The optimization and uncertainty analysis of laser-based optical sensors in the design phase is a challenging task due to the presence of stochastic laser speckle effects. We present an accurate, efficient, and versatile simulation framework for the design of optical sensor assemblies, capable of handling objective as well as subjective speckle effects. The framework integrates the stochastic nature of laser speckle with the deterministic properties of ray-tracing simulations, enabling the simulation of sensitivities to translational as well as rotational target motion and reliable performance estimation, even for more complex optical assemblies. To validate the simulation results for translation and rotation, they are compared against the experimental data of four speckle-based optical sensor assemblies as well as against analytical relations for speckle pattern motion. The accuracy of the developed framework is demonstrated by simulation errors for correlation peak shift of the speckle pattern of less than 2 μm rms and 2.4 μm rms for translation and rotation, respectively. For the center of gravity shift as additional simulation output for an integrated laser sensor for sensing translations in all three degrees of freedom, a simulation error of 2.6 μm rms was obtained, which also lies well below the resolution of the designed optical sensor assemblies.
This paper presents the development of a versatile, accurate and efficient speckle simulation tool for the design of laser-based displacement sensors, capable of handling objective as well as subjective speckles. The simulation tool integrates the statistical nature of speckles with the deterministic properties of ray-tracing simulations, providing a reliable estimation of the performance of laser and/or speckle-based sensors in the design phase, even for more complex optical assemblies. It enables the calculation of several simulation outputs in order to determine the best performing system configuration for a given requirement and measurement principle. To validate the simulation results, they are compared against the experimental data of four designed laser-speckle based sensor setups for measuring in- and out-of-plane displacement of a target as well as against analytical relations for describing speckle pattern translation for simple geometries. With resulting simulation errors of less than 2 µm rms for in-plane (output: correlation peak shift) and 2.6 µm for out-of-plane displacements (output: center of gravity shift) for an integrated laser sensor geometry, the good accuracy of the speckle simulation tool is demonstrated.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
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.