Prof Gavin Dalton

Abstract:

As the first part of a development programme on computer-guided alignment(CGA), we model the alignment influence on the optical wavefront in terms of the phase and amplitude modulation. This modulation is derived from the interaction between alignment parameters and influence functions, both expressed in complex form. The alignment influence model is used to approximate the ray-traced target wavefront of a randomly mis-aligned multi-element system. The approximated wavefront shows a factor of ∼ 100 improvement in predicting the target, when coupled non-linear influences among elements are included. This demonstrates the significance of the inter-element effect. We discuss the possibility of adopting the model for rectifying mis-alignment of multi-element systems. © 2007 Optical Society of America.

Abstract:

We discuss the implementation of the complex wavefront modulation model in practical optical alignment procedures and present its interim results. This modulation model describes the relation between the alignment state and the wavefront of a system, both are expressed in mathematical complex quantities. It addresses the importance of the coupled inter-element alignment effect to the resultant system wavefront. We utilise this effect in order to extract the alignment state of a system from measured optical wavefronts. We demonstrate the method's practical applicability to the real optical alignment procedure by showing alignment simulations of a centered three-mirror system.