Light source system

Abstract

The utility model provides a light source system comprising a light modulation unit used for modulating initial light to form modulated light with different optical characteristics; and the light modulation unit is used for switching modulation light with different optical characteristics at different moments. The light source system can switch and emit modulated light with different optical characteristics at different times.

Description

Technical Field

[0001] The utility model relates to the technical field of optics, and particularly relates to a light source system. Background Art

[0002] A light source system is a system used to provide light beams for applications.

[0003] For example, in the semiconductor manufacturing industry, defects generated during the production process are the main reasons for reducing the reliability and manufacturing yield of chips. Therefore, defect detection of chips is of great significance in the semiconductor manufacturing process. In semiconductor inspection equipment, it is often necessary to detect various types of defects on the object to be measured, and a light source system is required to provide light beams during the detection of various types of defects on the object to be measured. Summary of the Utility Model

[0004] The purpose of the embodiments of the present disclosure is to provide a light source system for generating light beams with different optical characteristics to meet application needs.

[0005] The utility model provides a light source system, including: a light modulation unit, which is used to modulate the initial light to form modulated light with different optical characteristics; the light modulation unit is used to switch the modulated light with different optical characteristics at different times.

[0006] Optionally, the optical characteristics include one or a combination of more of: polarization direction, propagation direction, spot size, spot shape, position, or wavelength.

[0007] Optionally, it further includes: a beam splitter, which is used to receive the modulated light and form detection light, and the beam splitter is used to make the modulated light with different optical characteristics transmit along different optical paths to form the detection light.

[0008] Optionally, the spot of the modulated light with the first optical characteristic on the surface of the beam splitter is a dot-shaped spot; the spot of the modulated light with the second optical characteristic on the surface of the beam splitter is an annular spot; the beam splitter includes a first region and a second region, the first region is used to receive the dot-shaped spot, the second region is used to receive the annular spot, and the modulated light passing through the first region and the second region propagates in different directions to form the detection light.

[0009] Optionally, the beam splitter is a first reflector, and one of the first region and the second region is a light-transmitting region and the other is a light-reflecting region; the optical modulation unit emits first modulated light with a first optical state in a first modulation state, and the optical modulation unit emits second modulated light with a second optical characteristic in a second modulation state; the light-transmitting region receives the first modulated light and transmits first detection light, and the light-reflecting region receives the second modulated light and reflects second detection light; or, the light-transmitting region receives the second modulated light and transmits second detection light, and the light-reflecting region receives the first modulated light and reflects first detection light.

[0010] Optionally, when the light-transmitting region receives the first modulated light, the light-reflecting region surrounds the light-transmitting region; when the light-reflecting region receives the first modulated light, the light-transmitting region surrounds the light-reflecting region.

[0011] Optionally, in the first modulation state, the optical modulation unit is configured to make the polarization directions at multiple positions in the cross-section of the modulated light different, and the polarization directions at multiple positions are respectively parallel to the radial direction of the cross-section of the modulated light; in the second modulation state, the optical modulation unit is configured to make the polarization directions at multiple positions in the cross-section of the modulated light different and perpendicular to the radial direction of the cross-section of the modulated light; wherein, the radial direction is the direction emitted from the central axis of the modulated light to the outside of the cross-section of the modulated light.

[0012] Optionally, the optical modulation unit includes: a polarization component, the polarization component emits the modulated light in a first modulation state with different polarization directions at multiple positions in its cross-section and respectively parallel to the radial direction of the cross-section of the modulated light; the polarization component emits the modulated light in a second modulation state with different polarization directions at multiple positions in its cross-section and perpendicular to the radial direction of the cross-section of the modulated light; a focusing component, configured to receive the modulated light passing through the polarization component and make the spot of the modulated light incident on the beam splitter be a dot-shaped spot or an annular spot.

[0013] Optionally, the polarization component includes: a first component, including a plurality of polarizers, the plurality of polarizers are arranged circumferentially around the light-emitting direction of the first component, the polarization directions of the plurality of polarizers are different and are all parallel or all perpendicular to the radial direction of the cross-section of the light emitted by the first component; and a second component, including a plurality of first modulators, the plurality of first modulators are arranged circumferentially around the light-emitting direction of the second component, the plurality of first modulators correspond to the plurality of polarizers one by one, and the polarization direction of the modulated light emitted by the first modulator rotates 90° in the second modulation state compared with the first modulation state.

[0014] Optionally, the polarization component includes: a tunable polarizer, the angle between the polarization direction in the first modulation state and the polarization direction in the second modulation state of the tunable polarizer being 90°; and a second component including a plurality of first modulators, the plurality of first modulators being circumferentially arranged around the light output direction of the second component, the polarization directions of the modulated light emitted by the plurality of first modulators rotating different preset angles relative to the polarization direction of the tunable polarizer, so that the polarization directions at multiple positions on the cross section of the modulated light emitted by the first modulator rotate 90° in the second modulation state compared to the first modulation state.

[0015] Optionally, the angle between the optical axis direction of the first modulator in the second component and the polarization direction of the corresponding polarizer in the first component is 45°.

[0016] Optionally, the angle between the optical axis direction of the first modulator in the second component and the polarization direction of the tunable polarizer is equal to half of the angle between the polarization direction of the tunable polarizer and the preset direction; the preset direction is the radial direction or the tangential direction, and the tangential direction is perpendicular to the radial direction.

[0017] Optionally, the first modulator in the second component includes an electro-optic crystal, the electro-optic crystal causing a phase delay of π for the light passing through the electro-optic crystal when a half-wave voltage is applied, and the electro-optic crystal not causing a phase delay when no voltage is applied; the angle between the optical axis of the electro-optic crystal of each first modulator and the polarization direction of the corresponding polarizer is 45 degrees when a voltage is applied.

[0018] Optionally, the first modulator in the second component includes an electro-optic crystal or a half-wave plate.

[0019] Optionally, the numerical aperture of the focusing component is greater than or equal to 0.65.

[0020] Optionally, it further includes: a first collimating mirror and a first focusing mirror arranged in sequence in the first transmission optical path on the side of the beam splitter away from the light modulation unit; and a second collimating mirror and a second focusing mirror arranged in sequence in the second transmission optical path on the side of the beam splitter away from the light modulation unit; the numerical aperture of the first collimating mirror is less than or equal to 0.75, the numerical aperture of the first focusing mirror is less than or equal to 0.75; the numerical aperture of the second collimating mirror is less than or equal to 0.75; the numerical aperture of the second focusing mirror is less than or equal to 0.75; or, the numerical aperture of the second focusing mirror is greater than or equal to 0.7.

[0021] Optionally, it further includes: a compensating mirror for changing the cross-section of the light emitted from the second region into a spot light; the light emitted from the second region passes through a first transmission optical path; the compensating mirror is located in the first transmission optical path; or, the light emitted from the second region passes through a second transmission optical path; the compensating mirror is located in the second transmission optical path.

[0022] Optionally, the optical modulation unit includes an acousto-optic modulator, and the optical modulation unit is used for modulating the emission direction of the modulated light; the beam splitter is a mirror with multiple reflecting surfaces; the modulated light with different emission directions is used for irradiating different reflecting surfaces of the mirror with multiple reflecting surfaces.

[0023] Optionally, it further includes: an unpolarized light source for emitting unpolarized light to the optical modulation unit.

[0024] In the light source system provided by the technical solution of the present invention, the optical modulation unit is used for modulating the initial light to form modulated light with different optical characteristics; the optical modulation unit is used for switching the modulated light with different optical characteristics at different times, and the light source system can switch and emit modulated light with different optical characteristics at different times to meet the application requirements.

[0025] Furthermore, the optical modulation unit is used for switching the modulated light with different optical characteristics at different times, which can ensure that there is no loss of the modulated light switched and emitted at different times, improve the light utilization rate, and prevent the light with different optical characteristics from interfering with each other. Description of the Drawings

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is a block diagram of the light source system provided by an embodiment of the present invention;

[0028] Figure 2 It is a block diagram of the optical modulation unit provided by an embodiment of the present invention;

[0029] Figure 3 It is a block diagram of the polarization component provided by an embodiment of the present invention;

[0030] Figure 4 It is an optical path diagram of the light source system provided by an embodiment of the present invention;

[0031] Figure 5Schematic diagram of the first component provided by an embodiment of the present utility model;

[0032] Figure 6 Schematic diagram of the second component provided by an embodiment of the present utility model;

[0033] Figure 7 Schematic diagram of the modulated light emitted by the optical modulation unit provided by an embodiment of the present utility model under one optical characteristic;

[0034] Figure 8 Schematic diagram of the modulated light emitted by the optical modulation unit provided by an embodiment of the present utility model under another optical characteristic;

[0035] Figure 9 Block diagram of the polarization component provided by another embodiment of the present utility model;

[0036] Figure 10 Schematic diagram of a polarization direction of the tunable polarizer provided by an embodiment of the present utility model;

[0037] Figure 11 Schematic diagram of a polarization direction of the tunable polarizer provided by an embodiment of the present utility model;

[0038] Figure 12 Schematic diagram of the second component provided by another embodiment of the present utility model;

[0039] Figure 13 Schematic diagram of the compensating mirror provided by another embodiment of the present utility model;

[0040] Figure 14 Optical path diagram of the light source system provided by another embodiment of the present utility model. Detailed implementation manners

[0041] Next, the technical solutions of the present utility model will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0042] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0043] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0044] In addition, the technical features involved in different embodiments of the present utility model described below can be combined with each other as long as they do not conflict with each other.

[0045] Embodiment 1

[0046] An embodiment of the present utility model provides a light source system 10. Refer to Figure 1 , including:

[0047] A light modulation unit 100, which is used to modulate the initial light to form modulated light with different optical characteristics; the light modulation unit 100 is used to switch the modulated light with different optical characteristics at different times.

[0048] In the detection method of this embodiment, the light source system can switch to emit modulated light with different optical characteristics at different times to meet the application requirements.

[0049] Secondly, it can ensure that the modulated light emitted by switching at different times has no loss, improve the light utilization rate, and prevent the light with different optical characteristics from interfering with each other.

[0050] The optical characteristics include one or a combination of more of: polarization direction, propagation direction, spot size, spot shape, position, or wavelength.

[0051] In one embodiment, the light source system 10 further includes: a beam splitter 200, which is used to receive the modulated light and form detection light, and the beam splitter is used to make the modulated light with different optical characteristics transmit along different optical paths to form the detection light.

[0052] In one embodiment, the detection light of different optical paths is used to be incident on the surface of the object to be measured at different incident angles. In this way, by switching different modulation states of the optical modulation unit 100, detection light with different incident angles can be obtained, and the detection light with different incident angles is used to detect different types of defects. Since it is not necessary to move the components in the light source system to obtain detection light with different incident angles, the detection efficiency is improved.

[0053] In this embodiment, refer to Figure 2 , the optical modulation unit 100 includes: a polarization component 201 and a focusing component 300.

[0054] Refer to Figure 8 , the polarization direction of the modulated light emitted by the polarization component 201 in the first modulation state is different at multiple positions in its cross-section and is respectively parallel to the radial direction of the cross-section of the modulated light. Refer to Figure 7 , the polarization direction of the modulated light emitted by the polarization component 201 in the second modulation state is different at multiple positions in its cross-section and is perpendicular to the radial direction of the cross-section of the modulated light.

[0055] The focusing component 300 is configured to receive the modulated light passing through the polarization component 201 and make the spot of the modulated light incident on the beam splitter 200 be a dot-shaped spot or an annular spot. In the first modulation state, the focusing component 300 is configured to receive the modulated light passing through the polarization component 201 and make the spot of the modulated light incident on the beam splitter 200 be a dot-shaped spot. In the second modulation state, the focusing component 300 is configured to receive the modulated light passing through the polarization component 201 and make the spot of the modulated light incident on the beam splitter 200 be an annular spot. The focusing component 300 includes one or more focusing lenses.

[0056] In one embodiment, refer to Figure 3 , the polarization component 201 includes a first component 1010 and a second component 1020.

[0057] In one embodiment, refer to Figure 5 , the first component 1010 includes a plurality of polarizers 101, and the plurality of polarizers 101 are arranged circumferentially around the light-emitting direction of the first component 1010. The polarization directions of the plurality of polarizers 101 are different and are all parallel or all perpendicular to the radial direction of the cross-section of the light emitted by the first component 1010. Figure 5 Taking the polarization directions of the plurality of polarizers 101 being different and all parallel to the radial direction of the cross-section of the light emitted by the first component 1010 as an example. In another embodiment, the polarization directions of the plurality of polarizers 101 are different and all perpendicular to the radial direction of the cross-section of the light emitted by the first component 1010.

[0058] In one embodiment, referring to Figure 6 , the second component 1020 includes a plurality of first modulators 102. The plurality of first modulators 102 are circumferentially arranged around the light-emitting direction of the second component 1020, and the plurality of first modulators 102 correspond one-to-one with a plurality of polarizers 101. The number of the first modulators 102 is the same as the number of the polarizers. The plurality of first modulators 102 corresponding one-to-one with the plurality of polarizers 101 means that the light emitted from one polarizer 101 irradiates one first modulator 102. The light emitted from different polarizers 101 irradiates different first modulators 102. The polarization direction of the modulated light emitted by the first modulator 102 rotates 90° in the second modulation state compared to the first modulation state.

[0059] In one embodiment, the polarization directions of the plurality of polarizers 101 in the first component 1010 are not adjustable, and the second component 1020 is configured to modulate the light beam irradiated from the first component 1010 to the second component 1020 so that the polarization direction of the light emitted from the second component 1020 rotates 90° in the second modulation state compared to the first modulation state.

[0060] Figure 5 In , the first component 1010 is composed of 8 polarizers 101. In other embodiments, the first component 1010 may be composed of 6 polarizers 101. In other embodiments, the first component 1010 may be composed of more than 6 polarizers 101. In other embodiments, the first component 1010 may be composed of 4 polarizers 101. The number of the polarizers 101 in the first component 1010 may also be odd.

[0061] Figure 6 In , the second component 1020 is composed of 8 first modulators 102. In other embodiments, the second component 1020 may be composed of 6 first modulators 102. In other embodiments, the second component 1020 may be composed of more than 6 first modulators 102. In other embodiments, the second component 1020 may be composed of 4 first modulators 102. The number of the first modulators 102 in the second component 1020 may also be odd.

[0062] The included angle between the optical axis direction of the first modulator 102 in the second component 1020 and the polarization direction of the corresponding polarizer 101 in the first component 1010 is 45°.

[0063] In one embodiment, the polarization directions of the plurality of polarizers 101 (referring to Figure 5The arrow directions in [ ] are different and are all parallel to the radial direction of the cross-section of the light emitted by the first component 1010. In the first modulation state, the polarization direction of the modulated light emitted by the second component 1020 is consistent with the polarization direction of the light beam emitted by the first component 1010. In the second modulation state, the included angle between the optical axis direction R1 of the first modulator 102 in the second component 1020 and the polarization direction of the corresponding polarizer 101 in the first component 1010 is 45°, and the polarization direction of the modulated light emitted by the second component 1020 is perpendicular to the polarization direction of the light beam emitted by the first component 1010.

[0064] In another embodiment, the polarization directions of multiple polarizers are different and are all perpendicular to the radial direction of the cross-section of the light emitted by the first component. In the first modulation state, the included angle between the optical axis direction of the first modulator in the second component and the polarization direction of the corresponding polarizer in the first component is 45°, and the polarization direction of the modulated light emitted by the second component is perpendicular to the polarization direction of the light beam emitted by the first component; in the second modulation state, the polarization direction of the modulated light emitted by the second component is consistent with the polarization direction of the light beam emitted by the first component.

[0065] In one embodiment, the first modulator 102 in the second component 1020 includes an electro-optic crystal. When a half-wave voltage is applied to the electro-optic crystal, the light passing through the electro-optic crystal generates a phase delay of π, and when no voltage is applied to the electro-optic crystal, no phase delay is generated. Correspondingly, the polarization direction of the modulated light emitted by the second component 1020 is consistent with the polarization direction of the light beam emitted by the first component 1010. The included angle between the optical axis of the electro-optic crystal of each first modulator 102 and the polarization direction of the corresponding polarizer 101 when a voltage is applied is 45 degrees.

[0066] In another embodiment, referring to Figure 9 , the optical modulation unit 201 includes: a tunable polarizer 1030 and a second component 1020a. The included angle between the polarization direction of the tunable polarizer 1030 in the first modulation state and the polarization direction in the second modulation state is 90°.

[0067] The polarization direction of the tunable polarizer 1030 in the first modulation state (referring to Figure 10 ) and the polarization direction of the tunable polarizer 1030 in the second modulation state (referring to Figure 11 ) have an included angle of 90.

[0068] Referring to Figure 12, the second component 1020a includes a plurality of first modulators 102a. The plurality of first modulators 102a are arranged circumferentially around the light-emitting direction of the second component 1020a. The polarization directions of the modulated light emitted by the plurality of first modulators 102a rotate different preset angles relative to the polarization direction of the tunable polarizer 1030, so that the polarization directions at multiple positions of the cross-section of the modulated light emitted by the first modulator rotate 90° between the second modulation state and the first modulation state.

[0069] The included angle between the optical axis direction R2 of the first modulator 102a in the second component 1020a and the polarization direction of the tunable polarizer 1030 can be the general case of an acute angle or an obtuse angle between the optical axis direction R2 of the first modulator 102a and the preset direction.

[0070] In this embodiment, the preset directions of the respective first modulators 102a are all different from and not perpendicular to the polarization direction of the first component; in other embodiments, there is one or more first modulators 102a whose preset directions are the same as and perpendicular to the polarization direction of the first component.

[0071] Reference Figure 12 , the included angle between the optical axis direction R2 of the first modulator 102a in the second component 1020a and the polarization direction of the tunable polarizer 1030 is equal to half of the included angle between the polarization direction of the tunable polarizer 1030 and the preset direction; the preset direction is the radial direction or the tangential direction of the modulated light emitted by the second component 1020a, and the tangential direction is perpendicular to the radial direction.

[0072] The included angle between the optical axis direction R2 of the first modulator 102a in the second component 1020a and the polarization direction of the tunable polarizer 1030 can be half of the acute angle or the obtuse angle between the optical axis direction R2 of the first modulator 102a and the preset direction.

[0073] In this embodiment, the preset directions of the respective first modulators 102a are all different from and not perpendicular to the polarization direction of the first component; in other embodiments, there is one or more first modulators 102a whose preset directions are the same as and perpendicular to the polarization direction of the first component.

[0074] In one embodiment, the first modulator 102a in the second component 1020a includes an electro-optic crystal or a half-wave plate.

[0075] In one embodiment, the tunable polarizer 1030 is configured to change the polarization direction of the tunable polarizer 1030 by rotation.

[0076] Reference Figure 4 and Figure 14, taking the beam splitter 200 as the first mirror as an example. The spot of the modulated light with the first optical property on the surface of the beam splitter 200 is a dot-shaped spot; the spot of the modulated light with the second optical property on the surface of the beam splitter 200 is an annular spot. The beam splitter 200 includes a first region and a second region, the second region surrounds the first region, the first region is used to receive the dot-shaped spot, the second region is used to receive the annular spot, and the modulated light passing through the first region and the second region propagates in different directions to form the detection light. The optical modulation unit emits the first modulated light with the first optical state in the first modulation state, the spot of the first modulated light on the surface of the beam splitter 200 is a dot-shaped spot, and the optical modulation unit emits the second modulated light with the second optical property in the second modulation state, the spot of the second modulated light on the surface of the beam splitter 200 is an annular spot.

[0077] Reference Figure 4 , the optical modulation unit 100 emits the first modulated light A11 in the first modulation state, the spot of the first modulated light A11 on the surface of the beam splitter 200 is a dot-shaped spot, and the optical modulation unit 100 emits the second modulated light B11 in the second modulation state, the spot of the second modulated light B11 on the surface of the beam splitter 200 is an annular spot.

[0078] Reference Figure 14 , the optical modulation unit 100 emits the first modulated light A12 in the first modulation state, the spot of the first modulated light A12 on the surface of the beam splitter 200 is a dot-shaped spot, and the optical modulation unit 100 emits the second modulated light B12 in the second modulation state, the spot of the second modulated light B12 on the surface of the beam splitter 200 is an annular spot.

[0079] One of the first region and the second region of the beam splitter 200 is a light-transmitting region and the other is a reflecting region. Reference Figure 4 , the first region of the beam splitter is a light-transmitting region, the second region of the beam splitter is a reflecting region, the reflecting region surrounds the light-transmitting region, the light-transmitting region receives the first modulated light and transmits the first detection light, and the reflecting region receives the second modulated light and reflects the second detection light.

[0080] Reference Figure 14 , the second region of the beam splitter is a light-transmitting region, the first region of the beam splitter is a reflecting region, the light-transmitting region surrounds the reflecting region, the light-transmitting region receives the second modulated light and transmits the second detection light, and the reflecting region receives the first modulated light and reflects the first detection light.

[0081] Reference Figure 4, in the first modulation state, the light-transmitting region of the beam splitter 200 receives the first modulated light A11 and transmits the first detection light A21. In the second modulation state, the light-reflecting region of the beam splitter 200 receives the second modulated light B11 and reflects the second detection light B21. Among them, the optical paths of the first detection light A21 and the second detection light B21 are different.

[0082] Reference Figure 14 , in the first modulation state, the light-reflecting region of the beam splitter 200 receives the first modulated light A12 and reflects the first detection light A22. In the second modulation state, the light-transmitting region of the beam splitter 200 receives the second modulated light B12 and transmits the second detection light B22. Among them, the optical paths of the second detection light B22 and the first detection light A22 are different.

[0083] Reference Figure 8 , in the first modulation state, the optical modulation unit 100 is configured to make the polarization directions different at multiple positions in the cross-section of the modulated light, and the polarization directions at the multiple positions are respectively parallel to the radial direction of the cross-section of the modulated light. In the second modulation state, reference Figure 7 , the optical modulation unit is configured to make the polarization directions different at multiple positions in the cross-section of the modulated light and perpendicular to the radial direction of the cross-section of the modulated light, and the radial direction is the direction emitted from the central axis of the modulated light to the outside of the cross-section of the modulated light.

[0084] In one embodiment, reference Figure 4 , the incident angle of the first detection light A21 on the object to be measured 600 is greater than the incident angle of the second detection light B21 on the object to be measured 600. Specifically, the incident angle of the first detection light A21 on the object to be measured 600 is 90 degrees.

[0085] In one embodiment, reference Figure 14 , the incident angle of the first detection light A22 on the object to be measured 600 is less than the incident angle of the second detection light B22 on the object to be measured 600. Specifically, the incident angle of the second detection light B22 on the object to be measured 600 is 90 degrees.

[0086] Combined with reference Figure 2 、 Figure 4 And Figure 14 , the focusing component 300 is configured to receive the modulated light passing through the polarization component 201 and make the spot of the modulated light incident on the beam splitter 200 be a dot spot or an annular spot. The focusing component 300 is located between the second component 1020 and the beam splitter 200.

[0087] In one embodiment, reference Figure 4, the numerical aperture of the focusing component 300 is greater than or equal to 0.65. Since the numerical aperture of the focusing component 300 is relatively large, the smaller the spot produced on the beam splitter 200 after the focusing component 300 focuses the outgoing light of the second component 1020, so that the first detection light A21 passes through the light-transmitting area of the beam splitter 200 without irradiating on the reflection area of the beam splitter 200.

[0088] In one embodiment, referring to Figure 14 , the numerical aperture of the focusing component 300 is greater than or equal to 0.65. Since the numerical aperture of the focusing component 300 is relatively large, the smaller the spot produced on the beam splitter 200 after the focusing component 300 focuses the outgoing light of the second component 1020, so that the first modulation light A12 irradiates as much as possible on the reflection area of the beam splitter 200 without irradiating on the light-transmitting area of the beam splitter 200.

[0089] In one embodiment, the numerical aperture of the focusing component 300 is greater than or equal to 0.7.

[0090] Referring to Figure 4 and Figure 14 , the light source system further includes: a first collimating mirror 401, a second reflecting mirror 402, and a first focusing mirror 403 arranged in sequence in the first transmission optical path on the side of the beam splitter 200 away from the light modulation unit 100; and a second collimating mirror 501, a third reflecting mirror 502, and a second focusing mirror 503 arranged in sequence in the second transmission optical path on the side of the beam splitter 200 away from the light modulation unit 100.

[0091] In one embodiment, the first focusing mirror 403 is an aspherical mirror, a cylindrical mirror, or an optical diffraction element.

[0092] In one embodiment, the second focusing mirror 503 is an aspherical mirror, a cylindrical mirror, or an optical diffraction element.

[0093] The first collimating mirror 401 is located between the beam splitter 200 and the second reflecting mirror 402, and the second reflecting mirror 402 is located between the first collimating mirror 401 and the first focusing mirror 403. The second collimating mirror 501 is located between the beam splitter 200 and the third reflecting mirror 502, and the third reflecting mirror 502 is located between the second collimating mirror 501 and the second focusing mirror 503.

[0094] In one embodiment, the numerical aperture of the first collimating mirror 401 is less than or equal to 0.75, for example, less than or equal to 0.7; the numerical aperture of the first focusing mirror 403 is less than or equal to 0.75, for example, less than or equal to 0.7; the numerical aperture of the second collimating mirror 501 is less than or equal to 0.75, for example, less than or equal to 0.7; the numerical aperture of the second focusing mirror 503 is less than or equal to 0.75, for example, less than or equal to 0.7.

[0095] In one embodiment, the numerical aperture of the first condenser lens 403 is greater than or equal to 0.7; the numerical aperture of the second condenser lens 503 is greater than or equal to 0.7.

[0096] In one embodiment, referring to Figure 4 , the light source system further includes: a compensation mirror 504, and the compensation mirror 504 is configured to change the cross section of the light emitted from the second region of the beam splitter 200 into a spot light. The light emitted from the second region passes through the second transmission optical path; the compensation mirror 504 is located between the second condenser lens 503 and the beam splitter. Specifically, the compensation mirror 504 may be located between the third mirror 502 and the second condenser lens 503, or between the third mirror 502 and the second collimator 501, or between the second collimator 501 and the beam splitter 200.

[0097] In one embodiment, referring to Figure 14 , the light source system further includes: a compensation mirror (not shown), and the compensation mirror is configured to change the cross section of the light emitted from the second region of the beam splitter 200 into a spot light. The light emitted from the second region passes through the first transmission optical path. The compensation mirror is located in the first transmission optical path. The compensation mirror is located between the first condenser lens and the beam splitter. Specifically, the compensation mirror is located between the second mirror 402 and the first condenser lens 403, or between the second mirror 402 and the first collimator 401, or between the first collimator 401 and the beam splitter 200.

[0098] In one embodiment, the light emitted from the second region passes through the second transmission optical path, and the compensation mirror is located in the second transmission optical path.

[0099] In one embodiment, referring to Figure 13 , the compensation mirror includes a plurality of half-wave plates 700, and the angle between the optical axis of each half-wave plate 700 ( Figure 13 the direction of the arrow in) and the polarization direction of the light emitted from the second region of the beam splitter 200 is 45°. The plurality of half-wave plates 700 are arranged circumferentially around the direction of the light emitted from the compensation mirror, the number of the half-wave plates 700 is equal to the number of the first modulators 102, and the half-wave plates 700 and the first modulators 102 are in one-to-one correspondence.

[0100] In other embodiments, the compensation mirror may also be a mirror.

[0101] In this embodiment, referring to Figure 4 and Figure 14 , the light source system further includes: a controller 600, and the controller 600 is configured to control the modulation state of the light modulation unit 100.

[0102] In one embodiment, the controller 600 controls the modulation state of the optical modulation unit 100 by controlling the second component 1020. The first modulator is a Pockels cell. When the controller 600 applies a certain voltage to the electro-optic crystal, the first modulator can change the polarization state of the light emitted from the polarizer. When the controller 600 does not apply a voltage to the electro-optic crystal, the first modulator does not change the polarization state of the light emitted from the polarizer. The controller 600 can quickly switch the polarization direction of the modulated light by switching the voltage applied to the electro-optic crystal.

[0103] In another embodiment, the controller 600 can control the polarization direction of the tunable polarizer. When the second component 1020 includes an electro-optic crystal, the controller 600 can apply a voltage signal to the electro-optic crystal.

[0104] In this embodiment, the light source system further includes: a first shaping mirror group, which is used to shape the first detection light so that the first detection light irradiates the object to be measured 600 with a target light spot. The first shaping mirror group is located between the first collimating mirror 401 and the first focusing mirror 403. Specifically, the first shaping mirror group includes an optical amplifier. The first shaping mirror group may also include a cylindrical mirror or a diffractive optical element.

[0105] In this embodiment, the light source system further includes: a second shaping mirror group, which is used to shape the second detection light so that the second detection light irradiates the object to be measured 600 with a target light spot. The second shaping mirror group is located between the second collimating mirror 501 and the second focusing mirror 503. Specifically, the second shaping mirror group includes an optical amplifier. The second shaping mirror group may also include a cylindrical mirror or a diffractive optical element.

[0106] The light source system further includes: an unpolarized light source, which is used to emit unpolarized light to the optical modulation unit. The unpolarized light source can emit natural light.

[0107] Embodiment 2

[0108] This embodiment further provides a light source system, which is different from that in Embodiment 1 in that: the optical modulation unit includes an acousto-optic modulator, and the optical modulation unit is used to modulate the emission direction of the modulated light; the beam splitter is a mirror with multiple reflecting surfaces; the modulated light with different emission directions is used to irradiate different reflecting surfaces of the mirror with multiple reflecting surfaces.

[0109] The light source system further includes: a controller 600, which is used to control the modulation state of the optical modulation unit. When the optical modulation unit 100 includes an acousto-optic modulator, the controller 600 can quickly change the emission direction of the modulated light emitted from the acousto-optic modulator by switching the voltage applied to the acousto-optic modulator.

[0110] The light source system further includes: a first collimating mirror, a second reflecting mirror, and a first focusing mirror arranged in sequence in the first transmission optical path on the side of the beam splitter 200 away from the light modulation unit 100; and a second collimating mirror, a third reflecting mirror, and a second focusing mirror arranged in sequence in the second transmission optical path on the side of the beam splitter 200 away from the light modulation unit 100. The descriptions of the first collimating mirror, the second reflecting mirror, and the first focusing mirror refer to the foregoing embodiments, and the descriptions of the second collimating mirror, the third reflecting mirror, and the second focusing mirror refer to the foregoing embodiments.

[0111] In this embodiment, the light source system further includes: a first shaping mirror group and a second shaping mirror group. The descriptions of the first shaping mirror group and the second shaping mirror group refer to the foregoing embodiments.

[0112] The light source system further includes: an unpolarized light source for emitting unpolarized light to the light modulation unit. The unpolarized light source can emit natural light.

[0113] Embodiment 3

[0114] This embodiment provides a detection method, including: Step S1: Modulating the initial light by the light modulation unit 100 in different modulation states to form modulated light with different optical characteristics; Step S2: Receiving the modulated light by the beam splitter 200 and forming detection light.

[0115] Wherein, the detection light with different optical characteristics is transmitted along different optical paths.

[0116] Reference Figure 4 and Figure 14 , modulating the initial light by the light modulation unit 100 in different modulation states to form different modulated lights, including: emitting modulated light by the light modulation unit 100 in the first modulation state, and the light spot of the modulated light on the surface of the beam splitter 200 is a dot-shaped light spot; emitting modulated light by the light modulation unit 100 in the second modulation state, and the light spot of the modulated light on the surface of the beam splitter 200 is an annular light spot.

[0117] Reference Figure 4 and Figure 14 , receiving the modulated light by the beam splitter 200 and forming detection light, including: receiving the dot-shaped light spot through the first area of the beam splitter 200; receiving the annular light spot through the second area of the beam splitter 200; the modulated lights passing through the first area and the second area propagate in different directions to form detection light.

[0118] Reference Figure 4 and Figure 14 , the beam splitter 200 is a first reflecting mirror, and one of the first area and the second area is a light-transmitting area and the other is a reflecting area.

[0119] ReferenceFigure 4 , the optical modulation unit 100 emits different modulated lights in different modulation states, including: the optical modulation unit 100 emits a first modulated light A11 in the first modulation state, and the optical modulation unit 100 emits a second modulated light B11 in the second modulation state. The light spot of the first modulated light A11 on the surface of the beam splitter 200 is a dot-shaped light spot. The light spot of the second modulated light B11 on the surface of the beam splitter 200 is an annular light spot.

[0120] Reference Figure 14 , the optical modulation unit 100 emits different modulated lights in different modulation states, including: the optical modulation unit 100 emits a first modulated light A12 in the first modulation state, and the optical modulation unit 100 emits a second modulated light B12 in the second modulation state. The light spot of the first modulated light A12 on the surface of the beam splitter 200 is a dot-shaped light spot, and the light spot of the second modulated light B12 on the surface of the beam splitter 200 is an annular light spot.

[0121] Reference Figure 4 , the beam splitter 200 receives the modulated light and forms a detection light, including: the beam splitter 200 receives the first modulated light A11 through the light-transmitting area and transmits the first detection light A21; the beam splitter 200 receives the second modulated light through the reflection area and reflects the second detection light. The optical paths of the first detection light A21 and the second detection light B21 are different.

[0122] Reference Figure 14 , the beam splitter 200 receives the modulated light and forms a detection light, the beam splitter 200 receives the second modulated light B12 through the light-transmitting area and transmits the second detection light B22, and the beam splitter 200 receives the first modulated light A12 through the reflection area and reflects the first detection light A22. The optical paths of the second detection light B22 and the first detection light A22 are different.

[0123] The optical modulation unit 100 includes a polarization component and a focusing component. The optical modulation unit modulates the initial light in different modulation states to form modulated lights with different optical characteristics, including: modulating the initial light by adjusting the polarization component to form modulated lights with a first optical characteristic and a second optical characteristic. The polarization directions of the modulated lights emitted by the polarization component are different at multiple positions in the cross-section, and the polarization directions at multiple positions of the modulated light with the first optical characteristic are parallel to the radial direction of the cross-section of the modulated light, and the polarization directions at multiple positions of the modulated light with the second optical characteristic are perpendicular to the radial direction of the cross-section of the modulated light; the focusing component 300 receives the modulated light passing through the polarization component, and makes the light spot of the modulated light with the first optical characteristic incident on the beam splitter be a dot-shaped light spot, and the light spot of the modulated light with the second optical characteristic be an annular light spot.

[0124] In one embodiment, the numerical aperture of the focusing lens 300 is greater than or equal to 0.65. For other descriptions of the focusing lens 300, refer to Embodiment 1.

[0125] In one embodiment, the polarization component includes: a first component including a plurality of polarizers circumferentially arranged around the light output direction of the first component; and a second component including a plurality of first modulators circumferentially arranged around the light output direction of the second component, and the plurality of first modulators correspond to the plurality of polarizers one by one. Among them, modulating the initial light through the polarization component to form a modulated light having a first optical characteristic and a second optical characteristic includes: adjusting the initial light through the first component to form an initial modulated light having a plurality of polarization directions, such that the polarization directions at multiple positions in the cross-section of the initial modulated light are different, and the polarization directions at the multiple positions of the initial modulated light are parallel or perpendicular to the radial direction of the cross-section of the initial modulated light; modulating the initial modulated light through the second component, such that the modulated light emitted from the second component switches between the first optical characteristic and the second optical characteristic.

[0126] Among them, modulating the initial modulated light through the second component, such that the modulated light emitted from the second component switches between the first optical characteristic and the second optical characteristic, includes: when the polarization directions of the plurality of polarizers are different and parallel to the radial direction of the cross-section of the light output from the first component, adjusting the second component to a first modulation state, and the polarization direction of the modulated light emitted from the second component is consistent with the polarization direction of the initial modulated light, forming a modulated light having a first optical characteristic; adjusting the second component to a second modulation state, and the polarization direction of the modulated light emitted from the second component rotates 90° relative to the polarization direction of the initial modulated light, forming a modulated light having a second optical characteristic.

[0127] Alternatively, modulating the initial modulated light through the second component, such that the modulated light emitted from the second component switches between the first optical characteristic and the second optical characteristic, includes: when the polarization directions of the plurality of polarizers are different and perpendicular to the radial direction of the cross-section of the light output from the first component, adjusting the second component to a second modulation state, and the polarization direction of the modulated light emitted from the second component is consistent with the polarization direction of the initial modulated light, forming a modulated light having a second optical characteristic; adjusting the second component to a first modulation state, and the polarization direction of the modulated light emitted from the second component rotates 90° relative to the polarization direction of the initial modulated light, forming a modulated light having a first optical characteristic.

[0128] The polarization component includes a first component and a second component. The first modulator includes an electro-optic crystal. When a half-wave voltage is applied, the electro-optic crystal causes a phase delay of π for the light passing through it, and when no voltage is applied, the electro-optic crystal does not cause a phase delay. The angle between the optical axis of the electro-optic crystal of each first modulator and the polarization direction of the corresponding polarizer is 45 degrees when a voltage is applied. If the polarization directions of multiple polarizers are different and parallel to the radial direction of the cross-section of the light emitted from the first component; the first modulation state is that no voltage is applied to multiple first modulators, and the second modulation state is that a half-wave voltage is applied to multiple first modulators. If the polarization directions of multiple polarizers are different and perpendicular to the radial direction of the cross-section of the light emitted from the first component, the first modulation state is that a half-wave voltage is applied to multiple first modulators, and the second modulation state is that no voltage is applied to multiple first modulators.

[0129] In one embodiment, the polarization component includes: a tunable polarizer; and a second component including a plurality of first modulators arranged circumferentially around the light-emitting direction of the second component. Among them, the initial light is modulated by adjusting the polarization component to form modulated light with first optical characteristics and second optical characteristics, including: emitting first linearly polarized light through the tunable polarizer; modulating the first linearly polarized light through a plurality of the first modulators so that the polarization directions of the modulated light with the first optical characteristics emitted by the plurality of first modulators rotate different first preset angles relative to the polarization direction of the first linearly polarized light, and the first preset angle is twice the angle between the first linearly polarized direction and the optical axis of the first modulator; emitting second linearly polarized light through the tunable polarizer, and the polarization direction of the second linearly polarized light is perpendicular to that of the first linearly polarized light; modulating the second linearly polarized light through a plurality of the first modulators so that the polarization directions of the modulated light with the second optical characteristics emitted by the plurality of first modulators rotate different second preset angles, and the polarization directions at multiple positions of the cross-section of the modulated light emitted by the first modulator rotate 90° in the second modulation state compared to the first modulation state, and the second preset angle is twice the angle between the second linearly polarized direction and the optical axis of the first modulator.

[0130] The detection method further includes: changing the cross-section of the light emitted from the second region into a dot-like light through a compensation mirror. Other descriptions of the compensation mirror refer to Embodiment 1.

[0131] Other descriptions of the optical modulation unit 100 refer to Embodiment 1.

[0132] Other parts in the transmission optical path all refer to Embodiment 1.

[0133] Embodiment 4

[0134] This embodiment provides a detection method, including: Step S1: The optical modulation unit 100 emits modulated light with different optical characteristics in different modulation states; Step S2: The beam splitter 200 receives the modulated light and forms detection light; wherein, the modulated light with different optical characteristics is transmitted along different optical paths.

[0135] In this embodiment, the optical modulation unit 100 includes a photoacoustic modulator, and the optical modulation unit 100 is used to modulate the emission direction of the modulated light. The beam splitter 200 is a mirror with multiple reflecting surfaces.

[0136] The optical modulation unit 100 emits modulated light with different optical characteristics in different modulation states, including: the photoacoustic modulator emits modulated light with different emission directions in different modulation states.

[0137] The beam splitter 200 receives the modulated light and forms detection light, including: the mirror with multiple reflecting surfaces receives the modulated light and forms detection light, and different reflecting surfaces of the mirror with multiple reflecting surfaces are used to receive the modulated light with different emission directions.

[0138] For other parts in the transmission optical path, refer to Embodiment 2.

[0139] Obviously, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A light source system, characterized in that: include: A light modulation unit, wherein the light modulation unit is used to modulate the initial light to form modulated light with different optical characteristics; The light modulation unit is used to switch modulated light with different optical characteristics at different times; The optical properties include polarization direction; The light modulation unit comprises: a polarization component; The light modulation unit emits first modulated light having a first optical characteristic in a first modulation state, and emits second modulated light having a second optical characteristic in a second modulation state.

2. The light source system according to claim 1, characterized in that: The optical characteristics include: one or more combinations of polarization direction, propagation direction, spot size, spot shape, position or wavelength.

3. The light source system according to claim 1, characterized in that: Also includes: A beam splitter is used to receive the modulated light and form the detection light, and the beam splitter is used to make the modulated light with different optical characteristics be transmitted along different optical paths to form the detection light.

4. The light source system according to claim 3, characterized in that: The light spot of the modulated light with the first optical characteristic on the surface of the beam splitter is a point light spot; the light spot of the modulated light with the second optical characteristic on the surface of the beam splitter is an annular light spot; the beam splitter includes a first area and a second area, the first area is used to receive the point light spot, and the second area is used to receive the annular light spot, and the modulated light passing through the first area and the second area propagates in different directions to form the detection light.

5. The light source system according to claim 4, characterized in that: The beam splitter is a first reflector, wherein one of the first region and the second region is a light-transmitting region and the other is a reflective region; The light-transmitting area receives the first modulated light and transmits the first detection light, and the reflective area receives the second modulated light and reflects the second detection light; or, the light-transmitting area receives the second modulated light and transmits the second detection light, and the reflective area receives the first modulated light and reflects the first detection light; when the light-transmitting area receives the first modulated light, the reflective area surrounds the light-transmitting area; When the reflective area receives the first modulated light, the light-transmitting area surrounds the reflective area.

6. The light source system according to any one of claims 3 to 5, characterized in that: The modulated light emitted by the polarization component in the first modulation state has different polarization directions at multiple positions of its cross section and is respectively parallel to the radial direction of the cross section of the modulated light; the modulated light emitted by the polarization component in the second modulation state has different polarization directions at multiple positions of its cross section and is perpendicular to the radial direction of the cross section of the modulated light; the light modulation unit also includes: a focusing component, which is used to receive the modulated light passing through the polarization component, and makes the light spot of the modulated light incident on the beam splitter a point spot or a ring spot.

7. The light source system according to claim 1, characterized in that: The polarization component comprises: A first component includes a plurality of polarizers, wherein the plurality of polarizers are arranged circumferentially around a light emitting direction of the first component, and the polarization directions of the plurality of polarizers are different and are all parallel or perpendicular to a radial direction of a cross section of light emitting from the first component; and The second component includes a plurality of first modulators, which are arranged circumferentially around the light emitting direction of the second component, and the plurality of first modulators correspond one-to-one to the plurality of polarizers. The polarization direction of the modulated light emitted by the first modulator is rotated by 90° in the second modulation state compared with that in the first modulation state.

8. The light source system according to claim 1, characterized in that: The polarization component comprises: an adjustable polarizer, wherein the angle between the polarization direction of the adjustable polarizer in a first modulation state and the polarization direction in a second modulation state is 90°; and A second component includes a plurality of first modulators, wherein the plurality of first modulators are arranged circumferentially around a light emitting direction of the second component, and polarization directions of modulated lights emitted by the plurality of first modulators are rotated by different preset angles relative to the polarization direction of the adjustable polarizer, so that the polarization directions at a plurality of positions of a cross section of the modulated light emitted by the first modulator are rotated by 90° in the second modulation state compared with the first modulation state; The first modulator in the second component includes an electro-optical crystal or a half-wave plate; when a half-wave voltage is applied to the electro-optical crystal, the light passing through the electro-optical crystal produces a phase delay of π, and when no voltage is applied, the electro-optical crystal does not produce a phase delay; when voltage is applied, the angle between the optical axis of the electro-optical crystal of each first modulator and the polarization direction of the corresponding polarizer is 45 degrees.

9. The light source system according to claim 7, characterized in that: The angle between the optical axis direction of the first modulator in the second component and the polarization direction of the corresponding polarizer in the first component is 45°.

10. The light source system according to claim 8, characterized in that: The angle between the optical axis direction of the first modulator in the second component and the polarization direction of the adjustable polarizer is equal to half of the angle between the polarization direction of the adjustable polarizer and a preset direction; the preset direction is a radial direction or a tangential direction, and the tangential direction is perpendicular to the radial direction.

11. The light source system according to claim 7, characterized in that: The first modulator in the second component includes an electro-optical crystal, which causes a phase delay of π to the light passing through the electro-optical crystal when a half-wave voltage is applied, and does not produce a phase delay when no voltage is applied; the angle between the optical axis of the electro-optical crystal of each first modulator and the polarization direction of the corresponding polarizer when voltage is applied is 45 degrees.

12. The light source system according to claim 6, characterized in that: The numerical aperture of the focusing component is greater than or equal to 0.

65.

13. The light source system according to claim 4, characterized in that: Also includes: A compensating mirror, the compensating mirror is used to change the cross section of the light emitted from the second area into a point-shaped light; The outgoing light of the second region passes through the first transmission light path; The compensating mirror is located in the first transmission light path; Alternatively, the outgoing light from the second area passes through a second transmission light path; and the compensation mirror is located in the second transmission light path.

14. The light source system according to claim 1, characterized in that: The light modulation unit includes a photoacoustic modulator, which is used to modulate the emission direction of the modulated light; the beam splitter is a reflector with multiple reflective surfaces; the modulated light with different emission directions is used to irradiate different reflective surfaces of the reflector with multiple reflective surfaces.

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