Measurement of thermo-elastic deformation of an optic using a polarization-based shearing interferometer.
Appl Opt
; 51(31): 7426-33, 2012 Nov 01.
Article
em En
| MEDLINE
| ID: mdl-23128687
ABSTRACT
A shearing interferometer is presented that uses polarization control to shear the wavefront and to modulate the interference pattern. The shear is generated by spatial walk-off in a birefringent crystal. By adjusting the orientation of the birefringent crystal, the components of the wavefront gradient can be independently measured to allow determination of the full wavefront vector gradient as well as reconstruction of the wavefront. Further, the monolithic nature of the crystal used for shearing allows the interferometer to be set up without need for precise alignment of any components. An algorithm incorporating homodyne detection is presented, which analyzes the modulated interferograms to determine the components of the wavefront gradient, from which the wavefront is reconstructed. The thermal deformation of a mirror subject to heating from absorption of a Gaussian pump beam was accurately observed with a sensitivity better than λ/160. We show that this sensitivity is scale invariant, and present a method to account for the nonuniform spatial frequency response of the interferometer.
Texto completo:
1
Bases de dados:
MEDLINE
Idioma:
En
Revista:
Appl Opt
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Estados Unidos