In an ordinary microscope, a sample is illuminated by a uniform light and the reflected or transmitted, or scattered light is to provide image through objective and imaging lenses and the image is directly observed by a naked eye through an eyepiece lens.
On the other hand, in a scanning laser microscope, the beam spot of laser out of the light source is narrowed down to the size equivalent to its wavelength and the beam of this spot size is scanned two dimensionally on the sample surface.
The reflected light from the sample is detected by a light detector.
The time series detector output is sampled in synchronization with two dimensional scanning and an image is generated by rearranging the signal two dimensionally.
The signal output at certain moment originates only to the light from a certain point on the sample where beam spot is irradiating at that certain moment and an image of high contrast is obtained, accordingly. |
