RESUMO
A versatile THz/IR near field microscope is demonstrated. Collecting the scattered light from a THz in-situ subwavelength source, this microscope provides images with resolution better than lambda/10. The physical origin of the contrast is explained by a Mie scattering diffraction model. Owing to the classical nature of this microscope working in the near field, resolution of THz/IR images is improved using deconvolution process.
Assuntos
Raios Infravermelhos , Iluminação/instrumentação , Microscopia/instrumentação , Micro-Ondas , Desenho de Equipamento , Análise de Falha de Equipamento , Iluminação/métodosRESUMO
We have developed a white-light interference microscope for ultrahigh-resolution full-field optical coherence tomography of biological media. The experimental setup is based on a Linnik-type interferometer illuminated by a tungsten halogen lamp. En face tomographic images are calculated by a combination of interferometric images recorded by a high-speed CCD camera. Spatial resolution of 1.8 microm x 0.9 microm (transverse x axial) is achieved owing to the extremely short coherence length of the source, the compensation of dispersion mismatch in the interferometer arms, and the use of relatively high-numerical-aperture microscope objectives. A shot-noise-limited detection sensitivity of 90 dB is obtained in an acquisition time per image of 4 s. Subcellular-level images of plant, animal, and human tissues are presented.
