Passive laser lighting system of long-distance optical fiber lamp

Abstract

The invention discloses a passive laser lighting system of a long-distance optical fiber lamp, and relates to the field of laser lighting. In order to solve the defects of poor practicability, high equipment cost, low conversion efficiency and high long-distance loss of the existing long-distance laser illumination, a laser is used for emitting infrared laser, and a multimode long-distance optical fiber is used for transmitting the infrared laser; the up-conversion device is used for up-converting the infrared laser into blue light or ultraviolet light through frequency doubling and then outputting the blue light or the ultraviolet light; and the white light lamp is used for converting the blue light or the ultraviolet light into white light. The invention is mainly used for long-distance laser illumination.

Description

Technical Field

[0001] The present invention relates to the field of laser lighting, and in particular to a passive laser lighting system for a long-distance fiber optic lamp. Background Art

[0002] Existing white light generating devices generally directly convert blue light into white light, and the fiber optic transmission is blue light. This solution will have high transmission loss due to long distance during long-distance transmission; there are also white light generating devices that split 980nm laser light and directly convert it into RGB white light through upconversion fluorescent materials, but the direct conversion has low upconversion efficiency and is difficult to meet the lighting requirements; and it can only convert 980nm laser light; there are also white light generating devices that generate white light through spectral broadening materials. First, the cost of spectral broadening materials is high, and second, the conversion efficiency of this kind is low.

[0003] Although the glass optical fiber for laser transmission has the advantages of good insulation, strong heat resistance, good corrosion resistance, and high mechanical strength, its disadvantages are brittleness and poor wear resistance. Moreover, the transmitted laser has a high energy density, and once it breaks and is exposed, it is easy to form a dangerous point.

[0004] Therefore, there is a need for a passive laser lighting system for a long-distance fiber optic lamp that can improve the practicability of long-distance laser lighting, has low cost, high conversion efficiency, and less long-distance loss. Summary of the Invention

[0005] In order to solve the defects of poor practicability, high equipment cost, low conversion efficiency, and high long-distance loss of existing long-distance laser lighting, the present invention provides a passive laser lighting system for a long-distance fiber optic lamp that can improve the practicability of long-distance laser lighting, has low cost, high conversion efficiency, and less long-distance loss.

[0006] A passive laser lighting system for a long-distance fiber optic lamp according to the present invention includes a laser, a multimode long-distance optical fiber, an upconversion device, and a white light lamp. The laser is used to emit infrared laser light, the multimode long-distance optical fiber is used to transmit the infrared laser light, the upconversion device is used to frequency-double and upconvert the infrared laser light into blue light or ultraviolet light and then output it, and the white light lamp is used to convert the blue light or ultraviolet light into white light.

[0007] The beneficial effects of adopting the above technical solution are:

[0008] The long-distance laser illumination system described in the present invention uses an infrared laser with a wavelength of 915 nm as a laser pump, and passive devices are used to generate blue light through intracavity frequency doubling, and then white light is generated through a phosphor. The fundamental frequency light (such as 980 nm or 980 nm) is frequency doubled through a nonlinear crystal (such as LBO, BBO or PPLN) to generate blue light with a wavelength of 490 nm. By frequency doubling the 490-nm blue light again through a nonlinear crystal, ultraviolet light with a wavelength of 235 nm is generated. Through the combination of pumping, gain and frequency doubling technologies, the laser system can efficiently generate blue light or ultraviolet light, which is widely used in the fields of industry, medicine and scientific research.

[0009] Further: The input of the laser is pump light or fundamental frequency light; when the infrared laser is pump light, the upconversion device is a laser resonator; when the infrared laser is fundamental frequency light, the upconversion device is an external cavity frequency doubling device.

[0010] The beneficial effects of adopting the above technical solutions are:

[0011] The upconversion device uses a laser resonator to perform upconversion on the pump light, which can significantly improve the efficiency and performance of the upconversion process, improve the upconversion efficiency, enhance the light field intensity, and reduce the pump threshold. The external cavity frequency doubling device usually uses high-quality nonlinear crystals and can efficiently convert the fundamental frequency light into upconversion light through precise phase matching design.

[0012] Further: The laser resonator includes a mirror, a laser gain crystal, a frequency doubling crystal and a half mirror, and the mirror, the laser gain crystal, the frequency doubling crystal and the half mirror are arranged in sequence.

[0013] The total reflection mirror is used to maintain optical feedback, and the output coupling mirror partially transmits the laser; the laser gain crystal serves as a gain medium to amplify the optical signal through stimulated emission; the frequency doubling crystal converts the fundamental frequency light into frequency doubled light through nonlinear optical effects; the half mirror is used to partially reflect the light to maintain oscillation and partially transmit the light to output the laser.

[0014] Further: The wavelength of the fundamental frequency light is 880 nm - 980 nm.

[0015] Further: When the upconversion device is a laser resonator, the wavelength of the input pump light is 808 nm, 880 nm or 915 nm.

[0016] Further: The laser resonator is a solid-state laser cavity, and a frequency doubling crystal is arranged in the solid-state laser cavity. The frequency doubling crystal is used to double or triple the excited infrared laser, and finally generate blue light or ultraviolet light.

[0017] Further: The frequency doubling crystal is an LBO crystal, a KTP crystal or a PPLN crystal.

[0018] Further: when the up-conversion device is an external cavity frequency doubling device, the up-conversion device is a second harmonic generation crystal of 915 nm, 940 nm or 980 nm.

[0019] Further: it further includes an explosion-proof cabinet, the laser is placed in the explosion-proof cabinet, and the multimode long-distance optical fiber is an armored optical fiber.

[0020] Further: a sleeve is arranged outside the multimode long-distance optical fiber, and the material of the sleeve is galvanized steel pipe.

[0021] The beneficial effects of the present invention are as follows:

[0022] The present invention transmits infrared laser to a lamp at a long distance through an optical fiber, and then up-converts and frequency-doubles the infrared laser to visible light; in the process of transmitting light through the optical fiber, high-power infrared laser is transmitted to the lamp, so as to frequency-double or up-convert the infrared laser to obtain visible light blue light and purple light, and change the white light through fluorescence to realize laser lighting. The present invention greatly improves the practicability of laser lighting at a long distance and can be widely applied to the lighting fields of mines, oil depots, and dangerous goods warehouses. Description of the Drawings

[0023] Figure 1 is a passive laser lighting device for a long-distance fiber lamp;

[0024] Figure 2 is a schematic diagram of a laser resonator device;

[0025] Figure 3 is a schematic diagram of a laser frequency doubling device. Detailed Embodiments

[0026] The following are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. The following embodiments are only used to explain the present invention and cannot be construed as a limitation of the present invention. The protection scope of the present invention should be subject to the protection scope of the claims. The embodiments of the present invention are described in detail below. For the convenience of describing the present invention and simplifying the description, the technical terms used in the specification of the present invention should be interpreted in a broad sense, including but not limited to the conventional substitution schemes not mentioned in the present application, and including both direct implementation methods and indirect implementation methods.

[0027] Embodiment 1

[0028] Combined with Figures 1 - 3For this embodiment, a passive laser illumination system for a long-distance fiber optic lamp disclosed in this embodiment includes a laser, a multimode long-distance fiber, a frequency up-conversion device, and a white light lamp. The laser is used to emit infrared laser light, the multimode long-distance fiber is used to transmit the infrared laser light, the frequency up-conversion device is used to frequency double and up-convert the infrared laser light into blue light or ultraviolet light and then output it, and the white light lamp is used to convert the blue light or ultraviolet light into white light.

[0029] As Figure 1 shown, the passive laser illumination device for the long-distance fiber optic lamp is divided into three parts. The first part is the laser and the coupled long-distance multimode fiber, the second part is the frequency up-conversion fiber device, and the third part is the white light lamp. The infrared laser light emitted by the laser passes through the long-distance multimode fiber, and the infrared light of the laser passes through the frequency up-conversion device, is frequency double and up-converted into blue light or ultraviolet light and then output. The blue light or ultraviolet light then passes through the fluorescent sheet in the white light lamp and becomes white light for illumination. The basic principle is that the output of the laser is pump laser light or fundamental frequency light. The pump laser light becomes blue light or ultraviolet light in the frequency up-conversion device, and the blue light or ultraviolet light becomes white light through the white light phosphor at the white light lamp. In the described long-distance laser illumination system, an infrared laser with a wavelength of 915 nm is used as the laser pump, and a passive device is made to generate blue light by intracavity frequency doubling, and then white light is generated through the phosphor. The fundamental frequency light (such as 980 nm or 980 nm) is frequency doubled through a nonlinear crystal (such as LBO, BBO, or PPLN) to generate blue light of 490 nm. By frequency doubling the 490-nm blue light again through a nonlinear crystal, ultraviolet light of 235 nm is generated. Through the combination of pumping, gain, and frequency doubling technologies, the laser system can efficiently generate blue light or ultraviolet light, which is widely used in industrial, medical, and scientific research fields.

[0030] The input of the laser is pump light or fundamental frequency light; when the infrared laser light is pump light, the frequency up-conversion device is a laser resonator cavity; when the infrared laser light is fundamental frequency light, the frequency up-conversion device is an external cavity frequency doubling device. The input of the laser is pump light or fundamental frequency light. If it is pump light, the frequency up-conversion device is a blue light or ultraviolet light laser resonator cavity. If it is fundamental frequency light, the frequency up-conversion device is an external cavity frequency doubling device, and the output light is blue light, and the fundamental frequency light is 880 nm - 980 nm. The frequency up-conversion device uses a laser resonator cavity to perform up-conversion on the pump light, which can significantly improve the efficiency and performance of the up-conversion process, can improve the up-conversion efficiency, enhance the light field intensity, and reduce the pump threshold. The external cavity frequency doubling device usually uses a high-quality nonlinear crystal and, through precise phase matching design, can efficiently convert the fundamental frequency light into up-conversion light.

[0031] As Figure 2As shown, the laser resonator includes a mirror, a laser gain crystal, a frequency doubling crystal, and a semi-transparent mirror, which are arranged in sequence. The total reflection mirror is used to maintain optical feedback, and the output coupling mirror partially transmits the laser; the laser gain crystal serves as a gain medium to amplify the optical signal through stimulated emission; the frequency doubling crystal converts the fundamental frequency light into frequency doubled light through nonlinear optical effects; the semi-transparent mirror is used to partially reflect light to maintain oscillation and partially transmit light to output the laser. The wavelength of the fundamental frequency light is 880 nm - 980 nm. The gain crystal can also be a gain fiber.

[0032] When the upconversion device is a laser resonator, the wavelength of the input pump light is 808 nm, 880 nm, or 915 nm. The laser resonator is a solid-state laser cavity, and a frequency doubling crystal is arranged in the solid-state laser cavity. The frequency doubling crystal is used to double or triple the excited infrared laser to finally generate blue light or ultraviolet light. The frequency doubling crystal is an LBO crystal, a KTP crystal, or a PPLN crystal. When the upconversion device is an external cavity frequency doubling device, the upconversion device is a frequency doubling crystal of 915 nm, 940 nm, or 980 nm.

[0033] When the upconversion device is a laser resonator, the input laser is a pump laser of 808 nm, 880 nm, or 915 nm. The laser resonator can be a solid-state laser cavity, and the frequency doubling crystal is placed in the resonator cavity to double or triple the excited laser to finally generate blue light or ultraviolet light. The frequency doubling crystal is an LBO crystal, a KTP crystal, or a PPLN crystal. When the upconversion device is an external cavity frequency doubling device, the upconversion device is a frequency doubling crystal of 915 nm, 940 nm, or 980 nm. The white light lamp mainly converts blue light or ultraviolet light into white light through phosphors to achieve white light illumination.

[0034] The passive laser lighting system of the long-distance fiber optic lamp further includes an explosion-proof cabinet. The laser is placed in the explosion-proof cabinet, and the multimode long-distance fiber is an armored fiber. Since the laser emitted by the laser has concentrated energy, if it needs to be used underground, explosion-proof isolation is required and it can be placed in the explosion-proof cabinet for flameproofing.

[0035] A sleeve is arranged outside the multimode long-distance fiber, and the material of the sleeve is galvanized steel pipe. By selecting armored fiber or laying the fiber in a galvanized steel pipe for enhanced protection, and adding real-time monitoring of fiber breakage and fault point location by an optical time domain reflectometer (OTDR), the interruption of the fiber will result in the interruption of light.

[0036] Through the airtight design of optical devices, it is ensured that all the unplugable ports on site emit scattered laser light after beam expansion, reducing the harm of concentrated energy to the human eye and the environment.

[0037] When repairing and replacing the laser illumination lamp of the terminal, sometimes it is impossible to turn off the entire lighting system. In this case, a anti-burning reflective protection cap can be screwed onto the connection port of the optical fiber and the lamp to prevent the harm caused by light leakage.

Claims

1. A passive laser lighting system for long-distance fiber optic lamps, characterized in that: The invention comprises a laser, a multimode long-distance optical fiber, an up-conversion device and a white light lamp. The laser is used to emit infrared laser, the multimode long-distance optical fiber is used to transmit infrared laser, the up-conversion device is used to frequency-double the infrared laser and up-convert it into blue light or ultraviolet light for output, and the white light lamp is used to convert blue light or ultraviolet light into white light.

2. The passive laser lighting system for a long-distance fiber optic lamp according to claim 1, characterized in that: The input of the laser is pump light or fundamental frequency light; when the infrared laser is pump light, the up-conversion device is a laser resonant cavity; when the infrared laser is fundamental frequency light, the up-conversion device is an external cavity frequency doubling device.

3. The passive laser lighting system for a long-distance fiber optic lamp according to claim 2, characterized in that: The laser resonant cavity comprises a reflecting mirror, a laser gain crystal, a frequency doubling crystal and a half mirror, and the reflecting mirror, the laser gain crystal, the frequency doubling crystal and the half mirror are arranged in sequence.

4. The passive laser lighting system for a long-distance fiber optic lamp according to claim 2, characterized in that: The wavelength of the fundamental frequency light is 880nm-980nm.

5. The passive laser lighting system for a long-distance fiber optic lamp according to claim 2, characterized in that: When the up-conversion device is a laser resonant cavity, the wavelength of the input pump light is 808 nm, 880 nm or 915 nm.

6. The passive laser lighting system for a long-distance fiber optic lamp according to claim 2, characterized in that: The laser resonant cavity is a solid laser cavity, and a frequency doubling crystal is arranged in the solid laser cavity. The frequency doubling crystal is used to double or triple the excited infrared laser to finally generate blue light or ultraviolet light.

7. The passive laser lighting system for a long-distance fiber optic lamp according to claim 6, characterized in that: The frequency doubling crystal is an LBO crystal, a KTP crystal or a PPLN crystal.

8. The passive laser lighting system for a long-distance fiber optic lamp according to claim 6, characterized in that: When the up-conversion device is an external cavity frequency doubling device, the up-conversion device is a doubled frequency crystal of 915nm, 940nm or 980nm.

9. The passive laser lighting system for a long-distance fiber optic lamp according to claim 1, characterized in that: It also includes an explosion-proof cabinet, the laser is placed in the explosion-proof cabinet, and the multi-mode long-distance optical fiber is an armored optical fiber.

10. The passive laser lighting system of a long-distance fiber optic lamp according to claim 1, characterized in that: A sleeve is arranged outside the multi-mode long-distance optical fiber, and the material of the sleeve is a galvanized steel pipe. Compared with traditional electric-driven lighting technology, the laser fiber optic lighting system completely realizes optoelectronic separation between the transmission and application ends, which makes a qualitative leap in safety.

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