Patent ID: 7596288

Claim:
A micro displacement sensor, comprising: a first photonic crystal module comprising a first substrate and a plurality of first photonic crystals, the first photonic crystals being disposed on the first substrate and being arranged in a matrix, the first photonic crystals defining a first light-guide channel having a light input end and a light output end, the first light-guide channel comprises a first part and at least two second parts; a second photonic crystal module comprising a second substrate, disposed parallel to the first substrate, and having a plurality of second photonic crystals, the second photonic crystals being disposed on the second substrate and being arranged in a matrix, the second photonic crystals defining a second light-guide channel having a third part, a fourth part and a light detected end, the first part of the first light-guide channel spacing apart from the third part of the second light-guide channel by a row of the array of the first photonic crystals and a row of the array of the second photonic crystals, the first part of the first light-guide channel and the third part of the second light-guide channel being parallel and juxtaposed with each other thereby achieving an optical coupling therebetween, such that some light in the first part of the first light-guide channel can be coupled into the second light-guide channel via the third part; the second photonic crystal module configured for being caused to move relative to the first photonic crystal module thereby yielding a change in optical coupling efficiency of the optical coupling; a light source disposed adjacent to the light input end of the first photonic crystal module; and a detector disposed adjacent to the light detected end of the second photonic crystal module, the detector configure for detecting chances in light intensity of the counted light emitting from the light detected end due to the change in the coupling efficiency.