A method to calculate element misalignments in optical systems is presented. The method uses the wavefront information in the exit pupil in the form of Zernike coefficients and a function that relates them to the misalignment values. Three different functions with its calculation procedures have been studied: in the first one, a nonlinear equations system is used by the authors to show the complexity around misalignments computing; in the next two, a single artificial neural network (ANN) and a procedure with two ANNs overcome the limitations of the equations systems. It is shown that for misalignments being small perturbations of position around the nominal value, the Zernike coefficients’ behavior in front of misalignments can be approximated with a polynomial expression. But for combinations of both decenter and tilt the problem becomes too complex to be solved analytically, therefore, we have used ANNs to solve it. The method is validated by simulation for each of the functions, using a triplet where the second lens is misaligned, and the results are compared.
A new method for the misalignments calculation has been developed based in the analysis of the coefficients of the
Zernike polynomial adjustment to the on-axis wavefront of the optical system. By means of a study of the system
behavior in front of misalignments when they are small perturbations of position around the nominal value, it is shown
that the Zernike coefficients behaviour can be aproximated with a polynomial. The coefficients of the Zernike
polynomial are used to form a system of non-linear equations where the unknown variables are the misalignment values.
This system of equations can be solved to find the misalignments values. The method has been validated by the
simulation of a triplet where the second lens is misaligned. A series of misalignments of decentering and tilt have been
applied and by simulation the wavefront have been obtained. Then the method has been used to calculate the
misalignments from the wavefronts. Good results have been obtained for decentering and tilt separetely. With this
process, the error of calculation for the tilt and the decentering has been obatined to be less than 20% for the simulated
triplet system.
We present a new strategy to calculate an optimized refractive freeform surface for illumination purposes with a LED source. The goal of this paper is to present a new iterative flux based strategy to design plastic lens for LED lighting solutions. The new strategy considers the energy emission pattern of the LED and adjusts a plastic refractive surface to accomplish the target intensity distribution. This paper is divided in four parts, a brief introduction to LED systems and reviewing optical design strategies, the method of calculus is exposed in the second part, third part presents the results for a particular refractive optical design developed by new presented algorithm and finally, a set of conclusions about strategy is showed in fourth part.
The proper alignment of the individual elements in an optical system is a crucial point in the
final performance of an optical system. The developed method we present is aimed to detect
and quantify misalignments of decentering and tilt in imaging optical systems with a non-expensive
system. This method is based in the comparison of different image parameters
values. These parameters values are obtained through the analysis of the image formed by
the optical system under study of an object composed of an array of point sources. The
method has been validated by obtaining the behavior curves of the parameters for a gauss
system in front of decentering up to 0.3mm and tilt up to 1°.
The proper alignment of the individual elements is a crucial point in the final performance of an optical system. The
alignment technique we present uses the image formation of a point sources array to detect the misalignments of an
imaging system. We have displaced the analysis plane from the exit pupil plane to the image plane, where the PSFs
functions are captured on a sensor. The PSFs are large enough to be sensitive to the misalignments and we are able to
detect them using image analysis techniques. The proposed technique is a solution when more than one field position is
necessary to obtain a well-balanced quality function over all the field of view. We have been studying this method on a
particular collection of optical systems with decentering and rotation errors, achieving an accuracy of 0.1mm for
decentering and 0.01° for rotation.
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