Method for super-resolution microscopic interferometric measurement based on broadband annular radially polarized light

A method for super-resolution microscopic interferometric measurement based on broadband annular radially polarized light, comprising:

• Step 1:
• designing a two-stage relay system, for generating broadband annular radially polarized light, wherein
• the two-stage relay system comprises a light source (1), a polarizer (2), a first condenser lens (4), a first standard plane mirror (5), a liquid crystal spatial light modulator (6), a second condenser lens (8), a first cube beamsplitter (9), an analyzer (10), a third condenser lens (11), and a vortex waveplate (12);
• the first condenser lens (4) and the second condenser lens (8) constitute a first-stage relay lens group (3);
• the second condenser lens (8) and the third condenser lens (11) constitute a second-stage relay lens group (7);
• the light source (1), the polarizer (2), the first-stage relay lens group (3), the first standard plane mirror (5), the first cube beamsplitter (9), and the liquid crystal spatial light modulator (6) constitute a first-stage relay system;
• the liquid crystal spatial light modulator (6), the second-stage relay lens group (7), the first cube beamsplitter (9), the analyzer (10), and the vortex waveplate (12) constitute a second-stage relay system;
• the light source (1), the polarizer (2), the first condenser lens (4), and the first standard plane mirror (5) are arranged coaxially in sequence along a first optical axis, wherein a reflective surface of the first standard plane mirror (5) forms an angle of 45° with the first optical axis;
• and
• the liquid crystal spatial light modulator (6), the second condenser lens (8), the first cube beamsplitter (9), the analyzer (10), the third condenser lens (11), and the vortex waveplate (12) are arranged coaxially in sequence along a second optical axis, wherein the first cube beamsplitter (9) is located on a reflection optical path of the first standard plane mirror (5), and the broadband annular radially polarized light emerges from the vortex waveplate (12);
• Step 2:
• building a system for super-resolution microscopic interferometric measurement based on broadband annular radially polarized light, wherein
• the system for super-resolution microscopic interferometric measurement based on broadband annular radially polarized light comprises the two-stage relay system, a fourth condenser lens (14), a fifth condenser lens (15), a second cube beamsplitter (16), a first microscopic objective lens (17), a to-be-tested sample (18), a PZT piezoelectric ceramics (19), a second microscopic objective lens (20), a second standard plane mirror (21), a tube lens (22), and an industrial CCD camera (23), wherein the to-be-tested sample (18) is arranged on the PZT piezoelectric ceramics (19);
• the fourth condenser lens (14), the fifth condenser lens (15), the second cube beamsplitter (16), the first microscopic objective lens (17), and the to-be-tested sample (18) are arranged coaxially behind the vortex waveplate (12) along the second optical axis;
• a third optical axis passes through the second cube beamsplitter (16);
• the second standard plane mirror (21), the second microscopic objective lens (20), the second cube beamsplitter (16), the tube lens (22), and the industrial CCD camera (23) are distributed in sequence along the third optical axis;
• and the third optical axis is perpendicular to the second optical axis;
• the first microscopic objective lens (17), the to-be-tested sample (18), and the PZT piezoelectric ceramics (19) constitute a test optical path, while the second microscopic objective lens (20) and the second standard plane mirror (21) constitute a reference optical path;
• and
• the fourth condenser lens (14) and the fifth condenser lens (15) constitute a Kohler illumination lens group (13);
• Step 3:
• emitting, from the light source (1), a multi-field-of-view FOV beam, wherein:
• the multi-FOV beam passes through the polarizer (2) to generate a linearly polarized light;
• the linearly polarized light passes through the first condenser lens (4) to be converged onto the first standard plane mirror (5), and is then reflected from the first standard plane mirror (5) by 90°, onto the first cube beamsplitter (9);
• first reflected light reflected from the first cube beamsplitter (9) passes through the second condenser lens (8) to the liquid crystal spatial light modulator (6), the first reflected light being linearly polarized light with a polarization direction same as a long-side direction of a liquid crystal light valve of the liquid crystal spatial light modulator (6);
• hollow annular modulation and reflection is performed, by the liquid crystal spatial light modulator (6), on the linearly polarized light incident thereto to obtain a modulated annular beam as second reflected light;
• the second reflected light passes through the second condenser lens (8) to the first cube beamsplitter (9), passes through the analyzer (10), with a polarization direction perpendicular to the polarizer (2), through the first cube beamsplitter (9), and is then converged onto the vortex waveplate (12) through the third condenser lens (11), wherein the vortex waveplate (12) performs polarization modulation on a full-FOV beam to output the broadband annular radially polarized light;
• the broadband annular radially polarized light then passes through the Kohler illumination lens group (13) to the second cube beamsplitter (16), and is split, by the second cube beamsplitter (16), into test light and reference light, wherein the test light is transmitted to the first microscopic objective lens (17) and passes through the first microscopic objective lens (17) to illuminate the to-be-tested sample (18), and third reflected light carrying surface morphology information of the to-be-tested sample (18) reflected from the to-be-tested sample (18) passes through the first microscopic objective lens (17) to the second cube beamsplitter (16), is reflected from the second cube beamsplitter (16) into the tube lens (22), and is focused, by the tube lens (22), onto the industrial CCD camera (23), and wherein the reference light is reflected to the second microscopic objective lens (20) and passes through the second microscopic objective lens (20) to illuminate the second standard plane mirror (21), and fourth reflected light carrying surface morphology information of the second standard plane mirror (21) reflected from the second standard plane mirror (21) passes through the second microscopic objective lens (20) to the second cube beamsplitter (16), transmits into the tube lens (22) through the second cube beamsplitter (16), and is focused, by the tube lens (22), onto the industrial CCD camera (23), where meanwhile the reference light and the test light interfere with each other;
• Step 4:
• controlling, using the PZT piezoelectric ceramics (19), micro-displacement of the to-be-tested sample (18) along a direction of an optical axis, and acquiring, by the industrial CCD camera (23), several phase-shifted interferograms of the to-be-tested sample (18) within a full-FOV range of the first microscopic objective lens (17);
• and
• Step 5:
• processing, using a vertical scan interference algorithm, the acquired phase-shifted interferograms to obtain 3D topography information of the to-be-tested sample (18).