Atomic force microscope using a single light source to drive cantilever vibrations and sense cantilever motions

A method of operating an atomic force microscope (AFM), the method comprising:

• modulating a light source directed to a cantilever with a tip to cause cantilever vibrations and to measure cantilever motions due to engagement of the tip with a sample of interest;
• detecting light of the light source reflected from the cantilever to measure the cantilever motions;
• and
• using measured cantilever motions to acquire AFM data of the sample of interest.

An atomic force microscope (AFM) comprising:

• a cantilever with a tip to engage a sample of interest;
• a light source to emit light onto the cantilever;
• a driving system operably configured to operate the light source at constant intensity for first time periods followed by second time periods with a light intensity from the light source reduced, wherein the second time periods cause cantilever vibrations and the first time periods are used to measure cantilever motions;
• a photodetector positioned to detect the light reflected off the cantilever to measure the cantilever motions;
• and
• a processing device operably coupled to the photodetector to receive measured cantilever motions to acquire AFM data of the sample of interest.