Imageamento Óptico com Fotodetector de Elemento Único

With the advent of the laser in the 1960s, new microscopy techniques were developed, some of which even made it possible to obtain superresolved images. In this scenario, the SPIFI (SPatIal Frequency-modulated Imaging) technique has stood out for presenting a relatively simple optical assembly, with fast image acquisition and being suitable for scattering media. This imaging technique uses a focal line as a light source on the sample and performs detection using a single photodetector. The focal line is modulated in intensity by a rotating mask (Lovell reticle), encoding each part of the line with a different frequency. The deconvolution of the SPIFI signal collected by the photodetector, performed using a Fourier Transform (FFT), allows for obtaining the signal in the frequency domain, indicating the luminous intensity for each section of the focal line. The composition of the object image can then be obtained by scanning this focal line over the sample. The present study aims to present this frontier technique with a simplified assembly, which can be developed in teaching laboratories, making it more accessible, but still with the inherent benefits of the SPIFI technique.

Keywords:
Optical imaging; SPIFI; Microscopy; Spatial-frequency modulation; Single-element photodetector