Title:
【発明の名称】干渉計
Document Type and Number:
Japanese Patent JP2650953
Kind Code:
B2
Abstract:
A wavelength tracking compensator for a laser interferometer measurement system comprises a stable physical standard optical cavity (11) and a double path, differential interferometer mounted on a baseplate. The interferometer (13) monitors the apparent changes in the cavity's length caused by actual changes in the index of refraction of the surrounding air. The cavity (11) is supported with a temperature compensated mount (31,32) that utilizes the principle of differential thermal expansion of two different metals to create a mount which exactly matches the coefficient of expansion of the cavity material. A semi-kinematic mount (51) supports the double path, differential interferometer and allows the interferometer to be accurately aligned to the cavity with three rotational degrees of freedom to prevent any cosine error in the cavity's optical path length measurement, to prevent polarization leakage, and to maximize optical power at the receiver. A phase measurement system interpolates between interference fringes to extend measurement resolution and provides absolute phase information relative to the fringes so that the measurement system can prevent measurement uncertainty caused by a beam interruption and recover from an interruption without re-initialization.
Inventors:
SUKOTSUTO EMU DETORO
ARAN ETSUCHI FUIIRUDO
ARAN ETSUCHI FUIIRUDO
Application Number:
JP6494988A
Publication Date:
September 10, 1997
Filing Date:
March 18, 1988
Export Citation:
Assignee:
HYUURETSUTO PATSUKAADO CO
International Classes:
G01B9/02; G01B11/00; G03F7/20; (IPC1-7): G01B9/02; G01B11/00
Domestic Patent References:
| JP63135809A | ||||
| JP59227042A | ||||
| JP6242117U |
Attorney, Agent or Firm:
Hideo Ueno