High-speed confocal imaging with programmable multi-beam scanning

Laser scanning confocal microscopy (LSCM) is a widely used technique for high-resolution, three-dimensional imaging of biological tissues and material structures. Despite its effectiveness, conventional LSCM systems are inherently limited by sequential point-by-point scanning, which results in slow image acquisition, and by a fixed aperture (pinhole) that restricts adaptability. To overcome these limitations, we propose an advanced LSCM system that integrates programmable multi-beam illumination and computational multi-aperture to enhance imaging speed, flexibility, and contrast. Using the computer-generated holography (CGH) technique, the proposed system creates multiple, independently controllable beams through a liquid crystal spatial light modulator (LCSLM). This enables simultaneous scanning of multiple points across the sample, significantly enhancing the image acquisition speed without compromising the spatial resolution. On the detection side, multi-apertures are created computationally to selectively block out-of-focus light from each scanned point. This dynamic control enhances image contrast and resolution by adapting in real time to sample-specific conditions. The dual programmability in both the illumination and detection paths introduces a new level of flexibility in confocal imaging. Proof-of-concept simulation and experimental results are provided that demonstrate the system’s capabilities, showing marked improvements in speed and flexibility over traditional systems.