Patent ID: 7499606
Filing Date: 2009-03-03
Classification: B82Y,G01D,G02B

Abstract:
1. A method for measuring micro displacements, comprising: (a) providing a micro displacement sensor, the sensor including a first photonic crystal module with a number of first crystals arranged in a first matrix and including a second photonic crystal module with a number of second crystals arranged in a second matrix, a laser source, and a detector, the first crystals and the second crystals having a same lattice constant “a”, the first matrix having a first light guide channel therein, the first light guide channel comprising a first horizontal channel, and a light exit and a light entrance, the second matrix having a second light guide channel therein, the second light guide channel comprising a second horizontal channel, and a detecting opening, the first horizontal channel and the second horizontal channel are formed with a row of the first crystal of the first matrix and a row of the second crystals of the second matrix disposed therebetween, the laser source being disposed at the light entrance of the first light guide channel, and the detector being located at the detecting opening of the second light guide channel; (b) securing the second photonic crystal module onto a first member of a device to be measured by a securing means, fixing the first photonic crystal module parallel to the second photonic crystal module on another member of the same device or on an unmovable second member with the another member of the same device or the unmovable second member being configured for measuring a relative micro-displacement, and ensuring that the first matrix is aligned with the second matrix and that the first light guide channel and the second light guide channel are optically aligned to provide a path for light from the first light guide channel to enter the second light guide channel; and (c) during operation, emitting light from the laser source, directing such emitted light into the first light guide channel, a first portion of the emitted light exiting from the first light guide channel and a second portion of the emitted light entering the second light guide channel; plotting changes in intensity of the light received by the detector to form a sine curve; analyzing the sine curve of the light intensity as a function of displacement to obtain a horizontal micro displacement of the first member relative to the second member.