Observation apparatus and observation method

Abstract

The present invention provides an observation device and observation method that can easily acquire complex amplitude images of an object being observed with a simple configuration, even when light scattering is strong in the object being observed. [Solution] The observation device 1 comprises a light source 11A, a polarization-dependent spatial modulation element 26, a polarization camera 29, and a processing unit 40, etc. The light source 11A outputs polarized, spatially coherent light. The polarization-dependent spatial modulation element 26 is provided on the Fourier plane with respect to the imaging surface 29a of the polarization camera 29, and receives light that has passed through the object to be observed S, spatially modulates the polarization state of the light, and outputs it. The polarization camera 29 acquires intensity images of each of the multiple polarization components on the imaging surface 29a. The processing unit 40 determines the complex amplitude distribution of light at the time of input to the polarization-dependent spatial modulation element 26 based on the intensity images of each of the multiple polarization components and the relationship between the complex amplitude distribution of light at the time of input to the polarization-dependent spatial modulation element 26 and the complex amplitude distribution of light on the imaging surface 29a.

Claims

1. An illumination unit that irradiates the object to be observed with polarized light, An imaging unit that acquires intensity images of each of multiple polarization components on the imaging surface, A polarization-dependent spatial modulation element is provided on the Fourier plane with respect to the imaging surface, receives light that has been irradiated by the illumination unit and passed through the object to be observed, spatially modulates the polarization state of the light, and outputs the modulated light to the imaging unit. A processing unit for obtaining a complex amplitude image of the object being observed, Equipped with, The aforementioned processing unit, The complex amplitude distribution of light at the time of input to the polarization-dependent spatial modulation element, and the intensity image I of the jth polarization component among the intensity images of each of the plurality of polarization components acquired by the imaging unit. ｊ The pupil function P relates the relationship between and ｊ as, After performing an initialization step to initialize the complex amplitude distribution of light in the Fourier plane, For each of the aforementioned multiple polarization components, the complex amplitude distribution of light in the Fourier plane is defined as the pupil function P. ｊ A modulation processing step that modulates based on, an inverse Fourier transform processing step that performs an inverse Fourier transform on the complex amplitude distribution of light after this modulation processing to obtain the complex amplitude distribution of light on the imaging surface, and an intensity image I that determines the amplitude of the complex amplitude distribution of light after this inverse Fourier transform processing. ｊ An amplitude constraint processing step that replaces and constrains the amplitude of the light; a Fourier transform processing step that performs a Fourier transform on the complex amplitude distribution of the light after this amplitude constraint processing to obtain the complex amplitude distribution of the light on the Fourier plane; and the complex amplitude distribution of the light and the pupil function P after this Fourier transform processing. ｊ A series of processes including an update process step, which updates the complex amplitude distribution of light in the Fourier plane based on the above, is repeated multiple times to obtain the complex amplitude distribution of light at the time of input to the polarization-dependent spatial modulation element. Based on this complex amplitude distribution, a complex amplitude image of the object being observed is obtained. Observation device.

2. An illumination unit that irradiates the object to be observed with unpolarized light, An imaging unit that acquires intensity images of each of multiple polarization components on the imaging surface, A polarization-dependent spatial modulation element is provided on the Fourier plane with respect to the imaging surface, receives light that has been irradiated by the illumination unit and passed through the object to be observed, spatially modulates the polarization state of the light, and outputs the modulated light to the imaging unit. A polarizer provided in the optical path between the object to be observed and the polarization-dependent spatial modulation element, A processing unit for obtaining a complex amplitude image of the object being observed, Equipped with, The aforementioned processing unit, The complex amplitude distribution of light at the time of input to the polarization-dependent spatial modulation element, and the intensity image I of the jth polarization component among the intensity images of each of the plurality of polarization components acquired by the imaging unit. ｊ The pupil function P relates the relationship between and ｊ as, After performing an initialization step to initialize the complex amplitude distribution of light in the Fourier plane, For each of the plurality of polarization components, a modulation processing step of modulating the complex amplitude distribution of light on the Fourier plane based on the pupil function P ｊ An inverse Fourier transform processing step of performing an inverse Fourier transform on the complex amplitude distribution of light after this modulation processing to obtain the complex amplitude distribution of light on the imaging plane, and an amplitude constraint processing step of replacing and constraining the amplitude of the complex amplitude distribution of light after this inverse Fourier transform processing with the amplitude of the intensity image I ｊ A Fourier transform processing step of performing a Fourier transform on the complex amplitude distribution of light after this amplitude constraint processing to obtain the complex amplitude distribution of light on the Fourier plane, and an update processing step of updating the complex amplitude distribution of light on the Fourier plane based on the complex amplitude distribution of light after this Fourier transform processing and the pupil function P ｊ A series of processes including the above steps are repeatedly performed a plurality of times to obtain the complex amplitude distribution of light at the time of input to the polarization-dependent spatial modulation element. Based on this complex amplitude distribution, a complex amplitude image of the object being observed is obtained. Observation device.

3. The system further comprises a quarter-wave plate provided in the optical path between the polarization-dependent spatial modulation element and the imaging unit. The observation apparatus according to claim 1 or 2.

4. The polarization-dependent spatial modulation element is provided integrated with the imaging unit. The observation apparatus according to claim 1 or 2.

5. The polarization-dependent spatial modulation element is provided at the pupil position of the objective lens located on the optical path between the object being observed and the imaging unit, and is integrated with the objective lens. The observation apparatus according to claim 1 or 2.

6. The polarization-dependent spatial modulation element spatially modulates the polarization state based on an optical vortex pattern in which the direction of the velocity axis of each pixel rotates in proportion to the deflection angle θ at a polar socket (r, θ), or a random pattern in which the direction of the velocity axis of each pixel is random. The observation apparatus according to claim 1 or 2.

7. The polarization-dependent spatial modulation element is a birefringent pattern retarder or a spatial light modulator. The observation apparatus according to claim 1 or 2.

8. The imaging unit includes a polarization camera that simultaneously acquires intensity images of each of the plurality of polarization components. The observation apparatus according to claim 1 or 2.

9. The imaging unit includes a polarization beam splitter that separates each of the plurality of polarization components from each other, and a plurality of cameras that individually acquire intensity images of each polarization component separated by the polarization beam splitter. The observation apparatus according to claim 1 or 2.

10. An illumination unit that irradiates the object to be observed with polarized light, An imaging unit that acquires intensity images of each of multiple polarization components on the imaging surface, A polarization-dependent spatial modulation element is provided on the Fourier plane with respect to the imaging surface, receives light that has been irradiated by the illumination unit and passed through the object to be observed, spatially modulates the polarization state of the light, and outputs the modulated light to the imaging unit. A method for obtaining a complex amplitude image of the object to be observed using the following: The complex amplitude distribution of light at the time of input to the polarization-dependent spatial modulation element, and the intensity image I of the jth polarization component among the intensity images of each of the plurality of polarization components acquired by the imaging unit. ｊ The pupil function P relates the relationship between and ｊ as, After performing an initialization step to initialize the complex amplitude distribution of light in the Fourier plane, For each of the aforementioned multiple polarization components, the complex amplitude distribution of light in the Fourier plane is defined as the pupil function P. ｊ A modulation processing step that modulates based on, an inverse Fourier transform processing step that performs an inverse Fourier transform on the complex amplitude distribution of light after this modulation processing to obtain the complex amplitude distribution of light on the imaging surface, and an intensity image I that determines the amplitude of the complex amplitude distribution of light after this inverse Fourier transform processing. ｊ An amplitude constraint processing step that replaces and constrains the amplitude of the light; a Fourier transform processing step that performs a Fourier transform on the complex amplitude distribution of the light after this amplitude constraint processing to obtain the complex amplitude distribution of the light on the Fourier plane; and the complex amplitude distribution of the light and the pupil function P after this Fourier transform processing. ｊ A series of processes including an update process step, which updates the complex amplitude distribution of light in the Fourier plane based on the above, is repeated multiple times to obtain the complex amplitude distribution of light at the time of input to the polarization-dependent spatial modulation element. Based on this complex amplitude distribution, a complex amplitude image of the object being observed is obtained. Observation method.

11. An illumination unit that irradiates the object to be observed with unpolarized light, An imaging unit that acquires intensity images of each of multiple polarization components on the imaging surface, A polarization-dependent spatial modulation element is provided on the Fourier plane with respect to the imaging surface, receives light that has been irradiated by the illumination unit and passed through the object to be observed, spatially modulates the polarization state of the light, and outputs the modulated light to the imaging unit. A polarizer provided in the optical path between the object to be observed and the polarization-dependent spatial modulation element, A method for obtaining a complex amplitude image of the object to be observed using the following: The complex amplitude distribution of light at the time of input to the polarization-dependent spatial modulation element, and the intensity image I of the jth polarization component among the intensity images of each of the plurality of polarization components acquired by the imaging unit. ｊ The pupil function P relates the relationship between and ｊ as, After performing an initialization step to initialize the complex amplitude distribution of light in the Fourier plane, For each of the aforementioned multiple polarization components, the complex amplitude distribution of light in the Fourier plane is defined as the pupil function P. ｊ A modulation processing step that modulates based on, an inverse Fourier transform processing step that performs an inverse Fourier transform on the complex amplitude distribution of light after this modulation processing to obtain the complex amplitude distribution of light on the imaging surface, and an intensity image I that determines the amplitude of the complex amplitude distribution of light after this inverse Fourier transform processing. ｊ An amplitude constraint processing step that replaces and constrains the amplitude of the light; a Fourier transform processing step that performs a Fourier transform on the complex amplitude distribution of the light after this amplitude constraint processing to obtain the complex amplitude distribution of the light on the Fourier plane; and the complex amplitude distribution of the light and the pupil function P after this Fourier transform processing. ｊ A series of processes including an update process step, which updates the complex amplitude distribution of light in the Fourier plane based on the above, is repeated multiple times to obtain the complex amplitude distribution of light at the time of input to the polarization-dependent spatial modulation element. Based on this complex amplitude distribution, a complex amplitude image of the object being observed is obtained. Observation method.

12. A quarter-wave plate is further provided in the optical path between the polarization-dependent spatial modulation element and the imaging unit. The observation method according to claim 10 or 11.

13. The polarization-dependent spatial modulation element is provided integrated with the imaging unit. The observation method according to claim 10 or 11.

14. The polarization-dependent spatial modulation element is provided at the pupil position of the objective lens located on the optical path between the object being observed and the imaging unit, and is integrated with the objective lens. The observation method according to claim 10 or 11.

15. The polarization-dependent spatial modulation element spatially modulates the polarization state based on an optical vortex pattern in which the direction of the velocity axis of each pixel rotates in proportion to the deflection angle θ at a polar socket (r, θ), or a random pattern in which the direction of the velocity axis of each pixel is random. The observation method according to claim 10 or 11.

16. The polarization-dependent spatial modulation element is a birefringent pattern retarder or a spatial light modulator. The observation method according to claim 10 or 11.

17. The imaging unit includes a polarization camera that simultaneously acquires intensity images of each of the plurality of polarization components. The observation method according to claim 10 or 11.

18. The imaging unit includes a polarization beam splitter that separates each of the plurality of polarization components from each other, and a plurality of cameras that individually acquire intensity images of each polarization component separated by the polarization beam splitter. The observation method according to claim 10 or 11.

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