Transmission-type angle deviation microscope with NA=0.65 for 3D measurement

摘要

Transmission-type laser scanning angle deviation microscopy (TADM) with NA=0.65 for three dimension (3D) measurement is presented. It is based on the theorems of geometrical angular deviation and surface plasmon resonance (SPR) and the use of the common-path heterodyne interferometry. When a laser beam defocuses on the surface of a transparent sample, the transmission light will be deviated a small angle from the optical axis and the deviation angle is proportional to the defocus length and the square of the numerical aperture. We used a SPR angular sensor and the common-path heterodyne interferometry to measure this deviation angle. Scanning the sample, the phase profile was measured and transferred to surface height pattern, the 3D surface profile was obtained in real-time. The results showed that the dynamic range and lateral and axial resolutions were equal to ±5.6 gm, 0.3 gm, and 3 nm, respectively.