A cavity-dumped laser with orthogonal polarization output based on corner cube

Abstract

The invention relates to the technical field of solid lasers, and discloses an orthogonal polarization output cavity dumping laser based on a corner cube prism. The laser comprises a pump source, a first polarizer, a second polarizer, a Ho:YLF crystal, an RTP crystal, a third polarizer, a first half-wave plate, a first corner cube prism, a first right-angle prism, a second corner cube prism, a second right-angle prism and a second half-wave plate; two corner cube prisms and two right-angle prisms constitute a ring resonant cavity, the two corner cube prisms are arranged in the same manner, linear polarized light with a special polarization azimuth passes through the two corner cube prisms in four different reflection orders respectively, so as to achieve a polarization-maintaining effect, and cavity dumping laser output can be achieved by coordinating with the voltage rise and fall time of the RTP crystal, and the two polarizers are respectively used as output mirrors of vertical polarized light and horizontal polarized light, so as to obtain orthogonal polarization synchronous output pulse laser with high peak power, large energy and high stability.

Description

Technical Field

[0001] The invention relates to the technical field of solid lasers, in particular to an orthogonal polarization output cavity dumping laser based on a corner cube prism. Background Art

[0002] Pulsed lasers with synchronous output of orthogonal polarizations can be used in many fields such as communication systems, laser radar, and medical treatment. However, the current cavity-dumped lasers with ordinary cavity mirror structures usually output lasers with a single polarization, and it is difficult to achieve dual-polarization laser output, or use polarization switches to achieve output switching of two lasers with different polarizations, but the delay time may cause the laser polarization degree to decrease, resulting in instability of the laser system. In addition, under special conditions such as mechanical vibration and temperature changes, the resonant cavity of the ordinary cavity mirror structure (such as the flat cavity) is prone to detuning, resulting in unstable laser output energy and changes in the laser output direction.

[0003] Therefore, improving the anti-detuning ability of cavity dumped lasers and obtaining orthogonal polarization synchronous output pulse lasers with high peak power, large energy and high stability has become a research hotspot for cavity dumped solid-state lasers. Summary of the invention

[0004] In order to solve the deficiencies mentioned in the above background technology, the purpose of the present invention is to provide an orthogonal polarization output cavity dumping laser based on corner cube prisms, wherein the laser comprises a pump source, a first polarizer, a second polarizer, a Ho:YLF crystal, an RTP crystal, a third polarizer, a first half-wave plate, a first corner cube prism, a first right-angle prism, a second corner cube prism, a second right-angle prism and a second half-wave plate; two corner cube prisms and two right-angle prisms constitute a ring resonant cavity, the two corner cube prisms are arranged in the same manner, linearly polarized light with a special polarization azimuth passes through the two corner cube prisms in four different reflection orders respectively, and the polarization-maintaining effect can be achieved, and the cavity dumping laser output can be achieved by coordinating the boost and buck time of the RTP crystal, and the two polarizers are respectively used as output mirrors of vertically polarized light and horizontally polarized light, and an orthogonal polarization synchronous output pulse laser with high peak power, large energy and high stability can be obtained.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] An orthogonal polarization output cavity dumping laser based on a corner cube prism, the laser comprising a pump source, a first polarizer, a second polarizer, a Ho:YLF crystal, an RTP crystal, a third polarizer, a first half-wave plate, a first corner cube prism, a first right-angle prism, a second corner cube prism, a second right-angle prism and a second half-wave plate;

[0007] The first polarizer is a pump light injection mirror, and the second polarizer and the third polarizer are output mirrors for vertically polarized pulse light and horizontally polarized pulse light, respectively;

[0008] The RTP crystal acts as an electro-optical Q switch to achieve cavity emptying laser output;

[0009] The first corner cube prism, the first right-angle prism, the second corner cube prism and the second right-angle prism form a ring resonant cavity, and the first corner cube prism and the second corner cube prism are arranged in the same manner and are both on the same side of the optical axis. The first right-angle prism and the second right-angle prism are adjacent and are both on the same side of the optical axis.

[0010] Furthermore, the first polarizer and the third polarizer have high reflection for 1.94 μm pump light, high reflection for 2.05 μm horizontal polarized light, and high transmission for 2.05 μm vertical polarized light, and the second polarizer has high reflection for 1.94 μm pump light, high reflection for 2.05 μm vertical polarized light, and high transmission for 2.05 μm horizontal polarized light.

[0011] Furthermore, the length and width of the RTP crystal are both 2mm-20mm, the thickness is 2mm-50mm, and the light-transmitting surface is coated with a 2.05μm high-transmittance film.

[0012] Furthermore, the incident surface diameters of the first corner cube prism and the second corner cube prism are both 20mm-2000mm, the incident surfaces are coated with 1.9μm-2.1μm high-transmittance films, the curvature radius of the reflective surface is 0-2000mm, and the material is JGS3.

[0013] Furthermore, the diameters of the first half-wave plate and the second half-wave plate are both 8 mm-1000 mm, and both sides are coated with 2.05 μm high-transmittance film.

[0014] Furthermore, the thickness of the hypotenuse of the incident surface of the first right-angle prism and the second right-angle prism is 5mm-1000mm, the length of the right-angle side and the hypotenuse is 5mm-1000mm, and the hypotenuse of the incident surface is coated with a 1.9μm-2.1μm high-transmittance film made of JGS3.

[0015] Furthermore, when the rotation angles of the first half-wave plate and the second half-wave plate are coordinated so that the polarization azimuth of the linear polarized light before the incident corner cube prism becomes 16.06°, 43.94°, 46.06° and 73.94° respectively, the emergent light and the incident light are polarized in the same state after passing through the first corner cube prism and the second corner cube prism in four different reflection orders (ACB and BCA, BCA and ACB, BAC and CAB, CAB and BAC), thereby achieving the effect of polarization maintaining.

[0016] Beneficial effects of the present invention:

[0017] The present invention designs an orthogonal polarization output cavity dumping laser based on corner cube prisms. Two corner cube prisms and two right-angle prisms constitute a ring resonant cavity. The two corner cube prisms are arranged in the same way. Linear polarized light with a special polarization azimuth passes through the two corner cube prisms in four different reflection orders, respectively, so as to achieve the effect of polarization maintenance. In combination with the voltage rise and fall time of the RTP crystal, cavity dumping laser output can be achieved. Two polarizers are respectively used as output mirrors of vertically polarized light and horizontally polarized light, so as to obtain orthogonal polarization synchronous output pulse laser with high peak power, large energy and high stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described below in conjunction with the accompanying drawings.

[0019] Figure 1 It is a schematic diagram of the structure of the orthogonal polarization output cavity dumping laser based on corner cube prism of the present invention;

[0020] Figure 2 It is a schematic diagram of the pyramid coordinate system of the present invention;

[0021] Figure 3 is the relationship between the polarization azimuth of the incident light and the polarization state of the outgoing light when the reflection order of the corner cube prism of the present invention is ACB;

[0022] Figure 4 It is the relationship between the polarization azimuth of the incident light and the polarization state of the outgoing light when the reflection order of the corner cube prism of the present invention is BAC. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] like Figure 1-Figure 4 As shown, the Jones vector is used to represent the polarization state of the plane wave. The Jones matrix operation can be used to obtain the polarization state of the outgoing light after the incident light beam passes through 6 different reflection orders in the corner cube prism. The Jones vectors of the incident light and the outgoing light are represented by E in and E out , both satisfy formulas (1) and (2).

[0025]

[0026]

[0027] α is the angle between the electric vector of the incident light and the x-axis of the coordinate system; δ is the two components of the Jones vector Ex and E y The phase difference;

[0028] The light beam undergoes six different reflection orders in the corner cube prism, and the corresponding Jones matrices are formulas (3)-(8):

[0029] J ABC =T(150)·R·T(60)·R·T(-60)·R·T(30) (3)

[0030] J CBA =T(30)·R·T(-60)·R·T(60)·R·T(150) (4)

[0031] J BCA =T(-90)·R·T(60)·R·T(-60)·R·T(150) (5)

[0032] J ACB =T(150)·R·T(-60)·R·T(60)·R·T(-90) (6)

[0033] J CAB =T(30)·R·T(60)·R·T(-60)·R·T(-90) (7)

[0034] J BAC =T(-90)·R·T(-60)·R·T(60)·R·T(30) (8)

[0035] Assuming that the reflection order of the incident light on the three reflection surfaces in the corner cube is ACB, the Jones matrix corresponding to the corner cube is J ACB , the outgoing light will be Figure 1 The BCA region emits, and the corresponding Jones vector can be expressed as formula (9):

[0036] E out =F·J ACB ·E in (9)

[0037] Where F is the coordinate inversion matrix, indicating that the directions of the incident light and the outgoing light are opposite.

[0038]

[0039] Assuming that the light entering the corner cube prism is linearly polarized light with zero phase difference, the reflection order of the incident light on the three reflection surfaces in the corner cube prism is ACB. Figure 3The figure shows the change of the phase difference of the Jones component of the light emitted from the BCA region and the change of the polarization azimuth α2 of the emitted light when the polarization azimuth α1 of the incident light changes.

[0040] pass Figure 3 It can be seen that when linearly polarized light is incident on the corner cube prism, the outgoing light in most cases is not linearly polarized light. When the Jones component phase difference of the outgoing light is 0, the corresponding incident light polarization azimuth α1 is approximately -163.94° and 16.06° (phase difference π), indicating the same beam of linearly polarized light, that is, only when the incident light is incident in this special polarization direction, the outgoing light is still linearly polarized light; when the incident light polarization azimuth α1 is -163.94° and 16.06° respectively, the corresponding outgoing light polarization azimuth α2 is approximately 43.94°, indicating that the angle between the outgoing linearly polarized light vector and the x-axis of the coordinate system is approximately 43.94°.

[0041] like Figure 4 As shown, assuming that the light entering the corner cube prism is linearly polarized light with a phase difference of zero, the reflection order of the incident light on the three reflection surfaces in the corner cube prism is BAC, and when the phase difference of the Jones component of the light emitted from the CAB area is 0, the corresponding polarization azimuth α1 of the incident light is approximately -133.94° and 46.06° (phase difference π). When the polarization azimuth α1 of the incident light is -133.94° and 46.06° respectively, the emitted light is still linearly polarized light, and the corresponding polarization azimuth α2 of the emitted light is approximately 73.94°.

[0042] Thus, the incident light polarization azimuth α1 and the outgoing light polarization azimuth α2 corresponding to the outgoing light being linearly polarized light under six different reflection orders can be simulated and calculated, as shown in Table 1 below. Under different reflection orders, only when linearly polarized light with certain special polarization azimuths is incident on the angle cone prism, the outgoing light is still linearly polarized light, and the polarization azimuth of the outgoing light is different from that of the incident light.

[0043] Table 1 α1 and α2 corresponding to the output light still being linearly polarized light

[0044]

[0045]

[0046] An orthogonal polarization output cavity dumping laser based on a corner cube prism, characterized in that the laser comprises a pump source 1, a first polarizer 2, a second polarizer 3, a Ho:YLF crystal 4, an RTP crystal 5, a third polarizer 6, a first half-wave plate 7, a first corner cube prism 8, a first right-angle prism 9, a second corner cube prism 10, a second right-angle prism 11 and a second half-wave plate 12;

[0047] The first polarizer 2 is a pump light injection mirror, and the second polarizer 3 and the third polarizer 6 are output mirrors for vertically polarized pulse light and horizontally polarized pulse light, respectively;

[0048] The RTP crystal 5 acts as an electro-optical Q switch to achieve cavity emptying laser output;

[0049] The first corner cube 8, the first right-angle prism 9, the second corner cube prism 10 and the second right-angle prism 11 form a ring resonant cavity, and the first corner cube prism 8 and the second corner cube prism 10 are arranged in the same manner and are both on the same side of the optical axis, and the first right-angle prism 9 and the second right-angle prism 11 are adjacent to each other and are both on the same side of the optical axis.

[0050] The first polarizer 2 and the third polarizer 6 have high reflection for 1.94 μm pump light, high reflection for 2.05 μm horizontal polarized light, and high transmission for 2.05 μm vertical polarized light, and the second polarizer 3 has high reflection for 1.94 μm pump light, high reflection for 2.05 μm vertical polarized light, and high transmission for 2.05 μm horizontal polarized light.

[0051] The RTP crystal 5 has a length and a width of 2 mm to 20 mm, a thickness of 2 mm to 50 mm, and a light-transmitting surface coated with a 2.05 μm high-transmittance film.

[0052] The incident surface diameters of the first corner cube prism 8 and the second corner cube prism 10 are both 20 mm-2000 mm, the incident surfaces are coated with 1.9 μm-2.1 μm high-transmittance films, the curvature radius of the reflective surface is 0-2000 mm, and the material is JGS3.

[0053] The diameters of the first half-wave plate 7 and the second half-wave plate 12 are both 8 mm to 1000 mm, and both sides are coated with 2.05 μm high-transmittance films.

[0054] The thickness of the hypotenuse of the incident surface of the first right-angle prism 9 and the second right-angle prism 11 is 5mm-1000mm, the length of the right-angle side and the hypotenuse is 5mm-1000mm, and the hypotenuse of the incident surface is coated with a 1.9μm-2.1μm high-transmittance film made of JGS3.

[0055] Implementation method:

[0056] The pump source 1 with a central wavelength of 1.94 μm is reflected by the first polarizer 2 and the second polarizer 3 and then enters the Ho:YLF crystal 4 to generate horizontally polarized oscillating light in directions a and b. The horizontally polarized oscillating light in the a direction is converted into vertically polarized oscillating light through the RTP crystal 5 to which a half-wave voltage is applied, and then is incident on the first half-wave plate 7 through the third polarizer 6. By changing the rotation angle of the first half-wave plate 7, the polarization azimuth of the linear polarized light before the incident first cone prism 8 is ensured to be 16.06°. After being incident on the first corner cone prism 8 in the reflection order ACB, it can be seen from Table 1 that the polarization azimuth of the outgoing linear polarized light becomes 43.94°. After being reflected by the first right-angle prism 9, the light beam is incident on the second corner cone prism 10 in the reflection order BCA. According to Table 1, the polarization azimuth of the outgoing light is again converted into 16.06°. After being reflected by the second right-angle prism 11, the light beam is incident on the second half-wave plate 12, and the polarization state of the outgoing light beam becomes horizontally polarized light. The horizontally polarized light passes through the polarizer 3 and enters the Ho:YLF crystal 4, and continues to oscillate in the resonant cavity along the a direction without outputting laser. That is, the linearly polarized light with a polarization azimuth angle of 16.06° is incident on the first corner cube 8 and the second corner cube 10 in the reflection order ACB and BCA, and the polarization azimuth angle of the outgoing light is still 16.06°, so the polarization-maintaining effect can be achieved.

[0057] The horizontally polarized oscillating light along the b direction generated by the Ho:YLF crystal 4 passes through the second polarizer 3 and enters the second half-wave plate 12. The polarization azimuth of the outgoing linear polarized light becomes 16.06°. After being reflected by the second right-angle prism 11, it enters the second corner cube prism 10 in the reflection order ACB. According to Table 1, the polarization azimuth of the outgoing linear polarized light becomes 43.94°. After being reflected by the first right-angle prism 9, the light beam enters the first corner cube prism 8 in the reflection order BCA. According to Table 1, the polarization azimuth of the outgoing light becomes 16.06° again. Then, it enters the first half-wave plate 7. The polarization state of the outgoing light beam becomes vertically polarized light. The vertically polarized light passes through the third polarizer 6 and becomes horizontally polarized light after passing through the RTP crystal 5. It continues to oscillate in the resonant cavity along the b direction without outputting laser. That is, the linearly polarized light with a polarization azimuth angle of 16.06° enters the corner cube prism 10 in the reflection order ACB and enters the corner cube prism 8 in the reflection order BCA in turn, and the polarization azimuth angle of the outgoing light is still 16.06°, so the polarization-maintaining effect can be achieved.

[0058] Therefore, when the RTP crystal 5 is applied with a half-wave voltage, the horizontally polarized oscillating light in the a and b directions generated by the Ho:YLF crystal 4 is constantly oscillating in the cavity, and the laser has no output until the photon density of the oscillation in the cavity reaches the maximum value, and the half-wave voltage on the RTP crystal 5 is quickly removed. At this time, the horizontally polarized oscillating light in the a direction generated by the Ho:YLF crystal 4 remains unchanged after passing through the RTP crystal 5, and then is instantly all reflected out of the cavity by the third polarizer 6 and output along the c direction; the horizontally polarized oscillating light in the b direction generated by the Ho:YLF crystal 4 is transmitted in the cavity for one cycle, and then passes through the Ho:YLF crystal 4 as vertically polarized light, which is reflected out of the cavity by the second polarizer 3, and then passes through the first polarizer 2 and is output along the d direction. Therefore, by controlling the time and width of the pressure on the RTP crystal 5, the vertically polarized giant pulse and the horizontally polarized giant pulse can be output simultaneously through the second polarizer 3 and the third polarizer 6, respectively, so that the orthogonal polarization output cavity dumping laser based on the corner cube prism can be realized.

[0059] In the above-mentioned embodiment, the rotation angle of the first half-wave plate 7 and the second half-wave plate 12 are coordinated to ensure that the polarization azimuth angle of the linear polarized light before the incident corner cube prism becomes 16.06°, 43.94°, 46.06° and 73.94° respectively, and the light passes through the first corner cube prism 8 and the second corner cube prism 10 in four different reflection orders (ACB and BCA, BCA and ACB, BAC and CAB, CAB and BAC), respectively, so that the polarization maintaining effect can be achieved, the RTP crystal 5 is applied with a half-wave voltage, the resonant cavity is in a high Q value, the laser oscillation is formed rapidly, and the laser has no output. When the oscillating photon density in the cavity reaches the maximum, the voltage on the RTP crystal 5 is removed, the resonant cavity is in a low Q value, and the cavity emptying laser output is achieved. The second polarizer 3 and the third polarizer 6 are used as output mirrors of vertically polarized light and horizontally polarized light, respectively, so as to obtain orthogonal polarization synchronous output pulse laser with high peak power, large energy and high stability.

[0060] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A cavity-dumped laser with orthogonal polarization output based on a corner cube, characterized in that: The laser comprises a pump source (1), a first polarizer (2), a second polarizer (3), a Ho:YLF crystal (4), an RTP crystal (5), a third polarizer (6), a first half-wave plate (7), a first corner cube prism (8), a first right-angle prism (9), a second corner cube prism (10), a second right-angle prism (11) and a second half-wave plate (12); The first polarizer (2) is a pump light injection mirror, and the second polarizer (3) and the third polarizer (6) are output mirrors for vertically polarized pulse light and horizontally polarized pulse light, respectively; The RTP crystal (5) acts as an electro-optical Q switch to achieve cavity emptying laser output; The first corner cube prism (8), the first right-angle prism (9), the second corner cube prism (10) and the second right-angle prism (11) form a ring resonant cavity, and the first corner cube prism (8) and the second corner cube prism (10) are arranged in the same manner and are both on the same side of the optical axis, and the first right-angle prism (9) and the second right-angle prism (11) are adjacent and are both on the same side of the optical axis; The first polarizer (2) and the third polarizer (6) have high reflection for 1.94 μm pump light, high reflection for 2.05 μm horizontal polarized light, and high transmission for 2.05 μm vertical polarized light, and the second polarizer (3) has high reflection for 1.94 μm pump light, high reflection for 2.05 μm vertical polarized light, and high transmission for 2.05 μm horizontal polarized light; The incident surface diameters of the first corner cube prism (8) and the second corner cube prism (10) are both 20 mm to 2000 mm, the incident surfaces are coated with 1.9 μm to 2.1 μm high-transmittance films, the curvature radius of the reflective surfaces is 0 to 2000 mm, and the material is JGS3; The thickness of the hypotenuse of the incident surface of the first right-angle prism (9) and the second right-angle prism (11) is 5 mm-1000 mm, the length of the right-angle side and the hypotenuse is 5 mm-1000 mm, and the hypotenuse of the incident surface is coated with a 1.9 μm-2.1 μm high-transmittance film made of JGS3; When the rotation angles of the first half-wave plate (7) and the second half-wave plate (12) are coordinated so that the polarization azimuth angles of the linear polarized light before the incident corner cube prism become 16.06°, 43.94°, 46.06° and 73.94° respectively, the emergent light and the incident light are polarized in the same state after passing through the first corner cube prism (8) and the second corner cube prism (10) in four different reflection orders, namely ACB and BCA, BCA and ACB, BAC and CAB, and CAB and BAC, thereby achieving a polarization-maintaining effect.

2. The orthogonal polarization output cavity dumping laser based on corner cube prism according to claim 1, characterized in that: The RTP crystal (5) has a length and width of 2 mm to 20 mm, a thickness of 2 mm to 50 mm, and a light-transmitting surface coated with a 2.05 μm high-transmittance film.

3. The orthogonal polarization output cavity dumping laser based on corner cube prism according to claim 1, characterized in that: The diameters of the first half-wave plate (7) and the second half-wave plate (12) are both 8 mm to 1000 mm, and both sides are coated with a 2.05 μm high-transmittance film.

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