Heterodyne detection device for imaging an object by re-injection

A near field optical microscope comprising a detection device comprising:

• a laser cavity adapted for emitting an original light signal at an original wavelength towards the object so as to generate an evanescent wave at the surface of the object;
• a microtip operably converting the evanescent wave into a progressive signal;
• a re-injector operably injecting the progressive signal in the laser cavity so as to generate interferences within the laser cavity between the progressive signal and the original light signal;
• a detector operably detecting the interferences so as to determine at least one physical characteristic of the object;
• and
• a wavelength modulator adapted so that the wavelength of the progressive signal injected into the laser cavity is different from the original wavelength.

A detection method for the imaging of an object, the method comprising:

• a laser cavity emitting an original light signal at an original wavelength towards the object so as to generate an evanescent wave at the surface of the object;
• converting the evanescent wave into a progressive signal;
• injecting the progressive signal into the laser cavity so as to generate interferences within the laser cavity between the progressive signal and the original light signal;
• detecting the interferences so as to determine characteristics of the object;
• and
• the wavelength of the progressive signal injected into the laser cavity being different from the original wavelength.