Patent ID: 8405835

Claim:
A scanning microscope using a heterodyne interferometer comprising: a heterodyne interferometer comprising: a laser which delivers a probe beam to a sample; a first beam splitter which mixes the probe beam reflected from or transmitted through the sample back into the heterodyne interferometer and a reference beam to generate a heterodyne beat signal which carries phase and amplitude change in the probe beam; a second beam splitter which provides a local oscillator (LO) signal for radio frequency (RF) mixing based on the probe beam; and an I/Q-demodulator which demodulates the heterodyne beat signal to provide I- and Q-signal based on the heterodyne beat signal and the local oscillator signal; a scanner which scans the sample in two directions perpendicular to a propagating direction of the probe beam; a scanner driver which actuates the scanner; a focusing device which focuses an output probe beam from the heterodyne interferometer onto a surface or inside of the sample; a collimating device which collimates the probe beam reflected from or transmitted through the sample; an analog to digital (A/D) converter which digitizes the output I-signal and Q-signal from the heterodyne interferometer; and a computer which receives, stores, and processes the I- and Q-signal from the A/D converter to simultaneously obtain phase and amplitude information of the probe beam from the I- and Q-signal, extracts structural and/or material information for the sample using the obtained phase and amplitude information, and transfers control commends for actuating the scanner to the scanner driver.