to the fiber input end 14 of fiber assembly 6. The chip 8 of laser assembly 5, which serves as the pump source, is a semiconductor laser chip, preferably a semiconductor laser chip with a wavelength of 976nm. Chip 8 is installed in housing 7, and a TEC cooler 9 for heat dissipation is provided below chip 8 to ensure laser power and wavelength stability. Along the optical propagation direction, a fast-axis collimating lens 10, a volume Bragg grating 11, and a focusing lens 12 are sequentially provided at the front end of chip 8. Among them, the fast-axis collimating lens 10 is used to compress the fast-axis divergence angle of the laser; the Bragg grating 11 is used to lock the output wavelength of the pump laser and compress the spectral linewidth, thereby improving the pump efficiency; the focusing lens 12 is used to focus the wavelength-locked pump light, which enters the gain fiber 13 through the fiber input end 14 of fiber assembly 6 to generate multimode superfluorescence.

[0031] Gain fiber 13 is a double-clad gain fiber, preferably a large-mode-field double-clad ytterbium-doped fiber. A multimode semiconductor pump source is directly end-coupled into the double-clad gain fiber. The pump light propagates within the inner cladding of gain fiber 13, resulting in a larger diameter and higher coupling efficiency, thus improving pump light utilization. Using a semiconductor laser as the pump source, the doped ions are excited to a higher state by exciting the doped fiber (such as ytterbium-doped fiber), achieving population inversion. In the absence of resonant cavity feedback, the excited-state particles generate photons through spontaneous emission. These photons are amplified by the gain medium, forming superfluorescence (amplified spontaneous emission).

[0032] Melting point 15 is the melting point of the gain fiber 13 and the input fiber 17 of the mode field adapter 16. At this melting point, the double-clad fiber is subjected to cladding light stripping to remove the unabsorbed residual pump light in the gain fiber 13. The characteristics of the residual pump light are contrary to the characteristics of superfluorescence. Removing the monochromatic pump laser can improve spectral purity, ensure the broadband and low-coherence characteristics of the superfluorescent light source, and avoid introducing noise and interference during application.

[0033] The mode field adapter 16 is used to match the mode fields of the gain fiber 13 and the single-mode fiber, enabling the multimode superfluorescence generated in the gain fiber to be coupled to the single-mode output fiber for transmission with low loss. The mode field adapter 16 can achieve efficient coupling between fibers with different mode field diameters, reducing coupling loss. This application can reduce reflection loss caused by mode mismatch during fusion splicing of large-mode-field double-clad fibers and single-mode fibers, and prevent lasing phenomena after a resonant cavity is formed between the fusion point and the fiber input end.

[0034] The input fiber 17 of the mode field adapter 16 is a large mode field double-clad fiber, whose core, cladding, and coating diameters are perfectly matched with those of the gain fiber 13 to reduce reflection and avoid the formation of a resonant cavity. The output fiber 18 is a single-mode fiber, serving as the output fiber for the light source.

[0035] Fiber optic input end 14 is a fiber optic connector used for the input end of gain fiber 13; fiber optic output end 19 is a fiber optic connector used for the output end of output fiber 18. Preferably, the end face of the connector at the fiber optic output end 19 is angled, more preferably at an 8° angle, such as a standard FC-APC connector. The condition for stable output of the superfluorescent light source without lasing is that the two ends of the fiber do not form a resonant cavity. If both the fiber input and output ends are planar, inherent Fresnel reflection will exist, easily forming a resonant cavity and thus inducing lasing. An angled output end reduces end-face reflection and avoids forming a resonant cavity with the fiber input end.

[0036] When the superfluorescent light source involved in this utility model is working, under the control of the drive control board 3, the multimode pump light emitted by the chip 8 passes through the fast axis collimating lens 10, the volume Bragg grating 11 and the focusing lens 12, and is coupled into the double-clad gain fiber 13 through the end face of the fiber input end 14, where multimode superfluorescence is generated. The mode field adapter 16 enables the multimode superfluorescence to be coupled to the single-mode output fiber 18 with low loss for transmission, and is output through the fiber output end 19.

[0037] The above-described embodiments are merely specific implementations of this utility model, used to illustrate the technical solutions of this utility model, and not to limit it. The protection scope of this utility model is not limited thereto. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this utility model. These modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A superfluorescent light source, characterized in that, Includes the light source housing, drive control board, control interface, laser assembly, and fiber optic assembly; The laser assembly includes a die, a fast-axis collimating lens, a volume Bragg grating, and a focusing lens arranged sequentially along the optical path propagation direction; The optical fiber assembly includes an optical fiber input terminal, a gain fiber, a melting point, an input fiber, a mode field adapter, an output fiber, and an optical fiber output terminal connected in sequence. The control interface is located on the outer wall of the light source housing; The drive control board, the laser assembly, and the gain fiber, melting point, and mode field adapter of the fiber optic assembly are disposed inside the light source housing. The output fiber extends to the outside of the light source housing and is connected to the external fiber output end. The drive control board is connected to the laser assembly and communicates with external devices and receives power supply through the control interface. The laser assembly is connected to the fiber input end of the fiber assembly. The pump light emitted from the core passes through the fast-axis collimating lens, the volume Bragg grating, and the focusing lens, and is coupled into the gain fiber through the end face of the fiber input end, where a multimode superfluorescence is generated. The mode field adapter enables the multimode superfluorescence to be coupled to the single-mode output fiber with low loss for transmission, and is output through the fiber output end.

2. The superfluorescent light source according to claim 1, characterized in that, The superfluorescent light source also includes a nozzle, which is disposed on the outer wall of the right side of the light source housing, and the control interface is disposed on the outer wall of the left side of the light source housing. The output optical fiber extends through the nozzle to the outside of the light source housing.

3. The superfluorescent light source according to claim 1, characterized in that, The laser assembly and the fiber optic assembly, including the fiber input end, gain fiber, melting point, mode field adapter, and input fiber, are disposed on the front side inside the light source housing; the drive control board is disposed on the back side inside the light source housing.

4. The superfluorescent light source according to claim 1, characterized in that, The drive control board adopts a dual-drive design, consisting of a semiconductor laser constant current drive and a thermoelectric cooler temperature control drive.

5. The superfluorescent light source according to claim 1, characterized in that, The gain fiber is a large-mode-field double-clad ytterbium-doped fiber.

6. The superfluorescent light source according to claim 1, characterized in that, The laser assembly also includes a housing, and the die, the fast-axis collimating lens, the volume Bragg grating, and the focusing lens are all disposed within the housing.

7. The superfluorescent light source according to claim 1, characterized in that, The die is a semiconductor laser die with a wavelength of 976nm, and a thermoelectric cooler is provided below the die.

8. The superfluorescent light source according to claim 1, characterized in that, The control interface is a DB7W2 communication interface.

9. The superfluorescent light source according to claim 1, characterized in that, The input fiber is a double-clad fiber, and the diameters of its core, cladding, and coating are matched with those of the gain fiber; and the output fiber is a single-mode fiber.

10. The superfluorescent light source according to claim 1, characterized in that, The connector end face of the fiber optic output end is at an 8° angle.

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