Patent ID: 8654340

Claim:
A near field detection device for the imaging of an object, the 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 converter 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; a wavelength modifier adapted so that the wavelength of the progressive signal injected into the laser cavity is different from the original wavelength; a first optical isolator positioned in the path of the original light signal so as to avoid propagation of a reflected optical signal towards the laser cavity; and wherein the re-injector further includes a second optical isolator positioned in the path of the progressive signal of the evanescent wave to prevent propagation of a reflected optical signal towards the converter.