Effects of pupil filter patterns in line-scan focal modulation microscopy

Abstract

Line-scan focal modulation microscopy (LSFMM) is an emerging imaging technique that affords high imaging speed and good optical sectioning at the same time. We present a systematic investigation into optimal design of the pupil filter for LSFMM in an attempt to achieve the best performance in terms of spatial resolutions, optical sectioning, and modulation depth. Scalar diffraction theory was used to compute light propagation and distribution in the system and theoretical predictions on system performance, which were then compared with experimental results.

Three‐dimensional cellular imaging in thick biological tissue with confocal detection of one‐photon fluorescence in the near‐infrared II window

“…This problem can be alleviated by introducing additional background rejection mechanisms beyond spatial filtering provided by confocal detection . For example, focal modulation has been demonstrated to be very effective in suppressing scattering induced background in visible light confocal microscopy .…”

Quadrature demodulation in line‐scan focal modulation microscopy for imaging three‐dimensional zebrafish neural structure

“…In the field of signal processing, the most common method to demodulate a modulated carrier wave is to use a product detector . This method was also used in the previous LSFMM image demodulation . Basically, it multiplies the modulated image with a mask image with the same frequency f 0 to produce a copy of the original focal component and a modulated component at twice the carrier frequency 2 f 0 .…”

“…Here the STPM is the core part to achieve focal modulation, which consists of an electro‐optics modulator (EOM; EO‐PM‐NR‐C4‐EO phase modulator, Thorlabs), a customized spatial polarizer and a polarization analyzer (GTH10M‐A, Mounted Glan‐Thompson Polarizers, Thorlabs). The theories and schematics of LSFMM have been adequately described in the previous publication and is therefore no longer repeated here. We were adopting a slit‐scanning method to fully utilize the large sensing area of the camera (1920 × 1080 pixels, 6.5 μm in pixel size).…”