CN105846308A - Spectrum synthesis device and method based on 45-degree incident dichroscope - Google Patents

Abstract

The invention discloses a spectrum synthesis device and method based on a 45° incidence of a dichroic mirror. Four fiber lasers emit laser light at the same time, wherein the laser light emitted by the first fiber laser is reflected by the first cut-off filter, and the second fiber laser emits laser light. The emitted laser light is transmitted through the first cut-off filter, the transmitted light and the reflected light are combined into one beam and injected into the second cut-off filter, reflected by the second cut-off filter, and the laser emitted by the third laser fiber laser passes through the second cut-off filter. Filter transmission, the transmitted light and the emitted light are combined into one beam, which enters the third cut-off filter and is reflected by the third cut-off filter, while the laser light emitted by the fourth fiber laser is transmitted through the third cut-off filter , the transmitted light and reflected light are combined into one beam and emitted. The present invention obtains a laser output of more than 20kW by combining four 6kW fiber lasers. Since the working angle of the cut-off filter is 45°, the overall device has a simple and compact structure, high beam combining efficiency, and good beam quality and stability. .

Description

Spectrum synthesis device and method based on 45° incidence of dichroic mirror

technical field

The invention relates to the field of strong laser beam combining, in particular to a spectrum combining device and method based on a 45° incident dichroic mirror.

Background technique

Chinese patent CN201310579762.7 proposes a "spectral beam combining 10,000-watt fiber laser based on volume Bragg grating", which effectively combines five fiber laser beams by using a volume Bragg grating to achieve beam-combining 10,000-watt laser power output.

Chinese patent CN201510181571.4 also proposes "A Multi-Wavelength Beam Combining System and Method". Through the mutual cooperation of laser arrays, lens groups, and dispersive elements, the beam combining of multiple laser beams with different wavelengths is realized, but they use The beamcombining elements are all gratings, which have a lower power threshold and are more sensitive to positional tolerances than cut-off filters. At the same time, as the incident laser power increases, the laser spectrum will gradually broaden, which will lead to the deterioration of the combined beam quality.

Contents of the invention

The object of the present invention is to provide a spectral synthesis device and method based on dichroic mirror 45° incidence, which is not sensitive to position tolerance, the system is stable, and the power threshold is high, which can reach a power output of 24kW. The steepness of the spectral curve is high, so that the broadening of the laser spectrum has little effect on the quality of the combined beam.

The technical solution to realize the object of the present invention is: a kind of spectrum synthesis device based on dichroic mirror 45° incidence, including the first fiber laser, the second fiber laser, the third laser fiber laser, the fourth fiber laser, the first cut-off filter, the second cut-off filter and the third cut-off filter, the lasers emitted by the first fiber laser and the third fiber laser are parallel, the lasers emitted by the second fiber laser and the fourth fiber laser are parallel, and the second The lasers emitted by the fiber laser and the fourth fiber laser are perpendicular to the lasers emitted by the first fiber laser and the third fiber laser respectively; the first cut-off filter is located at the intersection of the first fiber laser and the second fiber laser. The second cutoff filter is located at the intersection of the second fiber laser and the third fiber laser emitting laser light, and the third cutoff filter is located at the junction of the third fiber laser and the fourth fiber laser emission.

The first fiber laser, the second fiber laser, the third fiber laser, and the fourth fiber laser simultaneously emit laser light, wherein the laser light emitted by the first fiber laser is reflected by the first cut-off filter, and the laser light emitted by the second fiber laser passes through the second fiber laser. The first cut-off filter transmits, the transmitted light and the reflected light are combined into one beam and enter the second cut-off filter, reflected by the second cut-off filter, and the laser emitted by the third laser fiber laser is transmitted through the second cut-off filter. The transmitted light and emitted light are combined into one beam, injected into the third cut-off filter, reflected by the third cut-off filter, while the laser light emitted by the fourth fiber laser is transmitted through the third cut-off filter, and the transmitted light Combining the reflected light and the reflected light into one beam, that is, combining the four beams of laser light.

A method for spectral synthesis using a spectral synthesis device based on a dichroic mirror 45 ° of incidence, the method is as follows:

The first fiber laser, the second fiber laser, the third fiber laser, and the fourth fiber laser simultaneously emit laser light, wherein the laser light emitted by the first fiber laser is reflected by the first cut-off filter, and the laser light emitted by the second fiber laser passes through the second fiber laser. The first cut-off filter transmits, the transmitted light and the reflected light are combined into one beam and enter the second cut-off filter, reflected by the second cut-off filter, and the laser emitted by the third laser fiber laser is transmitted through the second cut-off filter. The transmitted light and emitted light are combined into one beam, injected into the third cut-off filter, reflected by the third cut-off filter, while the laser light emitted by the fourth fiber laser is transmitted through the third cut-off filter, and the transmitted light Combining the reflected light and the reflected light into one beam, that is, combining the four beams of laser light.

Compared with the prior art, the present invention has the remarkable advantages that: by combining four 6kW fiber lasers, a laser output exceeding 20kW is obtained, and the structure of the overall device is simple and compact because the working angle of the cut-off filter is 45° , High beam combining efficiency, good beam quality and stability.

Description of drawings

Fig. 1 is the structural schematic diagram of the spectral synthesis device based on the dichroic mirror 45 ° of incidence of the present invention

detailed description

The present invention will be described in further detail below in conjunction with the accompanying drawings.

In conjunction with Figure 1, a spectral synthesis device based on a dichroic mirror at 45° incidence, including a first fiber laser 1, a second fiber laser 2, a third fiber laser 3, a fourth fiber laser 4, a first cut-off filter sheet 5, the second cut-off filter 6 and the third cut-off filter 7, the lasers emitted by the first fiber laser 1 and the third fiber laser 3 are parallel, the lasers emitted by the second fiber laser 2 and the fourth fiber laser 4 parallel, and the laser light emitted by the second fiber laser 2 and the fourth fiber laser 4 is perpendicular to the laser light emitted by the first fiber laser 1 and the third fiber laser 3 respectively; the first cut-off filter 5 is located between the first fiber laser 1 and the The junction where the second fiber laser 2 emits laser light, the second cut-off filter 6 is located at the junction where the second fiber laser 2 and the third fiber laser 3 emit laser light, and the third cut-off filter 7 is located at the third fiber laser 3 and the fourth fiber laser 4 emit laser light at the junction.

The first fiber laser 1, the second fiber laser 2, the third fiber laser 3, and the fourth fiber laser 4 simultaneously emit laser light, wherein the laser light emitted by the first fiber laser 1 is reflected by the first cut-off filter 5, and the second fiber laser The laser light emitted by the laser 2 is transmitted through the first cut-off filter 5, the transmitted light and the reflected light are combined into a beam and injected into the second cut-off filter 6, reflected by the second cut-off filter 6, and the third laser fiber laser 3 emits The laser light is transmitted through the second cut-off filter 6, the transmitted light and the emitted light are combined into one beam, injected into the third cut-off filter 7, reflected by the third cut-off filter 7, and the fourth fiber laser 4 emits The laser light is transmitted through the third cut-off filter 7, and the transmitted light and reflected light are combined into one beam and emitted, that is, the four laser beams are combined.

The included angle between the first cut-off filter 5 and the laser emitted by the first fiber laser 1 is 45°; the included angle between the second cut-off filter 6 and the laser emitted by the third fiber laser 3 is 45°; the included angle between the third cut-off filter 7 and the laser light emitted by the third laser fiber laser 3 is 45°.

The first fiber laser 1, the second fiber laser 2, the third fiber laser 3 and the fourth fiber laser 4 are all ytterbium-doped fiber lasers, the central wavelength λ is between 1.06-1.1 μm, and the 20dB linewidth is less than 23nm , Laser beam collimated output, continuous output 6kW average power.

The center wavelengths λ ₁ , λ ₂ , λ ₃ , and λ ₄ of the four fiber lasers are equally spaced, and the wavelength spacing is greater than 7nm.

The diameter of the first cut-off filter 5 is 50 mm, and the width is 10 mm. The first cut-off filter 5 is highly reflective to the laser light emitted by the first fiber laser 1, and the reflectivity is greater than 99.9%. The laser is highly transparent, the transmittance is greater than 98%, and the bandwidth from 0.1% to 98% of the transmittance is less than 9nm.

The diameter of the second cut-off filter 6 is 50 mm, and the width is 10 mm. The second cut-off filter 6 is highly reflective to the laser light emitted by the first fiber laser 1 and the laser light emitted by the second fiber laser 2, and the reflectivity is greater than 99.9%. , the laser light emitted by the third laser fiber laser 3 is highly transparent, the transmittance is greater than 98%, and the bandwidth from 0.1% to 98% of the transmittance is less than 9nm.

The third cut-off filter 7 has a diameter of 50 mm and a width of 10 mm. The third cut-off filter 7 is highly reflective to the laser light emitted by the first fiber laser 1, the second fiber laser 2 and the third laser fiber laser 3. The transmission rate is greater than 99.9%, and the laser light emitted by the fourth fiber laser 4 is highly transparent, the transmittance is greater than 98%, and the bandwidth from 0.1% to 98% of the transmittance is less than 9nm.

The power thresholds of the first cut-off filter 5 , the second cut-off filter 6 and the third cut-off filter 7 are all greater than 24kW.

A method for spectral synthesis using a spectral synthesis device based on a dichroic mirror 45 ° of incidence, the method is as follows:

The first fiber laser 1, the second fiber laser 2, the third fiber laser 3, and the fourth fiber laser 4 simultaneously emit laser light, wherein the laser light emitted by the first fiber laser 1 is reflected by the first cut-off filter 5, and the second fiber laser The laser light emitted by the laser 2 is transmitted through the first cut-off filter 5, the transmitted light and the reflected light are combined into a beam and injected into the second cut-off filter 6, reflected by the second cut-off filter 6, and the third laser fiber laser 3 emits The laser light is transmitted through the second cut-off filter 6, the transmitted light and the emitted light are combined into one beam, injected into the third cut-off filter 7, reflected by the third cut-off filter 7, and the fourth fiber laser 4 emits The laser light is transmitted through the third cut-off filter 7, and the transmitted light and reflected light are combined into one beam and emitted, that is, the four laser beams are combined.

The included angle between the first cut-off filter 5 and the laser emitted by the first fiber laser 1 is 45°; the included angle between the second cut-off filter 6 and the laser emitted by the third fiber laser 3 is 45°; the included angle between the third cut-off filter 7 and the laser light emitted by the third laser fiber laser 3 is 45°.

In summary, the present invention obtains a laser output exceeding 20kW by combining four 6kW fiber lasers. Since the working angle of the cut-off filter is 45°, the structure of the overall device is simple and compact, and the efficiency of combining beams is high. Good quality and stability.

Claims (10)

1. A spectral synthesis device based on a 45° incident dichroic mirror, characterized in that it includes a first fiber laser (1), a second fiber laser (2), a third fiber laser (3), and a fourth optical fiber Laser (4), first cut-off filter (5), second cut-off filter (6) and third cut-off filter (7), first fiber laser (1) and third fiber laser (3 ), the lasers emitted by the second fiber laser (2) and the fourth fiber laser (4) are parallel, and the lasers emitted by the second fiber laser (2) and the fourth fiber laser (4) are respectively parallel to the first fiber The lasers emitted by the laser (1) and the third fiber laser (3) are vertical; the first cut-off filter (5) is located at the junction of the lasers emitted by the first fiber laser (1) and the second fiber laser (2). The second cut-off filter (6) is located at the intersection of the second fiber laser (2) and the third fiber laser (3) emitting laser light, and the third cut-off filter (7) is located at the junction of the third fiber laser (3) and the third fiber laser (3) The junction where the fourth fiber laser (4) emits laser light; The first fiber laser (1), the second fiber laser (2), the third fiber laser (3), and the fourth fiber laser (4) simultaneously emit laser light, wherein the laser emitted by the first fiber laser (1) passes through the first Reflected by the cut-off filter (5), the laser light emitted by the second fiber laser (2) is transmitted through the first cut-off filter (5), and the transmitted light and reflected light are combined into one beam and enter the second cut-off filter (6) , reflected by the second cut-off filter (6), the laser light emitted by the third laser fiber laser (3) is transmitted through the second cut-off filter (6), the transmitted light and the emitted light are combined into one beam, and enter the first Three cut-off filters (7), reflected by the third cut-off filter (7), while the laser light emitted by the fourth fiber laser (4) is transmitted through the third cut-off filter (7), the transmitted light and reflection The photosynthesis is a beam of output, that is, the four beams of laser beams are combined. 2. The spectrum synthesis device based on dichroic mirror 45° incidence according to claim 1, characterized in that: the laser light emitted by the first cut-off filter (5) and the first fiber laser (1) presents The included angle between the second cut-off filter (6) and the laser emitted by the third laser fiber laser (3) is 45°; the third cut-off filter (7) and the third laser The included angle of the laser light emitted by the fiber laser (3) is 45°. 3. The spectrum synthesis device based on 45° incident dichroic mirror according to claim 1, characterized in that: the first fiber laser (1), the second fiber laser (2), the third fiber laser ( 3) and the fourth fiber laser (4) are both ytterbium-doped fiber lasers, the central wavelength λ is between 1.06-1.1μm, the 20dB line width is less than 23nm, the laser beam is collimated and output, and can continuously output 6kW average power. 4. the spectral synthesis device based on dichroic mirror 45 ° of incidence according to claim 3, is characterized in that: the central wavelength λ ₁ of four fiber lasers, λ ₂ , λ ₃ , λ ₄ are equally spaced, and the wavelength spacing is greater than 7nm. 5. The spectrum synthesis device based on dichroic mirror 45° incidence according to claim 1, characterized in that: the first cut-off filter (5) has a diameter of 50mm and a width of 10mm, and the first cut-off filter The sheet (5) is highly reflective to the laser light emitted by the first fiber laser (1), with a reflectivity greater than 99.9%, and highly transparent to the laser light emitted by the second fiber laser (2), with a transmittance greater than 98%, and a transmittance ranging from 0.1% to 98% of the bandwidth is less than 9nm. 6. The spectrum synthesis device based on dichroic mirror 45° incidence according to claim 1, characterized in that: the second cut-off filter (6) has a diameter of 50mm and a width of 10mm, and the second cut-off filter The sheet (6) is highly reflective to the laser light emitted by the first fiber laser (1) and the laser light emitted by the second fiber laser (2), with a reflectivity greater than 99.9%, and highly transparent to the laser light emitted by the third fiber laser (3). The transmittance is greater than 98%, and the bandwidth from 0.1% to 98% of the transmittance is less than 9nm. 7. The spectrum synthesis device based on dichroic mirror 45° incidence according to claim 1, characterized in that: the third cut-off filter (7) has a diameter of 50mm and a width of 10mm, and the third cut-off filter The sheet (7) is highly reflective to the laser light emitted by the first fiber laser (1), the second fiber laser (2) and the third fiber laser (3), the reflectivity is greater than 99.9%, and the laser emitted by the fourth fiber laser (4) The laser is highly transparent, the transmittance is greater than 98%, and the bandwidth from 0.1% to 98% of the transmittance is less than 9nm. 8. The spectral synthesis device based on dichroic mirror 45° incidence according to claim 1, characterized in that: the first cut-off filter (5), the second cut-off filter (6) and the third cut-off filter The power thresholds of the cut-off filters (7) are all greater than 24kW. 9. A spectral synthesis method using a spectral synthesis device based on dichroic mirror 45 ° of incidence as claimed in claim 1, is characterized in that, the method is as follows: The first fiber laser (1), the second fiber laser (2), the third fiber laser (3), and the fourth fiber laser (4) simultaneously emit laser light, wherein the laser emitted by the first fiber laser (1) passes through the first Reflected by the cut-off filter (5), the laser light emitted by the second fiber laser (2) is transmitted through the first cut-off filter (5), and the transmitted light and reflected light are combined into one beam and enter the second cut-off filter (6) , reflected by the second cut-off filter (6), the laser light emitted by the third laser fiber laser (3) is transmitted through the second cut-off filter (6), the transmitted light and the emitted light are combined into one beam, and enter the first Three cut-off filters (7), reflected by the third cut-off filter (7), while the laser light emitted by the fourth fiber laser (4) is transmitted through the third cut-off filter (7), the transmitted light and reflection The photosynthesis is a beam of output, that is, the four beams of laser beams are combined. 10. The spectrum synthesis method based on a dichroic mirror 45° incident spectrum synthesis device according to claim 9, characterized in that: the first cut-off filter (5) and the first fiber laser (1) emit The included angle of the laser light is 45°; the included angle of the second cut-off filter (6) and the laser light emitted by the third laser fiber laser (3) is 45°; the third cut-off filter (7) The included angle with the laser emitted by the third laser fiber laser (3) is 45°.