Two-wavelength whole-field interferometry setup for thermal lens study

Danilo M. Silva; Eduardo A. Barbosa; Niklaus U. Wetter

doi:10.1117/12.978186

11 September 2012 Two-wavelength whole-field interferometry setup for thermal lens study

Danilo M. Silva, Eduardo A. Barbosa, Niklaus U. Wetter

Proceedings Volume 8413, Speckle 2012: V International Conference on Speckle Metrology; 841319 (2012) https://doi.org/10.1117/12.978186
Event: SPECKLE 2012: V International Conference on Speckle Metrology, 2012, Vigo, Spain

Abstract

In this paper we present a new approach for thermal lens analysis using a two-wavelength DSPI (Digital Speckle Pattern Interferometry) setup for wavefront sensing. The employed geometry enables the sensor to detect wavefronts with small phase differences and inherent aberrations found in induced lenses. The wavefronts was reconstructed by four-stepping fringe evaluation and branch-cut unwrapping from fringes formed onto a diffusive glass. Real-time single-exposure contour interferograms could be obtained in order to get discernible and low-spacial frequency contour fringes and obtain low-noise measurements. In our experiments we studied the thermal lens effect in a 4% Er-doped CaO-Al₂O₃ glass sample. The diode lasers were tuned to have a contour interval of around 120 μm. The incident pump power was longitudinally and collinearly oriented with the probe beams. Each interferogram described a spherical-like wavefront. Using the ABCD matrix formalism we obtained the induced lens dioptric power from the thermal effect for different values of absorbed pump power.

Citation Download Citation

Danilo M. Silva, Eduardo A. Barbosa, and Niklaus U. Wetter "Two-wavelength whole-field interferometry setup for thermal lens study", Proc. SPIE 8413, Speckle 2012: V International Conference on Speckle Metrology, 841319 (11 September 2012); https://doi.org/10.1117/12.978186

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available