A curved transparent object imaging system

Abstract

The present invention provides a curved transparent object imaging system, wherein a first coupler sends one path of a laser signal to an imaging device, and sends the other path to a third coupler after delay processing; the imaging device irradiates the laser signal to a position on the curved transparent object, and the laser signal is transmitted to the second coupler after passing the position on the curved transparent object; the second coupler converts one path of the laser signal it receives into an optical path electrical signal through a detector and a signal collector, and transmits the other path to the third coupler; some spectral components are coupled at the third coupler to generate an interference optical signal with the maximum light intensity; a processing device determines the detection optical path of the spectral component of the corresponding wavelength according to the moment when the optical path electrical signal is received, and determines the distance between the position on the curved transparent object and the laser signal exit point on the imaging device and the thickness at the position according to the wavelength of the spectral component corresponding to the corresponding interference electrical signal and the determined corresponding detection optical path.

Description

Technical Field

[0001] The invention belongs to the field of imaging, and in particular relates to a curved transparent object imaging system. Background Art

[0002] At present, there are three main imaging technologies: the first is to use one-dimensional diffraction devices such as prisms and gratings to diffract ultrafast lasers in one dimension, thereby performing line scanning on the sample; the second is to use a combination of gratings and virtual phase arrays to diffract ultrafast lasers in two dimensions, thereby performing surface scanning on the sample; the third is to focus the light pulses to a point and incident them on the corresponding position of the sample, thereby performing point scanning on the sample. Although the first two imaging technologies belong to ultrafast imaging technologies, they can only be used to image the appearance and contour of the sample; and although the third point scanning has a slow scanning speed, it has a certain tomographic imaging capability (using time-stretched optical coherence tomography OCT technology), which can determine the thickness information of transparent samples based on the changes in the interference free spectral range FSR, but it cannot be used to determine the appearance and contour of curved transparent samples. It can be seen that the existing imaging technology cannot simultaneously determine the appearance and thickness of curved transparent objects. Summary of the invention

[0003] The present invention provides a curved transparent object imaging system to solve the problem that the current imaging technology cannot simultaneously determine the appearance contour and thickness of the curved transparent object.

[0004] According to a first aspect of an embodiment of the present invention, there is provided a curved transparent object imaging system, comprising:

[0005] A laser generating device, used for generating a laser signal including a plurality of spectral components;

[0006] A first coupler is used to split the laser signal into two paths, one path is sent to the imaging device as a detection light, and the other path is sent to the third coupler after being delayed by a delay medium as a reference light;

[0007] The imaging device is used to irradiate the laser signal onto a position on the curved transparent object, and the laser signal is transmitted to the second coupler after passing through the position on the curved transparent object;

[0008] The second coupler is used to divide the laser signal it receives into two paths, one path is transmitted to the detector, and the other path is transmitted to the third coupler; the detector converts the laser signal it receives from the second coupler into an optical path electrical signal; the signal collector collects the optical path electrical signal and sends it to the processing device;

[0009] After the laser signal delayed by the delay medium is sent to the third coupler, part of its spectral components are coupled with the spectral components of the same wavelength in the laser signal provided by the second coupler at the third coupler to generate an interference light signal; the detector converts the interference light signal into an interference electrical signal; the signal collector collects the interference electrical signal and sends it to the processing device;

[0010] The processing device demodulates the interference spectrum density of each interference electrical signal to obtain the interference electrical signal with the maximum light intensity and its corresponding spectral component wavelength, and determines the detection optical path of the corresponding wavelength spectral component according to the time when the optical path electrical signal is received for the optical path electrical signal corresponding to each spectral component wavelength obtained;

[0011] According to the obtained wavelength of the spectral component corresponding to the interference electrical signal and the determined corresponding detection optical path, the distance between the position on the curved transparent object and the laser signal emission point on the imaging device and the thickness at the position are determined.

[0012] In an optional implementation, the output end of the laser generating device is connected to the input end of the first coupler, the first output end of the first coupler is connected to the first end of the circulator, and the second output end is connected to the first input end of the third coupler through the delay medium; the second end and the third end of the circulator are respectively connected to the input end of the imaging device and the second coupler, a curved transparent object is provided below the imaging device, the two output ends of the second coupler are respectively connected to the second input end of the third coupler and the second input end of the detector, the output end of the third coupler is connected to the first input end of the detector, and the output end of the detector is connected to the processing device through a signal collector.

[0013] In another optional implementation, the distance between the incident position of the laser signal output by the imaging device on the curved transparent object and the exit point of the laser signal on the imaging device is H, the thickness at the incident position is h, and the third optical path of the corresponding wavelength spectral component propagating in the curved transparent object is L3, the third optical path L3 = n*h, n represents the refractive index of the curved transparent object, which is related to the wavelength of the spectral component, so when the wavelength of the spectral component is constant, the refractive index n is constant, and the size of the detection optical path corresponding to the wavelength spectral component is determined by the size of the distance H and the thickness h; the processing device locally pre-stores the detection optical path set for each wavelength, and each detection optical path at the wavelength corresponds to a distance H and thickness h combination, and each distance H and thickness h combination is composed of multiple distance H and thickness h association relationships;

[0014] When the processing device determines the distance between the position on the curved transparent object and the laser signal emission point on the imaging device and the thickness at the position according to the wavelength of the spectral component corresponding to the interference electrical signal and the determined corresponding detection optical path, the processing device first determines the wavelength of the corresponding spectral component according to the interference electrical signals with the largest light intensity generated at the same position on the curved transparent object, and obtains the detection optical path of the spectral component of the wavelength determined based on the reception time of the corresponding optical path electrical signal;

[0015] Find out the distance H and thickness h combination corresponding to the acquired detection optical path at the wavelength; after finding out the distance H and thickness h combination corresponding to different wavelengths, compare the found distance H and thickness h combinations, and when there is the same distance H and thickness h correlation relationship in each distance H and thickness h combination and it is the only one, determine that the distance H and thickness h correlation relationship is the parameter required for imaging at the position on the curved transparent object.

[0016] In another optional implementation, a shifting device is further included, and the shifting device moves the curved transparent object so that the incident position of the laser signal output by the imaging device on the curved transparent object changes.

[0017] In another optional implementation, the processing device is connected to the displacement device, and after obtaining the parameters required for imaging the position of the curved transparent object, the processing device immediately controls the displacement device to move the curved transparent object.

[0018] In another optional implementation, the moving device drives the curved transparent object to translate in the left-right or front-back directions to achieve surface imaging of the curved transparent object, and the left-right and front-back directions are both perpendicular to the emission direction of the laser signal output by the imaging device; the moving device drives the curved transparent object to move in the left-right and front-back directions to achieve three-dimensional stereoscopic imaging of the curved transparent object.

[0019] In another optional implementation, the moving device drives the curved transparent object to rotate to achieve surface imaging of the curved transparent object, and the rotation plane is parallel to the emission direction of the laser signal output by the imaging device;

[0020] The moving device drives the curved transparent object to rotate and drives the curved transparent object to translate in the front-back direction to achieve three-dimensional stereoscopic imaging of the curved transparent object. The front-back direction is respectively perpendicular to the plane of rotation and the emission direction of the laser signal output by the imaging device.

[0021] In another optional implementation, the distance H reflects the appearance contour of the side of the curved transparent object facing the imaging device.

[0022] In another optional implementation, a dispersive medium is further included, and the dispersive medium is used to perform time domain stretching on the laser signal provided to the laser generating device or the interference light signal provided by the third coupler.

[0023] In another optional implementation, it further includes an optical amplifier disposed before the first coupler, the optical amplifier being used to optically amplify the laser signal transmitted to the first coupler;

[0024] It also includes a polarization controller, which is used to adjust the polarization state of the laser signal output by the curved transparent object so that the polarization states of the reference light and the detection light input to the third coupler are consistent, thereby ensuring the efficiency of the interference light signal formed at the third coupler corresponding to the interference spectrum.

[0025] The beneficial effects of the present invention are:

[0026] 1. The present invention improves the point scanning imaging method, adds a second coupler, and uses the second coupler to transmit part of the laser signal transmitted to the third coupler in the detection optical path to the processing device, so that the processing device obtains the detection optical path of each different wavelength spectral component. When different wavelength spectral components are incident on the same position, the factor that determines the length of their detection optical path is their wavelength. When incident on the same position, the distance H between the incident position of the laser signal output by the imaging device on the curved transparent object and the laser signal exit point on the imaging device and the thickness h at the incident position are constant under their detection optical paths. Therefore, the present invention establishes a wavelength , the corresponding relationship between the detection optical path and the distance H and the thickness h, so that the distance H and the thickness h at the position can be determined based on the wavelength and the detection optical path; and when the present invention determines the distance H and the thickness h at the position according to the combination of the distance H and the thickness h corresponding to the detection optical path under multiple different wavelength spectral components, they are all based on the interference light signal with the maximum light intensity, unifying the basic data standards, making the determination of the distance H and the thickness h more accurate; because the distance H reflects the appearance contour of the side of the curved transparent object facing the imaging device, and the present invention also obtains the thickness h, the present invention can also obtain the appearance contour of the side of the curved transparent object away from the imaging device;

[0027] 2. The present invention moves the curved transparent object by setting a shifting device, so that the incident position of the laser signal output by the imaging device on the curved transparent object changes, thereby realizing the imaging of the curved transparent object surface and the imaging of the appearance contour of the three-dimensional structure;

[0028] 3. After obtaining the parameters required for imaging the position of the curved transparent object, the present invention immediately controls the shifting device to move the curved transparent object through the processing device, thereby improving the conversion speed of the incident position of the laser signal on the curved transparent object;

[0029] 4. The present invention uses a dispersive medium to perform time domain stretching on the optical signal before it is input to the detector, so that the detector can directly collect the spectral information while ensuring the spectral resolution, thereby increasing the sampling rate to megahertz;

[0030] 5. The present invention is provided with an optical amplifier, which can amplify the series of light pulses output by the dispersive medium; and a polarization controller is provided, and the polarization state controller is used to adjust the polarization state of the light pulses output by the curved transparent object, so that the polarization states of the reference light and the detection light input to the third coupler are consistent, thereby ensuring the efficiency of the interference light signal formed at the third coupler corresponding to the interference spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of an embodiment of the curved transparent object imaging system of the present invention;

[0032] Figure 2 Schematic diagram of light pulses incident on a flat transparent object and a curved transparent object respectively;

[0033] Figure 3 It is a schematic structural diagram of another embodiment of the curved transparent object imaging system of the present invention. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention and to make the above-mentioned purposes, features and advantages of the embodiments of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0035] In the description of the present invention, unless otherwise specified and limited, it should be noted that the term "connection" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two elements. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0036] See also Figure 1, is a schematic diagram of the structure of an embodiment of the curved transparent object imaging system of the present invention. The system may include a laser generating device, a first coupler, an imaging device, a second coupler, a third coupler, a detector, a signal collector and a processing device, wherein the laser generating device is used to generate a laser signal including multiple spectral components, and the wavelength corresponding to each spectral component may be different. The first coupler is used to divide the series of light pulses into two paths, one of which is sent to the imaging device as a detection light, and the other is sent to the third coupler as a reference light through an adjustable delay line.

[0037] The imaging device is used to irradiate the laser signal to a position on the curved transparent object, and perform point scanning on the curved transparent object. After the laser signal passes through the position on the curved transparent object, it is transmitted to the second coupler, combined with Figure 1 As shown, in this embodiment, the laser signal reflected from the position on the curved transparent object can be transmitted to the second coupler via the imaging device and the circulator. Of course, after the laser signal is incident on the corresponding position, it can also be transmitted through the curved transparent object and then transmitted to the second coupler. The second coupler is used to divide the light pulse it receives into two paths, one path is transmitted to the detector, and the other path is transmitted to the third coupler; the detector converts the laser signal it receives from the second coupler into an optical path electrical signal; the signal collector collects the optical path electrical signal and sends it to the processing device.

[0038] After the laser signal delayed by the delay medium is sent to the third coupler, part of its spectral components are coupled with the spectral components of the same wavelength in the laser signal provided by the second coupler at the third coupler to generate an interference light signal; the detector converts the interference light signal into an interference electrical signal; the signal collector collects the interference electrical signal and sends it to the processing device.

[0039] The processing device demodulates the interference spectrum density of each interference electrical signal to obtain the interference electrical signal with the maximum light intensity and its corresponding spectral component wavelength, and determines the detection optical path of the spectral component of the corresponding wavelength according to the time when the optical path electrical signal is received for the optical path electrical signal corresponding to the obtained spectral component wavelength; determines the distance between the position on the curved transparent object and the laser signal exit point on the imaging device and the thickness at the position according to the obtained spectral component wavelength corresponding to the interference electrical signal and the determined corresponding detection optical path.

[0040] Since the density of the interference spectrum can reflect the obviousness of the interference phenomenon, the more obvious the interference is, that is, the greater the intensity of the interference light signal, the sparser the interference spectrum. Therefore, the processing device can pre-store locally the correspondence between the optical path electrical signal reception time and the detection optical path when the intensity of the interference light signal corresponding to each wavelength spectrum component is the maximum. After receiving the optical path electrical signal, it can determine the detection optical path of the corresponding wavelength spectrum component according to the time when the optical path electrical signal is received for each different wavelength optical path electrical signal.

[0041] Assume that the detection light output by the first coupler is incident on the curved transparent object, passes through the curved transparent object, and then is transmitted to the third coupler through the detection light path L1 (e.g. Figure 1 The light pulse output by the first coupler is incident to the corresponding position of the curved transparent object through the circulator and the imaging device, and after being reflected back from the position of the curved transparent object, it is transmitted to the third coupler through the imaging device, the circulator, and the second coupler). Let the optical path experienced by the laser signal output by the first coupler to be transmitted to the third coupler through the delay medium be the reference optical path L2. Since the spectral components of different wavelengths in the laser signal have different periods, for each spectral component, wavelength / speed of light=period (i.e., λ / c=T), and phase difference=2π*optical path difference / wavelength. In order to achieve the maximum light intensity in interference, it is necessary to satisfy phase difference=integer multiples of period. According to the above three formulas, it can be deduced that the maximum light intensity can only appear in interference when the optical path difference L1-L2=integer multiples / (2π*c). In other words, after the spectral components of different wavelengths are transmitted back to the third coupler from the reference optical path and the detection optical path, not all spectral components of all wavelengths can be coupled at the third coupler to generate an interference light signal with the maximum light intensity. Therefore, after the laser signal of the present invention is delayed by the delay medium and sent to the third coupler, part of its spectral components are coupled with the spectral components of the same wavelength in the laser signal provided by the second coupler at the third coupler to generate an interference light signal with the maximum intensity.

[0042] In this embodiment, Figure 2As shown, for a curved transparent object, the size of the corresponding detection optical path of different wavelength spectral components will differ due to the following two factors: the incident position of the laser signal output by the imaging device on the curved transparent object, the distance H between the laser signal exit point on the imaging device, and the third optical path L3 of the corresponding wavelength spectral component propagating in the curved transparent object, wherein the third optical path L3 = n*h, n represents the refractive index of the curved transparent object, which is related to the wavelength of the spectral component, and h represents the thickness of the incident position of the laser signal output by the imaging device on the curved transparent object. It can be seen that when the wavelength of the spectral component is constant, the refractive index n is constant, and the size of the corresponding detection optical path of the wavelength spectral component is determined by the size of the distance H and the thickness h. For this reason, the processing device of the present invention pre-stores the detection optical path set for each wavelength locally, and each detection optical path under the wavelength corresponds to a distance H and thickness h combination, and each distance H and thickness h combination is composed of multiple distance H and thickness h association relationships. When the processing device determines the distance between the position on the curved transparent object and the laser signal emission point on the imaging device and the thickness at the position according to the wavelength of the spectral component corresponding to the interference electrical signal and the determined corresponding detection optical path, it can first determine the wavelength of the corresponding spectral component according to the interference electrical signals with the largest light intensity generated for the same position on the curved transparent object, and obtain the detection optical path of the spectral component of the wavelength determined based on the receiving time of the corresponding optical path electrical signal; find out the distance H and thickness h combination corresponding to the obtained detection optical path at the wavelength; after finding out the corresponding distance H and thickness h combination at different wavelengths, compare the found distance H and thickness h combinations, and when there is the same distance H and thickness h correlation relationship in each distance H and thickness h combination and it is the only one, determine that the distance H and thickness h correlation relationship is the parameter required for imaging the position on the curved transparent object.

[0043] Since the distance H and thickness h are constant for the same position on a curved transparent object, the detection optical path corresponding to each wavelength pulse will be different as the wavelength of the incident spectral component changes. However, for this position, the detection optical path corresponding to each wavelength spectral component is also fixed. The present invention is based on the principle that when the wavelength of a spectral component is constant, the size of the detection optical path corresponding to the wavelength spectral component is determined by the size of the distance H and the thickness h. When the wavelength of the spectral component is constant and the incident position of the spectral component changes, the corresponding relationship between the distance H and the thickness h of the corresponding detection optical path may be placed in a combination corresponding to the wavelength and the detection optical path; when each spectral component is incident on the same position, the distance H and the thickness h are the same. Therefore, for the same position, under different wavelength spectral components, the same distance H and thickness h correlation relationship must exist in each distance H and thickness h combination corresponding to its detection optical path. By comparing each distance H and thickness h combination, when there is only one same distance H and thickness h correlation relationship in each distance H and thickness h combination, the distance H and thickness h at the corresponding position of the curved transparent object can be determined. The distance H reflects the appearance contour of the curved transparent object at the corresponding position. Therefore, the present invention can simultaneously detect the appearance contour and thickness of the curved transparent object.

[0044] When the laser signal is incident on the corresponding position on the curved transparent object and is reflected (not transmitted) and transmitted back to the second coupler, the connection diagram of the various components of the system of the present invention can be as follows: Figure 1 As shown, the output end of the laser generating device is connected to the input end of the first coupler, the first output end of the first coupler is connected to the first end of the circulator, and the second output end is connected to the first input end of the third coupler through the delay medium; the second end and the third end of the circulator are respectively connected to the input end of the imaging device and the second coupler, a curved transparent object is provided below the imaging device, the two output ends of the second coupler are respectively connected to the second input end of the third coupler and the second input end of the detector, the output end of the third coupler is connected to the first input end of the detector, and the output end of the detector is connected to the processing device through a signal collector.

[0045] In addition, in order to realize the three-dimensional structural appearance contour imaging of the curved transparent object, the present invention may also include a shifting device, which moves the curved transparent object so that the incident position of the laser signal output by the imaging device on the curved transparent object changes. The moving device can drive the curved transparent object to translate in the left-right or front-back direction. Since the present invention can not only obtain the appearance contour but also the thickness, when the curved transparent object is line scanned, the surface imaging of the curved transparent object can be realized, and the left-right and front-back directions are perpendicular to the emission direction of the laser signal output by the imaging device; the moving device can also drive the curved transparent object to move in the left-right and front-back directions to realize the three-dimensional stereoscopic imaging of the curved transparent object. The mobile device can also drive the curved transparent object to rotate to achieve surface imaging of the curved transparent object, and the rotation plane is parallel to the emission direction of the laser signal output by the imaging device; the mobile device can also drive the curved transparent object to rotate and drive the curved transparent object to translate in the front-back direction to achieve three-dimensional stereoscopic imaging of the curved transparent object, and the front-back direction is respectively perpendicular to the rotation plane and the emission direction of the laser signal output by the imaging device. If the mobile device drives the curved transparent object to rotate, the rotation angle needs to be combined when restoring the three-dimensional structure of the curved transparent object.

[0046] In order to increase the conversion speed of the incident position of the laser signal on the curved transparent object, the processing device of the present invention can also be connected to the shifting device, and after obtaining the parameters required for imaging the position of the curved transparent object, it can immediately control the shifting device to move the curved transparent object. In this embodiment, the laser signal can be an ultrafast pulse laser with a spectral range of more than ten nanometers and a pulse repetition frequency greater than megahertz MHz. The imaging device can include a collimator and an objective lens, the collimator collimates the laser signal provided by the circulator, and the objective lens concentrates the spectral components of different wavelengths to one point and irradiates the corresponding position of the curved transparent object; the adjustable delay medium can be an adjustable delay line, and the signal collector can be a high-speed oscilloscope.

[0047] It can be seen from the above embodiments that the present invention improves the point scanning imaging method, adds a second coupler, and uses the second coupler to transmit part of the laser signal transmitted to the third coupler in the detection light path to the processing device, so that the processing device obtains the detection light path of each different wavelength spectral component. When different wavelength spectral components are incident on the same position, the factor that determines the length of their detection light path is their wavelength. When incident on the same position, each different wavelength spectral component has a certain distance H between the incident position of the laser signal output by the imaging device on the curved transparent object and the laser signal exit point on the imaging device, as well as the thickness h at the incident position. Therefore, the present invention establishes The correspondence between the wavelength, the detection optical path, the distance H, and the thickness h is determined, so that the distance H and the thickness h at the position can be determined based on the wavelength and the detection optical path; and when the present invention determines the distance H and the thickness h at the position according to the combination of the distance H and the thickness h corresponding to the detection optical path under multiple different wavelength spectral components, it is based on the interference light signal with the maximum light intensity, unifies the basic data standards, and makes the determination of the distance H and the thickness h more accurate; because the distance H reflects the appearance contour of the side of the curved transparent object facing the imaging device, and the present invention also obtains the thickness h, the present invention can also obtain the appearance contour of the side of the curved transparent object away from the imaging device.

[0048] See also Figure 3 , is a schematic structural diagram of another embodiment of the curved transparent object imaging system of the present invention. Figure 3 and Figure 1 The difference between the illustrated embodiments is that the system may also include an optical amplifier disposed before the first coupler, the optical amplifier being used to optically amplify the laser signal transmitted to the first coupler; the system may also include a dispersive medium, the dispersive medium being used to time-domain stretch the laser signal provided to the laser generating device or the interference optical signal provided by the third coupler. In this embodiment, the dispersive medium is disposed between the laser generating device and the optical amplifier. The present invention utilizes a dispersive medium to time-domain stretch the optical signal before it is input to the detector, and while ensuring the spectral resolution, the detector can directly collect the spectral information using the detector, thereby increasing the sampling rate to megahertz.

[0049] The system may also include a polarization controller, which is used to adjust the polarization state of the laser signal output by the curved transparent object so that the polarization states of the reference light and the detection light input to the third coupler are consistent, thereby ensuring the efficiency of the interference light signal formed at the third coupler corresponding to the interference spectrum. In this embodiment, the polarization controller can be arranged between the third end of the circulator and the input end of the second coupler.

[0050] It can be seen from the above embodiments that the present invention improves the point scanning imaging method, adds a second coupler, and uses the second coupler to transmit part of the laser signal transmitted to the third coupler in the detection light path to the processing device, so that the processing device obtains the detection light path of each different wavelength spectral component. When different wavelength spectral components are incident on the same position, the factor that determines the length of their detection light path is their wavelength. When incident on the same position, each different wavelength spectral component has a certain distance H between the incident position of the laser signal output by the imaging device on the curved transparent object and the laser signal exit point on the imaging device, as well as the thickness h at the incident position. Therefore, the present invention establishes The correspondence between the wavelength, the detection optical path, the distance H, and the thickness h is determined, so that the distance H and the thickness h at the position can be determined based on the wavelength and the detection optical path; and when the present invention determines the distance H and the thickness h at the position according to the combination of the distance H and the thickness h corresponding to the detection optical path under multiple different wavelength spectral components, it is based on the interference light signal with the maximum light intensity, unifies the basic data standards, and makes the determination of the distance H and the thickness h more accurate; because the distance H reflects the appearance contour of the side of the curved transparent object facing the imaging device, and the present invention also obtains the thickness h, the present invention can also obtain the appearance contour of the side of the curved transparent object away from the imaging device.

[0051] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0052] It will be appreciated that the invention is not limited to the precise construction that has been described above and shown in the drawings and that various modifications and changes may be made without departing from its scope. The scope of the invention is governed solely by the appended claims.

Claims

1. A curved transparent object imaging system, characterized in that: include: A laser generating device, used for generating a laser signal including a plurality of spectral components; A first coupler is used to split the laser signal into two paths, one path is sent to the imaging device as a detection light, and the other path is sent to the third coupler after being delayed by a delay medium as a reference light; The imaging device is used to irradiate the laser signal onto a position on the curved transparent object, and the laser signal is transmitted to the second coupler after passing through the position on the curved transparent object; The second coupler is used to divide the laser signal it receives into two paths, one path is transmitted to the detector, and the other path is transmitted to the third coupler; the detector converts the laser signal it receives from the second coupler into an optical path electrical signal; the signal collector collects the optical path electrical signal and sends it to the processing device; After the laser signal delayed by the delay medium is sent to the third coupler, part of its spectral components are coupled with the spectral components of the same wavelength in the laser signal provided by the second coupler at the third coupler to generate an interference light signal; the detector converts the interference light signal into an interference electrical signal; the signal collector collects the interference electrical signal and sends it to the processing device; The processing device demodulates the interference spectrum density of each interference electrical signal to obtain the interference electrical signal with the maximum light intensity and its corresponding spectral component wavelength, and determines the detection optical path of the corresponding wavelength spectral component according to the time when the optical path electrical signal is received for the optical path electrical signal corresponding to each spectral component wavelength obtained; Determine the distance between the position on the curved transparent object and the laser signal emission point on the imaging device and the thickness at the position according to the obtained wavelength of the spectral component corresponding to the interference electrical signal and the determined corresponding detection optical path; The output end of the laser generating device is connected to the input end of the first coupler, the first output end of the first coupler is connected to the first end of the circulator, and the second output end is connected to the first input end of the third coupler through the delay medium; the second end and the third end of the circulator are respectively connected to the input end of the imaging device and the second coupler, a curved transparent object is provided below the imaging device, the two output ends of the second coupler are respectively connected to the second input end of the third coupler and the second input end of the detector, the output end of the third coupler is connected to the first input end of the detector, and the output end of the detector is connected to the processing device through the signal collector; It also includes a shifting device, which moves the curved transparent object so that the incident position of the laser signal output by the imaging device on the curved transparent object changes; The shifting device drives the curved transparent object to translate in the left-right or front-back directions to achieve surface imaging of the curved transparent object, and the left-right and front-back directions are both perpendicular to the emission direction of the laser signal output by the imaging device; the shifting device drives the curved transparent object to move in the left-right and front-back directions to achieve three-dimensional stereoscopic imaging of the curved transparent object.

2. The curved transparent object imaging system according to claim 1, characterized in that: Assume that the distance between the incident position of the laser signal output by the imaging device on the curved transparent object and the exit point of the laser signal on the imaging device is H, and the thickness at the incident position is h. Assume that the third optical path of the corresponding wavelength spectral component propagating in the curved transparent object is L3, and the third optical path L3=n*h, where n represents the refractive index of the curved transparent object, which is related to the wavelength of the spectral component. Therefore, when the wavelength of the spectral component is constant, the refractive index n is constant, and the size of the detection optical path corresponding to the wavelength spectral component is determined by the size of the distance H and the thickness h; the processing device locally pre-stores the detection optical path set for each wavelength, and each detection optical path under the wavelength corresponds to a distance H and thickness h combination, and each distance H and thickness h combination is composed of multiple distance H and thickness h association relationships; When the processing device determines the distance between the position on the curved transparent object and the laser signal emission point on the imaging device and the thickness at the position according to the wavelength of the spectral component corresponding to the interference electrical signal and the determined corresponding detection optical path, the processing device first determines the wavelength of the corresponding spectral component according to the interference electrical signals with the largest light intensity generated at the same position on the curved transparent object, and obtains the detection optical path of the spectral component of the wavelength determined based on the reception time of the corresponding optical path electrical signal; Find out the distance H and thickness h combination corresponding to the acquired detection optical path at the wavelength; after finding out the distance H and thickness h combination corresponding to different wavelengths, compare the found distance H and thickness h combinations, and when there is the same distance H and thickness h correlation relationship in each distance H and thickness h combination and it is the only one, determine that the distance H and thickness h correlation relationship is the parameter required for imaging at the position on the curved transparent object.

3. The curved transparent object imaging system according to claim 1, characterized in that: The processing device is connected to the displacement device, and after obtaining the parameters required for imaging the position of the curved transparent object, the processing device immediately controls the displacement device to move the curved transparent object.

4. The curved transparent object imaging system according to claim 1 or 3, characterized in that: The shifting device drives the curved transparent object to rotate, so as to realize the surface imaging of the curved transparent object, and the rotation plane is parallel to the emission direction of the laser signal output by the imaging device; The shifting device drives the curved transparent object to rotate and drives the curved transparent object to translate in the front-to-back direction to achieve three-dimensional imaging of the curved transparent object. The front-to-back direction is respectively perpendicular to the plane of rotation and the emission direction of the laser signal output by the imaging device.

5. The curved transparent object imaging system according to claim 1, characterized in that: The distance H reflects the appearance contour of the curved transparent object facing the imaging device.

6. The curved transparent object imaging system according to claim 1, characterized in that: It also includes a dispersive medium, which is used to perform time domain stretching on the laser signal provided by the laser generating device or the interference light signal provided by the third coupler.

7. The curved transparent object imaging system according to claim 1, characterized in that: It also includes an optical amplifier disposed before the first coupler, the optical amplifier being used to optically amplify the laser signal transmitted to the first coupler; It also includes a polarization controller, which is used to adjust the polarization state of the laser signal output by the curved transparent object so that the polarization states of the reference light and the detection light input to the third coupler are consistent, thereby ensuring the efficiency of the interference light signal formed at the third coupler corresponding to the interference spectrum.

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