Interferometric characterization of phase masks.
We demonstrate a novel interferometric technique for highly accurate characterization of phase masks used in optical fiber grating fabrication. The principle of the measurement scheme is based on the analysis of the interference pattern formed between the first- and zero-order beams transmitted through or reflected from the grating under test. For spatial resolution of a few millimeters, our methods allow the determination of local variations of the order of 1-microm grating period with an accuracy of a few picometers. These methods are applicable to a broad class of diffractive grating structures.
Sumetsky
Mikhail
M
OFS Laboratories, 600 Mountain Avenue, Murray Hill, New Jersey 07974, USA. sumetski@ofsoptics.com
Dulashko
Yury
Y
White
Tom P
TP
Olsen
Tim
T
Westbrook
Paul S
PS
Eggleton
Benjamin J
BJ