Large-energy laser energy measuring device

Abstract

The utility model provides a macro-energy laser energy measuring device, which comprises a beam expanding lens, a polarization beam splitter and two wedge-shaped mirrors which are arranged along a light beam propagation path, the polarization beam splitter is matched with the beam expanding lens to divide an expanded light beam into two polarized light beams, and the number of the wedge-shaped mirrors is two. And the two wedge-shaped mirrors are matched with the polarization beam splitter and are used for respectively splitting the two beams of polarized light in proportion and then enabling the two beams of polarized light to enter a light measurement area. According to the utility model, the PBS, namely the polarization beam splitter, is combined with the wedge-shaped mirror, so that the change of the light splitting proportion caused by the thermal depolarization effect of the high-power laser is avoided, and the influence of the polarization state change of the high-power laser under the change of the thermal effect on the measurement is reduced, thereby improving the precision of energy measurement; the light spot area is increased through the beam expanding lens, and the damage threshold is improved; according to the utility model, as the precision of energy measurement is improved, light beams can be prevented from directly hitting on the probe of the energy meter, and after the damage threshold is improved, the damage risk of an instrument is greatly reduced, the service life of the instrument is prolonged, and the measurement cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to laser technology field especially relates to a laser energy measuring device. BACKGROUND

[0002] At present, high power pulse laser as military, industrial production, fine processing and many important tools in the measurement energy, need a long-term, stable, accurate measuring device. In the prior art, ns, hundred ps and ps pulse width high power high energy pulse laser energy measurement mode all adopt energy meter measurement or spectrometer measurement method. The former is only suitable for small energy measurement due to the low damage threshold of the detector, and large energy will damage the instrument or reduce the service life of the instrument. The latter has a large error when using a wedge-shaped mirror to directly measure the light, and the attenuation multiple is less when using a spectrometer to split the light, which cannot be well used in daily measurement process. In the process of high power amplification, the originally linearly polarized light produces thermal depolarization effect in the crystal, causing part of the energy to become elliptically polarized, and the change of polarization state will cause measurement error. The wedge-shaped mirror has different light splitting ratios for light beams with different polarization states, which is also the reason for the inaccuracy of high power beam measurement. And the traditional measurement method is to directly hit the light on the energy meter, and the service life of the energy meter (instrument is very expensive) is very short, resulting in high measurement cost. SUMMARY

[0003] In view of the above technical problems, the utility model provides a kind of high energy laser energy measuring device, to solve the problems of high power short pulse laser energy measurement error and high measurement cost in prior art.

[0004] In order to achieve the above purpose, the technical scheme of the utility model is as follows:

[0005] A kind of high energy laser energy measuring device, including the expansion lens, polarization beam splitter and wedge-shaped mirror arranged along the light beam propagation path, polarization beam splitter is used to divide the expanded light beam into two polarized light beams in cooperation with expansion lens, the wedge-shaped mirror is provided with two, two wedge-shaped mirrors are used to respectively enter the light measuring area after being divided out in proportion from two polarized light beams in cooperation with polarization beam splitter. The utility model utilizes PBS, i.e. polarization beam splitter is combined with wedge-shaped mirror, avoids the change of light splitting ratio caused by high power laser thermal depolarization effect, and reduces the influence of polarization state change of high power laser under thermal effect on measurement, thereby improving the precision of energy measurement;The spot area is increased by expansion lens, and the damage threshold is improved;The utility model improves the precision of energy measurement, can avoid that light beam directly hits energy meter probe, and after improving the damage threshold, greatly reduces the risk of instrument damage, increases the service life of instrument, and reduces the measurement cost.

[0006] Further, in order to limit the light beam propagation path, a diaphragm is further arranged along the light beam propagation path upstream of the beam expander lens for limiting the propagation path of the light beam.

[0007] Further, in order to make the incident light beam propagate along the preset light path better, the diaphragm comprises a first adjustable diaphragm and a second adjustable diaphragm arranged in sequence for the light beam to pass through in sequence.

[0008] Further, in order to change the light beam path after reflection, so that the light beam propagates in the shell, a reflecting mirror is further arranged between the beam expander lens and the polarization beam splitter for reflecting the expanded light beam to the polarization beam splitter.

[0009] Further, the two polarized light beams comprise S polarized light reflected by the polarization beam splitter, the wedge-shaped mirror comprises a first wedge-shaped mirror arranged on the propagation path of the S polarized light for splitting the S polarized light in proportion, and a first light measurement area is arranged downstream of the first wedge-shaped mirror, and an energy meter can be arranged in the first light measurement area for measuring a part of the light beam split by the first wedge-shaped mirror.

[0010] Further, a first absorption hopper is further arranged behind the first wedge-shaped mirror for absorbing another part of the light beam split by the first wedge-shaped mirror.

[0011] Further, in order to change the S light with a small attenuation coefficient into P light with a high attenuation coefficient to reach the measurement range of the energy meter, a half-wave plate is further arranged between the polarization beam splitter and the first wedge-shaped mirror for changing the S polarized light into secondary P polarized light.

[0012] Further, the two polarized light beams comprise P polarized light passing through the polarization beam splitter, the wedge-shaped mirror comprises a second wedge-shaped mirror arranged on the propagation path of the P polarized light for splitting the P polarized light in proportion, and a second light measurement area is arranged downstream of the second wedge-shaped mirror, and an energy meter can be arranged in the second light measurement area for measuring a part of the light beam split by the second wedge-shaped mirror.

[0013] Further, a second absorption hopper is further arranged behind the second wedge-shaped mirror for absorbing another part of the light beam split by the second wedge-shaped mirror.

[0014] Further, the diaphragm, the beam expander lens, the reflecting mirror, the polarization beam splitter, the wedge-shaped mirror and the light measurement area are all arranged in the shell.

[0015] The beneficial effects of the present application are as follows:

[0016] 1. The PBS, i.e. the polarization beam splitter, is combined with the wedge-shaped mirror, which avoids the change of the light splitting ratio caused by the thermal depolarization effect of high-power laser, reduces the influence of the polarization state change of high-power laser under the thermal effect on the measurement, and improves the accuracy of energy measurement.

[0017] 2、 The utility model discloses since greatly improved the measurement precision, can avoid direct beating on energy meter probe, greatly reduce the instrument damage risk, increase the instrument service life, reduce the measurement cost;

[0018] 3、 The utility model discloses the feature of the wedge mirror to different polarization state laser reflectivity is not the same to improve the light splitting multiple, make energy measuring device's measurement upper limit greatly improve;

[0019] 4、 The utility model discloses simple structure, low in cost, and not easy to damage, compared with the energy meter probe of more expensive and short service life, the utility model has reduced the cost of high -power laser energy measurement. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will be to the embodiment or prior art description needed to use the drawing briefly introduced, obviously, the following description in the drawing is only some embodiments of the utility model, for those skilled in the art, under the premise of not paying creative labor, can also obtain other drawings according to these drawings.

[0021] Figure 1 It is the structural schematic diagram of the utility model.

[0022] In the drawing: 1, first adjustable diaphragm, 2, second adjustable diaphragm, 3, beam expander, 4, reflector, 5, polarization beam splitter, 6, half wave plate, 7, first wedge mirror, 8, first absorption hopper, 9, second wedge mirror, 10, second light measurement area, 11, second absorption hopper, 12, first light measurement area. DETAILED DESCRIPTION

[0023] The technical scheme in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model, obviously, the described embodiment is only a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment in the utility model, all other embodiments obtained by those skilled in the art without paying creative labor belong to the scope of protection of the utility model.

[0024] As Figure 1As shown, the energy measuring device for high-energy laser of the embodiment 1 comprises an optical stop, a beam expander 3, a polarizing beam splitter 5 (i.e. PBS) and a wedge-shaped mirror arranged along the light beam propagation path. The high-power laser beam passes through the optical stop and the beam expander 3 in sequence and propagates to the polarizing beam splitter 5. The optical stop is used to limit the propagation path of the high-power laser beam, the beam expander is used to expand the spot area of the light beam passing through the optical stop, and the polarizing beam splitter 5 cooperates with the beam expander 3 to divide the expanded light beam into two polarized light beams. The wedge-shaped mirror is provided with two wedge-shaped mirrors, and the two wedge-shaped mirrors cooperate with the polarizing beam splitter 5 to respectively divide the two polarized light beams in proportion. The divided part of the light enters the light measuring area, and the energy meter is placed in the light measuring area to facilitate measurement. By combining the polarizing beam splitter and the wedge-shaped mirror, the change of the light splitting ratio caused by the thermal depolarization effect of the high-power laser is avoided, and the influence of the polarization state change of the high-power laser under the thermal effect change on the measurement is reduced, thereby improving the accuracy of the energy measurement.

[0025] In the embodiment, the optical stop comprises a first adjustable optical stop 1 and a second adjustable optical stop 2 arranged in sequence, so that the light beam passes through the first adjustable optical stop 1 and the second adjustable optical stop 2 in sequence. The two adjustable optical stops are selected from the adjustable optical stops in the prior art. By using the two adjustable optical stops, the incident light beam can propagate more accurately along the preset light path, and the aperture of the optical stop can be adjusted to control the light flux entering the beam expander 3.

[0026] Embodiment 2 differs from embodiment 1 in that, as shown, Figure 1 The beam expander 3 and the polarizing beam splitter 5 are further provided with a reflecting mirror 4 for changing the propagation path of the light beam expanded by the beam expander 3. The reflecting mirror 4 reflects the expanded light beam to the polarizing beam splitter 5, so that the light beam can propagate in a limited area. In the embodiment, the propagation path of the light beam reflected by the reflecting mirror 4 is perpendicular to the path of the light beam expanded by the beam expander 3 and entering the reflecting mirror 4.

[0027] Embodiment 3 differs from embodiment 2 in that, as shown, Figure 1As shown, the two polarized lights include S polarized light reflected by the polarizing beam splitter 5, and the propagation path of the S polarized light is perpendicular to the beam path of the light entering the polarizing beam splitter 5 from the mirror 4. The wedge-shaped mirror includes a first wedge-shaped mirror 7 arranged on the propagation path of the S polarized light for splitting the S polarized light by a fixed ratio, and a first light measuring area 12 is arranged downstream of the first wedge-shaped mirror 7, and a first absorption funnel 8 is further arranged behind the first wedge-shaped mirror 7. The part of the light beam split by the first wedge-shaped mirror 7 enters the first light measuring area 12, and the rest of the S polarized light enters the first absorption funnel. In the embodiment, the propagation path of the light beam split by the first wedge-shaped mirror 7 and entering the first light measuring area 12 is perpendicular to the propagation path of the S polarized light entering the first wedge-shaped mirror 7, and the rest of the S polarized light also propagates along the propagation path of the light beam entering the first wedge-shaped mirror 7 and then enters the first absorption funnel 8. Therefore, the first absorption funnel 8 is arranged on the rear side of the first wedge-shaped mirror 7 along the original light path of the S polarized light reflected by the polarizing beam splitter 5; and the first light measuring area 12 is arranged downstream of the first wedge-shaped mirror 7 in a direction perpendicular to the light path of the S polarized light entering the first wedge-shaped mirror 7. An energy meter can be placed in the first light measuring area 12, and the light beam entering the first light measuring area 12 is measured by the energy meter placed in the first light measuring area 12 to obtain a small proportion of energy, and then the energy value of the S polarized light can be obtained according to the preset coefficient of the energy meter.

[0028] Embodiment 4 differs from Embodiment 3 in that, as shown in Figure 1 A half-wave plate 6 is further arranged between the polarizing beam splitter 5 and the first wedge-shaped mirror 7 for converting the S polarized light into secondary P polarized light, so that the S polarized light with a smaller attenuation coefficient is converted into P polarized light with a higher attenuation coefficient, thereby achieving the measurement range of the energy meter.

[0029] Embodiment 5 differs from Embodiment 4 in that, as shown in Figure 1As shown, the two polarized lights further include P-polarized light passing through the polarization beam splitter 5, and the propagation path of the P-polarized light is along the light beam path entering the polarization beam splitter 5 after coming out of the mirror 4. The wedge-shaped mirror includes a second wedge-shaped mirror 9 arranged on the propagation path of the P-polarized light for splitting the P-polarized light in proportion. A second light measurement area 10 is arranged downstream of the second wedge-shaped mirror 9, and a second absorption funnel 11 is further arranged behind the second wedge-shaped mirror 9. The partial light beam split by the second wedge-shaped mirror 9 enters the second light measurement area 10, and the rest of the P-polarized light enters the second absorption funnel 11. In the embodiment, the propagation path of the light beam entering the second light measurement area 10 after being split by the second wedge-shaped mirror 9 is perpendicular to the propagation path of the P-polarized light entering the second wedge-shaped mirror 9, and the rest of the P-polarized light further propagates along the propagation path of the light beam entering the second wedge-shaped mirror 9 and then enters the second absorption funnel 11. Therefore, the second absorption funnel 11 is arranged on the rear side of the second wedge-shaped mirror 9 along the original light path of the P-polarized light passing through the polarization beam splitter 5; and the second light measurement area 10 is arranged downstream of the second wedge-shaped mirror 9 in a direction perpendicular to the light path of the P-polarized light entering the second wedge-shaped mirror 9. An energy meter can be placed in the second light measurement area 10, and the light beam entering the second light measurement area 10 is measured by the energy meter placed in the second light measurement area 10 to obtain a small proportion of energy, and then the energy value of the P-polarized light can be obtained according to the preset coefficient of the energy meter.

[0030] Embodiment 6 differs from Embodiment 5 in that, as shown in Figure 1 The first adjustable diaphragm 1, the second adjustable diaphragm 2, the beam expander lens 3, the mirror 4, the polarization beam splitter 5, the half-wave plate 6, the first wedge-shaped mirror 7, the first light measurement area 12, the first absorption funnel 8, the second wedge-shaped mirror 9, the second light measurement area 10, and the second absorption funnel 11 are arranged in the housing according to the above-described light propagation path.

[0031] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any modification or equivalent replacement of the technical solutions described in the foregoing embodiments within the spirit and principles of the present application, or any modification or equivalent replacement of part or all of the technical features, will not cause the essence of the corresponding technical solution to deviate from the scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A large energy laser energy measuring device, characterized by, The device comprises a beam expander (3), a polarizing beam splitter (5) and two wedge prisms arranged along the path of the light beam, the polarizing beam splitter (5) is used in cooperation with the beam expander (3) to divide the expanded light beam into two polarized light beams, and the two wedge prisms are both used in cooperation with the polarizing beam splitter (5) to divide the two polarized light beams into the light measurement area in proportion.

2. The high energy laser energy measurement device of claim 1, wherein, The device further comprises a diaphragm arranged upstream of the beam expander (3) along the path of the light beam to limit the propagation path of the light beam.

3. The high energy laser energy measurement device of claim 2, wherein, The diaphragm comprises a first adjustable diaphragm (1) and a second adjustable diaphragm (2) arranged in sequence for the light beam to pass through in sequence.

4. The high-energy laser energy measuring device according to claim 2 or 3, characterized in that, The beam expander (3) and the polarizing beam splitter (5) are further provided with a mirror (4) for reflecting the expanded light beam to the polarizing beam splitter (5).

5. The high-energy laser energy measuring device according to any one of claims 1 to 3, wherein The two polarized light beams comprise S-polarized light reflected by the polarizing beam splitter (5), and the wedge prisms comprise a first wedge prism (7) arranged on the path of the S-polarized light for dividing the S-polarized light in proportion, and a first light measurement area (12) is arranged downstream of the first wedge prism (7), and an energy meter can be arranged in the first light measurement area (12) for measuring a part of the light beam divided by the first wedge prism (7).

6. The high energy laser energy measurement device of claim 5, wherein, A first absorption funnel (8) is further arranged behind the first wedge prism (7) for absorbing another part of the light beam divided by the first wedge prism (7).

7. The high energy laser energy measurement device of claim 5, wherein, A half-wave plate (6) is further arranged between the polarizing beam splitter (5) and the first wedge prism (7) for converting the S-polarized light into secondary P-polarized light.

8. The high-energy laser energy measuring device according to any one of claims 1 to 3, 6 and 7, characterized by, The two polarized light beams comprise P-polarized light passing through the polarizing beam splitter (5), and the wedge prisms comprise a second wedge prism (9) arranged on the path of the P-polarized light for dividing the P-polarized light in proportion; and a second light measurement area (10) is arranged downstream of the second wedge prism (9), and an energy meter can be arranged in the second light measurement area (10) for measuring a part of the light beam divided by the second wedge prism (9).

9. The high energy laser energy measurement device of claim 8, wherein, A second absorption funnel (11) is further arranged behind the second wedge prism (9) for absorbing another part of the light beam divided by the second wedge prism (9).

10. The high energy laser energy measurement device of claim 4, wherein, The device further comprises a housing, and the diaphragm, the beam expander (3), the mirror (4), the polarizing beam splitter (5), the wedge prisms and the light measurement area are all arranged in the housing.

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