CN108572143A - Total Polarization Measurement Microscope - Google Patents

Abstract

The invention discloses an all-polarization measurement microscope, which is characterized in that it comprises a collimator lens, a filter, an objective lens, a polarization modulation combination, an imaging mirror and a CCD camera arranged in sequence along the incident light direction, and the sample to be measured is arranged in the filter Between the sheet and the objective lens, the objective lens and the imaging lens have a magnification; wherein, the polarization modulation combination includes a first improved Savoyard polarizer, a half-wave plate, a second improved Savoy Polarizers and Polarizers. The invention adopts a static polarization modulation combination to replace a photoelectric modulation system or a rotation system, and can obtain all polarization information of a target with only one measurement.

Description

Total Polarization Measurement Microscope

technical field

The invention relates to the field of optical image processing. More specifically, the present invention relates to a fully polarimetric microscope.

Background technique

The polarization optical microscope used to measure the polarization of samples has important application value for improving the research level of biotechnology and medical clinical detection. However, at present, rotating devices or electronically controlled modulation devices are generally used in combination with microscopes. This structure has the following disadvantages:

1. Multiple measurements are required to obtain all polarization images of the target;

2. Multiple measurements are prone to measurement errors;

3. The measurement system contains sophisticated electronic control equipment, and the system is relatively complex and expensive;

4. Real-time detection of living objects or moving scenes is not possible.

Contents of the invention

It is an object of the present invention to solve at least the above-mentioned problems and to provide at least the advantages which will be described later.

Another object of the present invention is to provide a total polarization measurement microscope that can obtain all polarization information of an object with only one measurement.

In order to realize these objects and other advantages according to the present invention, a kind of full polarization measuring microscope is provided, including collimating lens, filter plate, objective lens, polarization modulation combination, imaging mirror and CCD camera arranged in sequence along the direction of incident light, to be measured The sample is arranged between the filter and the objective lens, and the objective lens and the imaging lens have a magnification;

Wherein, the polarization modulation combination includes a first improved Savoy polarizer, a half-wave plate, a second improved Savoy polarizer and a polarizer arranged in sequence along the incident light direction;

The light emitted by the light source passes through the collimating lens and becomes parallel light with an incident direction of the Z axis. The parallel light becomes narrow-band parallel light after passing through the filter and irradiates the sample to be tested. Transmitted light, the transmitted light is decomposed into two beams of equal-intensity vibrating and perpendicular to each other linearly polarized light whose incident directions are respectively the X axis and the Y axis after passing through the first improved Sava polarizer, the two beams of line After the polarized light passes through the half-wave plate with a fast axis direction of 22.5°, the polarization direction is rotated 45° clockwise, and then decomposed into the X-axis and Y-axis after passing through the second improved Savoy polarizer. After the four beams of linearly polarized light vibrating at equal intensity pass through a polarizer whose polarization direction is 22.5° to the positive direction of the X axis, the orientations of the polarization directions of the four beams of linearly polarized light are all the same, and the four beams of linearly polarized light are imaged mirror, which forms an interference image on the CCD camera.

Preferably, both the first improved Sava polarizer and the second improved Sava polarizer include a first uniaxial crystal plate of equal thickness, a second uniaxial crystal plate, and a A half-wave plate between the axial crystal plate and the second uniaxial crystal plate, the optical axes of the first uniaxial crystal plate and the second uniaxial crystal plate are on the XZ plane and at 45° to the Z axis The orientation of the optical axis of the first uniaxial crystal plate forms an angle of 45° with the positive direction of the X and Z axes respectively; the orientation of the optical axis of the second uniaxial crystal plate forms an angle of 45° with the positive direction of the X axis and the negative direction of the Z axis respectively , the optical axes of the first uniaxial crystal plate and the second uniaxial crystal plate are perpendicular to each other, and the optical axis of the half-wave plate forms an angle of 45° with the positive directions of the X and Y axes.

Preferably, the intensity of the interference image is represented by formula 1:

Wherein, the S0, S1, S2 and S3 are the Stokes components of the four beams of linearly polarized light respectively, Ω is the carrier frequency of the polarization modulation combination, λ is the wavelength of the incident light, f is the focal length of the imaging mirror, and _xi is the image The abscissa of the plane, y _i is the ordinate of the image plane.

Preferably, the objective lens is one of objective lenses with magnifications of 10X, 20X, and 40X.

Preferably, a photographic output port for optical output during microscope image collection is also included.

The present invention at least includes the following beneficial effects: the present invention uses a static polarization modulation combination instead of a photoelectric modulation system or a rotating system, and can obtain all the polarization information of the target with only one measurement, which solves the problem that the polarization information of moving targets and dynamic scenes cannot be real-time Get the problem.

Other advantages, objectives and features of the present invention will partly be embodied through the following descriptions, and partly will be understood by those skilled in the art through the research and practice of the present invention.

Description of drawings

Fig. 1 is a kind of optical path structural diagram of polarization spectrum measuring microscope of the present invention;

Fig. 2 is the optical path structure diagram of the polarization modulation combination of the present invention;

Fig. 3 is another optical path structure diagram of the polarization spectrum measuring microscope of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings, so that those skilled in the art can implement it with reference to the description.

It should be noted that the experimental methods described in the following embodiments, unless otherwise specified, are conventional methods, and the reagents and materials, if not otherwise specified, can be obtained from commercial sources; in the description of the present invention, The terms "landscape", "portrait", "top", "bottom", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", The orientation or positional relationship indicated by "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the referred device or element must have Certain orientations, constructed and operative in certain orientations, therefore are not to be construed as limitations on the invention.

As shown in Figure 1-2, the present invention provides a kind of full polarization measurement microscope, including collimating lens, filter, objective lens, polarization modulation combination, imaging mirror and CCD camera arranged in sequence along the incident light direction, the sample to be measured is arranged in Between the filter and the objective lens, the objective lens and the imaging lens have a magnification;

Wherein, the polarization modulation combination includes a first improved Sawa polarizer (MSP1), a half-wave plate (HWP), a second improved Sawa polarizer (MSP2) and a polarizer (A );

The light emitted by the light source passes through the collimating lens and becomes parallel light with an incident direction of the Z axis. The parallel light becomes narrow-band parallel light after passing through the filter and irradiates the sample to be tested. Transmitted light, the transmitted light is decomposed into two beams of equal-intensity vibrating and perpendicular to each other linearly polarized light whose incident directions are respectively the X axis and the Y axis after passing through the first improved Sava polarizer, the two beams of line After the polarized light passes through the half-wave plate with a fast axis direction of 22.5°, the polarization direction is rotated 45° clockwise, and then decomposed into the X-axis and Y-axis after passing through the second improved Savoy polarizer. After the four beams of linearly polarized light vibrating at equal intensity pass through a polarizer whose polarization direction is 22.5° to the positive direction of the X axis, the orientations of the polarization directions of the four beams of linearly polarized light are all the same, and the four beams of linearly polarized light are imaged Mirror, that is to form an interference image on the CCD camera. When the fast axis direction of the half-wave plate is 22.5°, the second improved Sava polarizer can divide the two beams of light emitted from the half-wave plate into four beams of equal intensity (eoeo , oeeo, eooe, oeoe).

Both the first improved Sava polarizer and the second improved Sava polarizer include a first uniaxial crystal plate of equal thickness, a second uniaxial crystal plate, and a and the half-wave plate between the second uniaxial crystal plate, the optical axes of the first uniaxial crystal plate and the second uniaxial crystal plate are both on the XZ plane and form an angle of 45° with the Z axis, the first The optical axis orientation of a uniaxial crystal plate forms an angle of 45° with the positive direction of the X and Z axes respectively; the optical axis orientation of the second uniaxial crystal plate forms an angle of 45° with the positive direction of the X axis and the negative direction of the Z axis respectively, and the The optical axes of the first uniaxial crystal plate and the second uniaxial crystal plate are perpendicular to each other, and the optical axis of the half-wave plate forms an angle of 45° with the positive directions of the X and Y axes. The half-wave plate has the dual functions of phase retardation and field of view expansion; ordinary light (o light) in the left plate becomes extraordinary light (e light) after passing through the half wave plate, and vice versa. This structure can expand the field of view to about ±10°, thereby ensuring that the interference fringes in the far field are still straight fringes with equal intervals. In addition, the distance between the two outgoing rays eo and oe is the transverse shear amount, which is 2Δ (Δ is the shear amount of the veneer).

The intensity of the interference image is represented by Equation 1:

Wherein, the S0, S1, S2 and S3 are the Stokes components of the four beams of linearly polarized light respectively, and Ω is the carrier frequency of any one improved Savoyard polarizer. Since the structures of the two improved Savoie polarizers are the same, therefore The carrier frequency is the same, λ is the wavelength of the incident light, f is the focal length of the imaging mirror, x _i is the abscissa at the image plane, and y _j is the ordinate at the image plane.

The polarizer must be tilted by 45°, so that the contrast of the obtained interferogram is the highest. At this time, the intensity of the interferogram is expressed by formula 2. Among the four Stokes parameters S _0~3 , it is generally considered that S ₀ is the intensity component, and S _1~3 is the polarization component. From (2), it can be seen that the spatial domain modulation coefficient of S _2~3 is only half of that of S ₁ , This will lead to the signal-to-noise ratio of the inverted S _2-3 being significantly lower than S ₁ at the same noise level, which is not conducive to the detection of all polarization information.

The objective lens is one of objective lenses with magnifications of 10X, 20X and 40X.

Also included is a photographic output port for optical output during microscope image acquisition.

As shown in Figure 3, in one embodiment, there is a certain angle between the incident light emitted by the light source LED and the reflected light reflected from the sample surface, because a certain amount of difference will occur in the polarization characteristics when the shown angle changes , so when the polarization measurement is actually performed, more comprehensive polarization characteristics can be obtained by adjusting the incident angle of the incident light several times.

Although the embodiment of the present invention has been disclosed as above, it is not limited to the use listed in the specification and implementation, it can be applied to various fields suitable for the present invention, and it can be easily understood by those skilled in the art Therefore, the invention is not limited to the specific details and examples shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims (5)

1. a kind of full polarimetry microscope, which is characterized in that include the collimation lens set gradually along incident light direction, filtering Piece, object lens, Polarization Modulation combination, imaging lens and CCD camera, sample to be tested setting the filter plate and the object lens it Between, the object lens and imaging lens have amplification factor；

Wherein, the Polarization Modulation combination includes the first modified savart polariscope, the half-wave set gradually along incident light direction Piece, the second modified savart polariscope and polarizing film；

The light that light source is sent out passes through the filter by becoming the directional light that incident direction is Z axis, the directional light after collimation lens Become narrowband directional light after wave plate to be irradiated on sample to be tested, object lens collect the transmitted light across sample to be tested, the transmitted light Resolved into after the first modified savart polariscope the two beam equal strength vibration that incident direction is respectively X-axis and Y-axis, Mutually perpendicular linearly polarized light, the two bunch polarised light pass through fast axis direction be 22.5 ° half-wave plate rear polarizer direction along Be rotated clockwise 45 °, using be broken down into after the second modified savart polariscope respectively along X-axis and Y-axis etc. Four bunch polarised lights of strength vibration, after polarization direction is the polarizing film with X-axis positive direction at 22.5 °, four bunch The polarization direction of polarised light is orientated all same, and the four bunch polarised light passes through imaging lens, i.e., forms interference pattern in CCD camera Picture.

2. polarimetry microscope as described in claim 1 complete, which is characterized in that the first modified savart polariscope and The second modified savart polariscope includes the brilliant plate of the first single shaft of equal thickness, the second uniaxial brilliant plate and is arranged described Half-wave plate between first uniaxial brilliant plate and the second uniaxial brilliant plate, the described first uniaxial brilliant plate and the second uniaxial brilliant plate Optical axis XZ planes and with Z axis angle at 45 °, the direction of optic axis of the first uniaxial brilliant plate respectively with X, the positive angle at 45 ° of Z axis； The direction of optic axis of second uniaxial brilliant plate positive, the Z axis negative sense angle at 45 ° with X-axis respectively, the described first uniaxial brilliant plate and described second The optical axis of uniaxial crystalline substance plate is orthogonal, optical axis and X, the positive angle at 45 ° of Y-axis of the half-wave plate.

3. full polarimetry microscope as described in claim 1, which is characterized in that the intensity of the interference image is by formula 1 It indicates：

Wherein, described S0, S1, S2 and S3 are respectively the Stokes components of four bunch polarised lights, and Ω is the Polarization Modulation group The carrier frequency of conjunction, λ are lambda1-wavelength, and f is the focal length of imaging lens, x_iFor abscissa, y at image planes_iFor ordinate at image planes.

4. polarimetry microscope as described in claim 1 complete, which is characterized in that the object lens be amplification factor be 10X, One kind in the object lens of 20X, 40X.

5. full polarimetry microscope as described in claim 1, which is characterized in that when further including for MIcrosope image acquisition The photography output port of optics output.