Laser-dilatometer calibration using a single-crystal silicon sample

• Main Authors: Ines Hamann, Josep Sanjuan, Ruven Spannagel, Martin Gohlke, Gudrun Wanner, Sönke Schuster, Felipe Guzman, Claus Braxmaier
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2019-01-01
• Series: International Journal of Optomechatronics
• Subjects: dilatometry; silicon; differential wavefront sensing; simulation
• Online Access: http://dx.doi.org/10.1080/15599612.2019.1587117

Marginal changes in geometrical dimensions due to temperature changes affect the performance of optical instruments. Highly dimensionally stable materials can minimize these effects since they offer low coefficients of thermal expansion (CTE). Our dilatometer, based on heterodyne interferometry, is able to determine the CTE in range. Here, we present the improved interferometer performance using angular measurements via differential wavefront sensing to correct for tilt-to-length coupling. The setup was tested by measuring the CTE of a single-crystal silicon at 285 K. Results are in good agreement with the reported values and show a bias of less than 1%.