white light confocal MicroscopeIt is a high-precision microscopy device that combines confocal imaging technology with white light illumination, which can achieve high-resolution and high contrast 3D imaging of samples. Its core working principle revolves around the design of confocal optical path and multi band imaging of white light source, as follows:

1、 Core structural foundation

　　white light confocal MicroscopeThe core components of the system include a white light source module (usually a halogen lamp or LED composite light source), a pinhole aperture group, a scanning galvanometer, an objective lens, a spectroscopic system, and an image detector. The pinhole aperture is a key component for achieving confocal imaging.

2、 Optical transmission and imaging process

The light source emits a mixture of continuous spectrum light from a collimated white light source, which is processed by a collimating lens to form a parallel beam, and then directed to the objective lens by changing the direction of the light path through a beam splitter (half mirror).

After the sample irradiation and signal excitation parallel beams are focused by the objective lens, a small light spot is formed and projected onto the surface of the sample. Different parts of the sample reflect, scatter, or absorb light of different wavelengths of white light, and the reflected/scattered light signals will return along the original optical path, pass through the objective lens again, and enter the spectroscopic system.

The screening function of confocal pinhole is the core link of confocal technology:

The light signal returned from the sample focal plane can accurately pass through the confocal pinhole and enter the subsequent detector after being reflected by the spectroscope;

However, stray light outside the focal plane (signals from non focal areas) cannot pass through the pinhole due to the divergence of the optical path, and will be intercepted by the pinhole baffle, making it unable to participate in imaging.

This process achieves the "optical slicing" effect, eliminating background interference from non focal planes.

The signal splitting and detection of the white light signal passing through the pinhole will enter the splitting module, which splits the white light by wavelength through a filter or grating (such as the red, green, blue and other channels in the visible light band). The light signals in different bands are received by corresponding detectors and converted into electrical signals.

Image reconstruction and presentation: The scanning galvanometer controls the focused spot to perform point by point and line by line two-dimensional scanning on the surface of the sample. The detector synchronously collects signals from each scanning point, and then the computer system converts the electrical signals into pixel points and concatenates them into a two-dimensional image; If scanning layer by layer along the Z-axis (sample depth direction), the three-dimensional structure reconstruction of the sample can also be achieved by stacking multiple layers of two-dimensional images.

3、 Technical characteristics of white light confocal microscopy

Compared to laser confocal microscopy, white light confocal microscopy does not require multiple laser sources and can achieve multi band imaging through a single light source, reducing equipment costs and optical path complexity;

Based on the broad spectral characteristics of white light, it can simultaneously obtain optical information of samples in different visible light bands, which is more suitable for imaging observation of natural pigments and unlabeled samples;

The screening mechanism of confocal pinhole enables its imaging resolution and contrast to be much higher than ordinary white light microscopes, and can achieve non-destructive 3D tomographic imaging.