Substrate unit of nanostructure assembly type, optical imaging apparatus including the same, and controlling method thereof

An optical image apparatus comprising:

• a lower substrate including a main surface perpendicular to a first direction;
• an upper substrate separated from the lower substrate, an observation object being able to be positioned at the upper substrate;
• at least one metal nanostructure positioned on the lower substrate;
• a position controller for controlling at least one position of the upper substrate and the lower substrate;
• and
• a light source positioned under the lower substrate and for irradiating light to the lower substrate,
• wherein the position controller controls a position of at least one of the lower substrate and the upper substrate in a second direction perpendicular to the first direction.

A controlling method of an optical image apparatus including a lower substrate, an upper substrate, and a position controller, the method comprising:

• separating the upper substrate at which an observation object is positioned and the lower substrate from each other by a first distance according to a replacement requirement control signal;
• assembling or separating at least one metal nanostructure on or from the lower substrate;
• and
• controlling a distance between the upper substrate and the lower substrate within a second distance smaller than the first distance according to an observation requirement control signal,
• wherein the second distance is determined depending on a depth of a local electric field formed by the at least one metal nanostructure.