Title:
INSTRUMENT AND METHOD FOR MEASURING GEOMETRIC THICKNESS AND REFRACTIVE INDEX OF SAMPLE
Document Type and Number:
Japanese Patent JP3569726
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To speedily and securely measure the geometrical thickness and refractive index of a sample.
SOLUTION: The light from an LD 11 is split by a frequency shifter 12 into a couple of split lights; and one split light is reflected from a polarization beam splitter 17 to a reference mirror 18 and the other split light is reflected from the polarization beam splitter 17 to the sample 20. The split lights become interference lights thereafter to make a detector 25 generates an interference signal. An RMS-DC converter 32 finds the amplitude of the interference light of a detector 25 and a zero-cross comparator 27, a phase meter 28, and a lock-in amplifier 29 find a phase modulation factor. An arithmetic part 35 finds the movement distance needed for the focus to move from one surface to the other of the sample 20 and the increment of the optical path is found according to the phase modulation factor. Then the geometric thickness and refractive index of the sample are found according to the movement distance and the increment of the optical path.
Inventors:
Ichiro Yamaguchi
Fukano Ten
Fukano Ten
Application Number:
JP35673498A
Publication Date:
September 29, 2004
Filing Date:
December 15, 1998
Export Citation:
Assignee:
RIKEN
International Classes:
G01B11/02; G01B11/06; G01N21/45; (IPC1-7): G01B11/06; G01N21/45
Domestic Patent References:
| JP102855A | ||||
| JP10293019A |
Attorney, Agent or Firm:
Kenji Yoshitake
Hiroyuki Nagai
Junpei Okada
Kiyohiro Suzuki
Hiroyuki Nagai
Junpei Okada
Kiyohiro Suzuki