Method and apparatus for measuring the thickness of a film using

Details Method and apparatus for measuring the thickness of a film using Method and apparatus for measuring the thickness of a film using

1995-08-28

1997-06-24

Font, Frank G.

Optics: measuring and testing

By configuration comparison

With photosensitive film or plate

356382, 356357, G01B 902, G01B 1106

Patent

active

056421966

ABSTRACT:
An apparatus and method for measuring the thickness of a film having top and bottom surfaces. The apparatus includes a first coupler for generating a first probe light signal and a second probe light signal from a low coherence light source. The first probe light signal is directed toward the top surface of the film and the light leaving the top surface of the film is collected. Similarly, the second probe light signal is directed toward the bottom surface of the film and the light leaving the bottom surface of the film is also collected. Top and bottom partially reflecting reference surfaces are provided for generating reflections. The top reference surface reflects part of the light leaving the top surface back toward the top surface, and the bottom reference surface reflects light leaving the bottom surface of the film back toward the bottom surface of the film. The collected light is combined to form a collected light signal which is input to a receiver that determines the time delay between light reflected from the top surface of the film and the top reference surface and between the bottom surface of the film and the bottom reference surface. In the preferred embodiment of the present invention, the receiver is constructed from an optical autocorrelator or an optical spectrum analyzer that includes circuitry for providing the Fourier transform of the frequency domain spectrum measured from the collected light signal.

REFERENCES:
patent: 5323229 (1994-06-01), May et al.

Affiliated with

Also associated with

Rating

Method and apparatus for measuring the thickness of a film using does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for measuring the thickness of a film using, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for measuring the thickness of a film using will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-152147