Optical setups are not always perfectly aligned, and it may be of interest how variations of some geometrical parameters influence the performance of a device. SPRAY simulations can help to investigate misalignment effects. This is shown in the following simple example.
Ideal alignment leads to a throughput of the reflectance unit of 100% (ideal mirrors are assumed):
If the sample is moved up from its ideal position by 5 mm no rays reach the detector any more:
In order to investigate how the detector signal decreases with sample position many SPRAY simulations have to be performed. Using OLE automation the sample height can be automatically varied by an Excel macro, the detector signal is recorded and the following display of the detected fraction of rays vs. the z coordinate of the sample is generated:
For almost normal incidence of light
the z-alignment of the sample is significantly less critical:
