CN204230626U - Broadband tunable continuous wave 530-780nm optical parametric oscillator - Google Patents

Abstract

The utility model is a wide-band tunable continuous wave 530-780nm optical parametric oscillator, which uses a semiconductor laser array to drive a near-infrared laser light source and performs frequency doubling on it to generate a short-wavelength visible light laser, further driving the optical parametric oscillator-frequency doubling, Enabling a wide tuning range of visible laser output with all solid-state components makes the laser system feasible for medical applications and scientific research from a standpoint of cost, volume, reliability, stability and durability. By adopting the technical scheme of the utility model, it is possible to obtain a wide-band tunable continuous wave visible light output with a spectral range covering 530-780nm while reducing the system threshold, improving the conversion efficiency from near-infrared to visible light, and reducing costs.

Description

Broadband Tunable CW 530-780nm Optical Parametric Oscillator

technical field

The utility model belongs to the field of optoelectronics and laser technology, and relates to an all-solid-state continuous wave visible light wide-band tunable optical parametric oscillator laser, which is suitable for laser medicine, medical microscopic imaging, laser spectroscopy, precision optical measurement and scientific research, etc. field applications.

Background technique

Lasers in the visible light band have important application value in the fields of spectral analysis, quantum mechanics, information processing, atomic physics, biomedical imaging, ultra-high resolution microscopy and medical treatment. Especially because the deoxygenated hemoglobin in the blood reaches the peak value of the molar extinction coefficient at 580nm, while the oxygenated hemoglobin reaches the peak value at 550nm and 600nm; The ~780nm band is almost transparent; the 618~780nm band is just in the range of the optical window (618~1316nm) of biological tissue. Therefore, for applications such as biomedical imaging, laser medical treatment, and the study of the interaction between light and biological tissue, the choice is between 530~ A suitable continuous wave laser source in the 780nm wavelength range is of great significance for improving imaging quality, treatment efficiency, penetration depth and reducing photoinduced tissue damage. At present, lasers in the visible light band are mainly output directly by lasers such as semiconductor lasers, solid-state lasers, gas lasers, dye lasers, and fiber lasers, or through nonlinear frequency conversion technologies such as frequency doubling, sum frequency, and difference frequency. However, these lasers And technical means can only obtain the output of certain specific wavelength lasers. Among them, the output spectral range of the titanium-sapphire laser with a wide output wavelength tunable range can only reach 660~1180nm, which cannot cover the 530~660nm band of visible light. The optical parametric oscillator, which uses second-order nonlinear optical mixing to realize optical frequency conversion, has a wide tuning range, from ultraviolet to far infrared, which makes up for the defect that ordinary lasers and their frequency multipliers can only output lasers of certain wavelengths. An important approach to broadband tunable, highly coherent radiation sources and new-band laser systems. Optical parametric oscillators have been successfully applied in the mid-infrared band, but there are few public reports in the visible band, and most of them focus on the pulse pumping operation mode. The continuous wave pumped optical parametric oscillator has a higher oscillation threshold than other modes of operation, requiring the pump source to provide higher pump power, and the nonlinear crystal also has a larger nonlinear coefficient, so the continuous wave Realization of wave-optical parametric oscillators is more difficult than other operating mode optical parametric oscillators.

Utility model content

In order to overcome the lack of a wide-band tunable continuous wave laser in the existing visible light band, the utility model provides a continuous wave optical parametric oscillator system, the continuous wave optical parametric oscillator system can output a wide band within the visible light band Tunable laser.

In order to achieve the above-mentioned technical purpose and achieve the above-mentioned technical effect, the utility model is realized through the following technical solutions:

Broadband tunable continuous wave 530-780nm optical parametric oscillator, including pump laser, beam coupling system I, input mirror I, laser crystal, reflector I, frequency doubling nonlinear crystal I, output mirror I, reflector II, beam coupling system II, input mirror II, optical parametric oscillator nonlinear crystal, reflector III, reflector IV, optical parametric oscillator-frequency doubling nonlinear crystal II, output mirror II, the The input mirror I, the reflection mirror I and the output mirror I form the resonant cavity of the short-wavelength laser, and the beam coupling system I is located between the pump laser and the input mirror I, and the central axis of the beam coupling system I is in the same direction as the pump laser. Coincidentally, the laser crystal is located between the input mirror I and the reflector I, and the frequency doubling nonlinear crystal I is located between the reflector I and the output mirror I, the input mirror II, the reflector III, the reflector IV, and the output mirror II, A resonant cavity constituting a visible light optical parametric oscillator, the beam coupling system II is located between the mirror II and the input mirror II, the central axis of the beam coupling system II coincides with the reflected light direction of the mirror II, and the optical parametric oscillator nonlinear crystal Located between the input mirror II and the mirror III, the optical parametric oscillator-frequency doubling nonlinear crystal II is located between the mirror IV and the output mirror II;

The pump laser light emitted by the pump laser is incident on the input mirror I after passing through the beam coupling system I, and the pump laser light transmitted through the input mirror I is incident on the laser crystal, and the laser crystal converts the pump laser light into near-infrared laser light, from The near-infrared laser emitted by the laser crystal is incident on the mirror I, and the near-infrared laser reflected by the mirror I is incident on the frequency-doubled nonlinear crystal I, and the frequency-doubled nonlinear crystal I converts the near-infrared laser into a short-wavelength visible laser, The short-wavelength visible laser emitted from the frequency-doubling nonlinear crystal I is incident on the output mirror I, and the near-infrared laser transmitted from the frequency-doubling nonlinear crystal I is reflected by the output mirror I and then incident on the frequency-doubling nonlinear crystal I. The near-infrared laser transmitted by the nonlinear crystal I enters the mirror I, the near-infrared laser reflected by the mirror I enters the input mirror I and continues to oscillate in the resonant cavity, and the short-wavelength visible laser emitted by the output mirror I enters the reflector Mirror II, the short-wave visible laser reflected by the mirror II enters the beam coupling system II, the short-wave visible laser transmitted by the beam coupling system II enters the input mirror II, and the short-wave visible laser transmitted by the input mirror II enters the optical parameter oscillation The nonlinear crystal of the optical parametric oscillator converts the short-wave visible laser into a wide-band near-infrared laser. The broadband near-infrared laser emitted by the nonlinear crystal of the parametric oscillator is incident on the mirror III, and the broadband near-infrared laser reflected by the mirror III is incident on the optical parametric oscillator-frequency doubling nonlinear crystal II, and the optical parametric oscillator-times The frequency nonlinear crystal II converts the broadband near-infrared laser into a broadband visible laser, and the broadband visible laser emitted from the optical parametric oscillator-frequency doubling nonlinear crystal II enters the output mirror II and transmits to the optical parameter through the output mirror II Outside the oscillator-frequency-doubling resonant cavity, the broadband near-infrared laser transmitted from the optical parametric oscillator-frequency-doubling nonlinear crystal II is incident on the output mirror II, and the broadband near-infrared laser reflected by the output mirror II is incident on the input mirror II And continue to oscillate in the optical parametric oscillator-frequency doubling resonant cavity.

Further, the pump laser is a semiconductor laser, and the center wavelength of the laser is 800-900nm.

Further, the beam coupling system I is at least one of a geometric coupling system and a spectral coupling system; the beam coupling system I is at least one of a lens, a spatial filter, an optical isolator, a grating, and a multimode fiber .

Further, the plane of the input mirror 1 facing the beam coupling system 1 is coated with an 800-900nm antireflection coating, and the other side of the input mirror 1 is coated with an 800-900nm antireflection coating and a 400-540nm and 1 μm high reflection coating; The mirror I facing the short-wavelength visible laser resonator is coated with a 400-540nm and 1 μm high-reflection film; the output mirror I is coated with a 400-540nm anti-reflective and 1 μm high-reflection film facing the mirror of the short-wavelength visible laser resonator , the other side of the output mirror I is plated with a 400-540nm anti-reflection coating.

Further, the laser crystal is a neodymium-doped ion single crystal or ceramics, and the shape of the laser crystal is any one of cylinder, slab, hexahedral, waveguide, disc, and fiber; The two transparent surfaces of the crystal are coated with 400-540nm anti-reflection, 800-900nm anti-reflection and 1μm anti-reflection coatings.

Further, the frequency-doubling nonlinear crystal I is potassium niobate, barium metaborate, bismuth borate, lithium triborate, potassium niobate, potassium titanyl phosphate, periodically poled lithium niobate, periodically poled titanium phosphate Any one of the oxypotassium crystals; the two light-passing surfaces of the frequency-doubling nonlinear crystal I are coated with 400-540nm anti-reflection, 800-900nm anti-reflection and 1 μm anti-reflection coatings.

Further, the mirror surface of the mirror II facing the output mirror I is coated with a 400-540nm high-reflection film; the beam coupling system II is at least one of a geometric coupling system and a spectral coupling system; the beam coupling system System II is at least one of a lens, a spatial filter, an optical isolator, a half-wave plate, a grating, and a multimode fiber.

Further, the mirror surface of the input mirror II facing the beam coupling system II is coated with a 400-540nm anti-reflection coating, and the other side of the input mirror II is coated with a 400-540nm anti-reflection coating and a near-infrared high-reflection coating; the reflector The mirror surface of III towards the inner side of the resonant cavity is coated with a 400-540nm partial transmission and near-infrared high-reflection film; the mirror IV is coated with a 400-540nm partial transmission and near-infrared high-reflection film towards the inner side of the resonant cavity; the output mirror The mirror surface of II facing the inner side of the resonant cavity is coated with near-infrared partial transmission and 530-800nm anti-reflection coating, and the other side of the output mirror II is coated with near-infrared anti-reflection coating and 530-800nm anti-reflection coating.

Further, the nonlinear crystal of the optical parametric oscillator is any one of a single crystal and multiple cascades; the nonlinear crystal of the optical parametric oscillator is a periodically polarized stoichiometric ratio lithium tantalate, a periodic Any one of poled lithium niobate, periodically poled magnesium oxide-doped lithium niobate, periodically poled potassium titanyl phosphate, and periodically poled rubidium titanyl arsenate; the optical parametric oscillator nonlinear crystal The two transparent surfaces of the optical parametric oscillator are coated with 400-540nm anti-reflection and near-infrared anti-reflection coatings; the nonlinear crystal of the optical parametric oscillator adopts a quasi-phase matching method; the nonlinear crystal of the optical parametric oscillator is a room temperature, temperature-controlled furnace Any of the temperature control states.

Further, the optical parametric oscillator-frequency doubling nonlinear crystal II is potassium niobate, barium metaborate, bismuth borate, lithium triborate, potassium niobate, potassium titanyl phosphate, periodically poled lithium niobate, periodic Any one of the polarized potassium titanyl phosphate crystals; the two light-transmitting surfaces of the optical parametric oscillator-frequency doubling nonlinear crystal II are coated with 400-800nm anti-reflection and near-infrared anti-reflection coatings.

The beneficial effects of the utility model are:

The wide-band tunable continuous wave 530-780nm visible light optical parametric oscillator described in the utility model adopts all-solid-state structure, short-wavelength visible light pumping and frequency doubling in the resonant cavity, which can reduce the system threshold and improve near-infrared The wide-band tunable continuous wave visible light output can be obtained under the condition of reducing the conversion efficiency of visible light and reducing the cost, and the spectral range covers 530-780nm.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Explanation of symbols in the figure: 1. Pump laser, 2. Beam coupling system I, 3. Input mirror I, 4. Laser crystal, 5. Reflector I, 6. Frequency-doubling nonlinear crystal I, 7. Output mirror I, 8. Mirror II, 9. Beam coupling system II, 10. Input mirror II, 11. Optical parametric oscillator nonlinear crystal, 12. Mirror III, 13. Mirror IV, 14. Optical parametric oscillator - frequency doubling Nonlinear Crystals II, 15. Output Mirrors II.

Detailed ways

The utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

In order to solve the problem that the laser output wavelength tuning range cannot cover the visible light band, the embodiment of the utility model provides a wide-band tunable continuous wave 530-780 nm visible light optical parametric oscillator system. The utility model uses a short-wavelength visible light laser pump The quasi-phase-matched optical parametric oscillator is used to double the frequency of its idler light to obtain visible light laser output. The advantage of this is that the all-solid-state structure makes the laser relatively compact and stable, and the quasi-phase-matched can take advantage of the maximum nonlinearity of the nonlinear crystal Linear coefficient, and can adjust the power density of the idler light in the cavity to maximize the frequency doubling efficiency, thereby improving the overall conversion efficiency, and at the same time obtain a wide-band tunable continuous wave visible laser output through a variety of tuning methods, the following is preferred Embodiment illustrates the utility model in more detail:

Referring to Figure 1, the wide-band tunable visible light optical parametric oscillator-frequency multiplication includes a pump laser 1, a beam coupling system I2, an input mirror I3, a laser crystal 4, a mirror I5, and a frequency multiplication device sequentially arranged on the optical path. Nonlinear crystal I6, output mirror I7, mirror II8, beam coupling system II9, input mirror II10, optical parametric oscillator nonlinear crystal 11, mirror III12, mirror IV13, optical parametric oscillator - frequency doubling nonlinear crystal II14 , output mirror II15, described input mirror I3, reflecting mirror I5 and output mirror I7 constitute the resonant cavity of short-wavelength laser, beam coupling system I2 is positioned between pumping laser 1 and input mirror I3, the center of described beam coupling system I2 The axis coincides with the light output direction of the pump laser 1, the laser crystal 4 is located between the input mirror I3 and the reflector I5, the frequency-doubling nonlinear crystal I6 is located between the reflector I5 and the output mirror I7, the input mirror II10, the reflector III12, mirror IV13, and output mirror II15 constitute the resonant cavity of the visible light optical parametric oscillator, and the beam coupling system II9 is located between the mirror II8 and the input mirror II10, and the central axis of the beam coupling system II9 and the reflected light of the mirror II8 The directions coincide, the optical parametric oscillator nonlinear crystal 11 is located between the input mirror II10 and the reflecting mirror III12, and the optical parametric oscillator-frequency doubling nonlinear crystal II14 is located between the reflecting mirror IV13 and the output mirror II15.

In this embodiment, the pump laser 1 is a semiconductor laser with a central wavelength of 808nm, and the 808nm laser is transmitted to the beam coupling system I2 through an energy-transmitting optical fiber with a core diameter of 200 μm and a numerical aperture of 0.22. The beam coupling system I2 is a geometric coupling system composed of two plano-convex lenses with a focal length of 40mm, both the plane and the curved surface are coated with an 808nm anti-reflection coating (the transmittance is greater than 99%), which can couple and focus the 808nm laser to short-wavelength visible laser resonance cavity.

The laser resonator consists of an input mirror I3, a reflection mirror I5 and an output mirror I7. The input mirror I3 is a plano-concave mirror with a radius of curvature of 200mm. The plane facing the beam coupling system I2 is coated with an 808nm anti-reflection film. One side is coated with 808nm anti-reflection coating (transmission rate greater than 99%) and 532nm and 1064nm high reflection coating (reflection rate is greater than 99.8%); mirror I5 is a flat mirror, and the mirror surface facing the resonant cavity is coated with 532nm and 1064nm high reflection coating; The output mirror I7 is a plano-concave mirror with a radius of curvature of 200mm. The mirror facing the short-wavelength resonator is coated with a 532nm anti-reflection and 1064nm high-reflection coating, and the other side is coated with a 532nm anti-reflection coating. The laser crystal 4 is placed between the input mirror I3 and the reflection mirror I5. It is a bonded Nd:YVO4 crystal with a doping concentration of 1% in a strip shape. The crystal size is 3×3×(2+10) mm. The transparent surface is coated with 532nm anti-reflection, 808nm anti-reflection and 1064nm anti-reflection coatings; 808nm pump light passes through the laser crystal to generate 1064nm laser. Using bonded crystal can effectively reduce the thermal lens effect of the crystal. The frequency doubling nonlinear crystal I6 is placed between the reflector I5 and the output mirror I7. It is a strip-shaped lithium triborate crystal with a crystal size of 3×3×10mm and a cutting angle of 11.4°. Both ends of the transparent surface are coated with 532nm , 808nm and 1064nm anti-reflection coatings, when the 1064nm laser passes through the lithium triborate crystal, it is converted into a 532nm laser through type I phase matching.

Mirror II8 is a plane mirror, and the mirror surface facing output mirror I7 is coated with a 532nm high-reflection film, and reflects the 532nm laser output through output mirror I7 to beam coupling system II9. The beam coupling system II9 is a geometric coupling system composed of a lens with a focal length of 70mm and a half-wave plate, which can control the polarization of the 532nm laser and the diameter of the coupling spot to achieve mode matching with the oscillating light.

The input mirror II10, the reflection mirror III12, the reflection mirror IV13 and the output mirror II15 constitute an optical parametric oscillator and its frequency doubling resonant cavity. Among them, the input mirror II10 is a plano-concave mirror with a radius of curvature of 200mm. The mirror surface facing the beam coupling system II9 is coated with a 532nm anti-reflection coating (the transmittance is greater than 96%), and the other side is coated with a 532nm anti-reflection coating (the transmittance is greater than 96%) and 800-1560nm high-reflection film (reflectivity greater than 99.8%); mirror III12 is a plano-concave mirror with a radius of curvature of 200mm, and the mirror surface facing the inside of the resonator is coated with 532nm partial transmission (transmittance greater than 90%) ) and 800-1560nm high-reflection film; mirror IV13 is a plane mirror, and the mirror surface facing the inside of the resonator is coated with 800-1560nm high-reflection film; the output mirror II15 is a plane mirror, and the mirror surface facing the inside of the resonator is coated with 1060-1560nm partial transmission (transmission The transmission rate is greater than 90%) and 530-800nm anti-reflection coating (transmission rate is greater than 98%), and the other side is coated with 1060-1560nm anti-reflection coating and 530-800nm anti-reflection coating (transmission rate is greater than 98%).

The optical parametric oscillator nonlinear crystal 11 is a monolithic multi-period periodic polarization stoichiometric ratio doped magnesium oxide lithium tantalate crystal, the crystal size is 0.5×8.2×30mm, the polarization period is 8.0-8.7μm, and the number of periods is 12. Both ends of the crystal are coated with 532nm anti-reflection and 800-1560nm anti-reflection coatings (the transmittance is greater than 98%), and the optical parametric oscillator adopts the combined tuning technology of quasi-phase matching method and period tuning and temperature tuning .

Optical parametric oscillator-frequency doubling nonlinear crystal II14 is a periodically poled lithium niobate crystal, the crystal size is 0.5×12×40mm, the polarization period is 6.5-21.2μm, the number of periods is 32, and the light at both ends of the crystal The surface is coated with 400-800nm anti-reflection and 800-1560nm anti-reflection coating (the transmittance is greater than 98%).

Principle of the utility model:

The pump laser 1 outputs laser light with a wavelength of 800-900nm. The pump laser enters the short-wavelength visible laser resonator composed of the input mirror I3, the reflector I5 and the output mirror I7 after passing through the beam coupling system I2. The pump laser The pump laser passes through the input mirror I3, the laser crystal 4, the mirror I5, the frequency-doubling nonlinear crystal I6 and the output mirror I7 sequentially in the short-wavelength visible laser resonator, and the laser crystal 4 generates near-infrared laser under the action of the pump laser. The near-infrared laser is reflected by the mirror I5 and enters the frequency-doubled nonlinear crystal I6, and the frequency-doubled nonlinear crystal I6 generates a short-wavelength visible light laser under the action of the near-infrared laser, and the short-wavelength visible light laser is transmitted through the output mirror I7 to the Outside the short-wavelength visible laser resonator, part of the near-infrared laser transmitted through the frequency-doubling nonlinear crystal I6 is reflected by the output mirror I7, the reflector I5 and the input mirror I3, and oscillates in the short-wavelength visible laser resonator. The short-wavelength visible laser outside the short-wavelength visible laser resonator is reflected by the mirror II8 to the beam coupling system II9, and after passing through the beam coupling system II9, the short-wavelength visible laser enters the input mirror II10, mirror III12, mirror IV13 and The optical parametric oscillator-frequency doubling resonant cavity composed of the output mirror II15, the short-wavelength visible light laser in the optical parametric oscillator-frequency doubling resonant cavity sequentially passes through the optical parametric oscillator nonlinear crystal 11 and the mirror III12 and then transmits to the optical Parametric oscillator-outside the frequency doubling resonant cavity, the nonlinear crystal 11 of the optical parametric oscillator generates a wide-band tunable near-infrared laser under the action of a short-wavelength visible laser, and the wide-band tunable near-infrared laser is sequentially reflected by mirror III12 And reflective mirror IV13 reflection, optical parametric oscillator-frequency doubling nonlinear crystal II14 transmission, and output mirror II15 and input mirror II10 reflection, oscillate in the optical parametric oscillator-frequency doubling resonant cavity, optical parametric oscillator-frequency doubling nonlinear The linear crystal II14 generates a broadband tunable visible light laser under the action of a broadband tunable near-infrared laser, and the broadband tunable visible laser is transmitted through the output mirror II15 to the outside of the optical parametric oscillator-frequency doubling resonant cavity.

The optical parametric oscillator is pumped by short-wave visible light, and its frequency is doubled while increasing the power density of the idler frequency in the resonant cavity of the optical parametric oscillator, so as to obtain a high-efficiency continuous wave wide-band tunable visible light laser output.

Those skilled in the art can understand that the accompanying drawing is only a schematic diagram of a preferred embodiment, and the above-mentioned embodiments of the present invention are only for description, and do not represent the advantages and disadvantages of the embodiments.

The above descriptions are only preferred embodiments of the utility model, and are not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (10)

1. A wide-band tunable continuous wave 530-780nm optical parametric oscillator, characterized in that it includes a pump laser (1), a beam coupling system I (2), an input mirror I (3), and Laser crystal (4), mirror I (5), frequency doubling nonlinear crystal I (6), output mirror I (7), mirror II (8), beam coupling system II (9), input mirror II (10 ), optical parametric oscillator nonlinear crystal (11), mirror III (12), mirror IV (13), optical parametric oscillator-frequency doubling nonlinear crystal II (14), output mirror II (15), and The input mirror I (3), reflecting mirror I (5) and output mirror I (7) constitute a short-wavelength laser resonant cavity, and the central axis of the beam coupling system I (2) is connected to the output light of the pump laser (1) The directions coincide, the input mirror II (10), mirror III (12), mirror IV (13), and output mirror II (15) constitute a resonant cavity of a visible light optical parametric oscillator, and the beam coupling system II (9 ) The central axis coincides with the reflected light direction of the reflector II (8); The pump laser light emitted by the pump laser (1) is incident on the input mirror I (3) after passing through the beam coupling system I (2), and the pump laser light transmitted through the input mirror I (3) is incident on the laser crystal (4 ), the laser crystal (4) converts the pump laser into a near-infrared laser, and the near-infrared laser emitted from the laser crystal (4) is incident on the mirror I (5), and the near-infrared laser reflected by the mirror I (5) The laser is incident on the frequency-doubling nonlinear crystal I (6), and the frequency-doubling nonlinear crystal I (6) converts the near-infrared laser into a short-wavelength visible light laser, and the short-wavelength visible light emitted from the frequency-doubling nonlinear crystal I (6) The laser is incident on the output mirror I (7), and the near-infrared laser transmitted from the frequency-doubling nonlinear crystal I (6) is reflected by the output mirror I (7) and then enters the frequency-doubling nonlinear crystal I (6). The near-infrared laser transmitted by the nonlinear crystal I (6) is incident on the mirror I (5), and the near-infrared laser reflected by the mirror I (5) is incident on the input mirror I (3) and continues to oscillate in the resonant cavity. The short-wavelength visible light laser emitted by the output mirror I (7) is incident on the reflector II (8), and the short-wavelength visible light laser reflected by the reflector II (8) is incident on the beam coupling system II (9), and passes through the beam coupling system II (9 ), the short-wave visible laser light transmitted by the input mirror II (10) is incident on the input mirror II (10), the short-wave visible light laser transmitted by the input mirror II (10) is incident on the nonlinear crystal of the optical parametric oscillator (11), and the nonlinear crystal of the optical parametric oscillator (11 ) to convert the short-wave visible laser into a wide-band near-infrared laser, and the short-wave visible laser transmitted from the optical parametric oscillator nonlinear crystal (11) is transmitted to the outside of the resonant cavity through the mirror III (12), and the optical parametric oscillator nonlinear The broadband near-infrared laser emitted by the crystal (11) is incident on the mirror III (12), and the broadband near-infrared laser reflected by the mirror III (12) is incident on the optical parametric oscillator-frequency-doubling nonlinear crystal II (14) , the optical parametric oscillator-frequency-doubling nonlinear crystal II (14) converts the broadband near-infrared laser into a broadband visible laser, and the broadband visible laser emitted from the optical parametric oscillator-frequency-doubling nonlinear crystal II (14) is incident To the output mirror II (15) and transmitted through the output mirror II (15) to the outside of the optical parametric oscillator-frequency doubling resonator, the broadband near-infrared laser transmitted from the optical parametric oscillator-frequency doubling nonlinear crystal II (14) Incident to the output mirror II (15), the broadband near-infrared laser reflected by the output mirror II (15) enters the input mirror II (10) and continues to oscillate in the optical parametric oscillator-frequency doubling resonant cavity. 2. The broadband tunable continuous wave 530-780nm optical parametric oscillator according to claim 1, characterized in that the pump laser (1) is a semiconductor laser, and the center wavelength of the laser is 800-900nm . 3. The broadband tunable continuous wave 530-780nm optical parametric oscillator according to claim 1, characterized in that, the beam coupling system I (2) is at least one of a geometric coupling system and a spectral coupling system ; The beam coupling system I (2) is at least one of a lens, a spatial filter, an optical isolator, a grating, and a multimode fiber. 4. The broadband tunable continuous wave 530-780nm optical parametric oscillator according to claim 1, characterized in that, the plane of the input mirror I (3) facing the beam coupling system I (2) is coated with 800- 900nm anti-reflection coating, the other side of the input mirror I (3) is coated with an 800-900nm anti-reflection coating and a 400-540nm and 1μm high-reflection coating; the mirror I (5) faces the mirror surface of the short-wavelength visible laser resonator Coated with 400-540nm and 1μm high-reflection film; the mirror surface of the output mirror I (7) facing the short-wavelength visible laser resonator is coated with 400-540nm anti-reflection and 1 μm high-reflection film, the output mirror I (7) The other side is coated with 400-540nm AR coating. 5. The broadband tunable continuous wave 530-780nm optical parametric oscillator according to claim 1, characterized in that the laser crystal (4) is a neodymium-doped ion single crystal or ceramic, and the laser crystal (4) The shape of the laser crystal (4) is any one of cylindrical, slat-shaped, hexahedral, waveguide-shaped, disc-shaped, and fiber-shaped; the two transparent surfaces of the laser crystal (4) are coated with 400-540nm anti-reflection, 800 -900nm anti-reflection and 1μm anti-reflection coating. 6. The broadband tunable continuous wave 530-780nm optical parametric oscillator according to claim 1, characterized in that, the frequency-doubling nonlinear crystal I (6) is potassium niobate, barium metaborate, bismuth borate , lithium triborate, potassium niobate, potassium titanyl phosphate, periodically poled lithium niobate, periodically poled potassium titanyl phosphate crystal; two of the frequency-doubling nonlinear crystal I (6) The first transparent surface is coated with 400-540nm anti-reflection, 800-900nm anti-reflection and 1μm anti-reflection coating. 7. The broadband tunable continuous wave 530-780nm optical parametric oscillator according to claim 1, characterized in that, the mirror surface of the mirror II (8) facing the output mirror I (7) is coated with 400- 540nm high reflection film; the beam coupling system II (9) is at least one of a geometric coupling system and a spectral coupling system; the beam coupling system II (9) is a lens, a spatial filter, an optical isolator, At least one of a half-wave plate, a grating, and a multimode fiber. 8. The broadband tunable continuous wave 530-780nm optical parametric oscillator according to claim 1, characterized in that, the mirror surface of the input mirror II (10) facing the beam coupling system II (9) is coated with 400- 540nm anti-reflection coating, the other side of the input mirror II (10) is coated with a 400-540nm anti-reflection coating and a near-infrared high-reflection coating; the mirror surface of the mirror III (12) facing the inside of the resonant cavity is coated with a 400-540nm part Transmitting and near-infrared high-reflection film; the mirror surface of the mirror IV (13) facing the inside of the resonant cavity is coated with a 400-540nm partial transmission and near-infrared high-reflection film; the output mirror II (15) is facing the mirror surface inside the resonant cavity It is coated with near-infrared partial transmission and 530-800nm anti-reflection film, and the other side of the output mirror II (15) is coated with near-infrared anti-reflection film and 530-800nm anti-reflection film. 9. The broadband tunable continuous wave 530-780nm optical parametric oscillator according to claim 1, characterized in that the nonlinear crystal (11) of the optical parametric oscillator is a single crystal and multiple cascaded Any one of: the optical parametric oscillator nonlinear crystal (11) is periodically poled stoichiometric lithium tantalate, periodically poled lithium niobate, periodically poled magnesium oxide doped lithium niobate, periodically Any one of poled potassium titanyl phosphate and periodically poled rubidium titanyl arsenate; the two transparent surfaces of the optical parametric oscillator nonlinear crystal (11) are coated with 400-540nm anti-reflection and near-infrared Anti-reflection coating; the optical parametric oscillator nonlinear crystal (11) adopts a quasi-phase matching method; the optical parametric oscillator nonlinear crystal (11) is in any one of room temperature and temperature control furnace temperature control states. 10. The wide-band tunable continuous wave 530-780nm optical parametric oscillator according to claim 1, characterized in that the optical parametric oscillator-frequency doubling nonlinear crystal II (14) is potassium niobate, partial Any one of barium borate, bismuth borate, lithium triborate, potassium niobate, potassium titanyl phosphate, periodically poled lithium niobate, and periodically poled potassium titanyl phosphate crystal; the optical parametric oscillator-time The two transparent surfaces of the frequency nonlinear crystal II (14) are coated with 400-800nm anti-reflection and near-infrared anti-reflection coatings.