# Tailoring the V-Model for Optics: A Methodology for Optomechatronic Systems
## 3 Concretization of the V-Model for High Resolution Lighting Systems
#### 3.2.1 Design Steps for the Sequential Detailed Design (SC-Design)
The type of optimization can be divided into so-called \"local\" and \"global\" optimization [53]. In the early phase of the design process, \"global\" optimization is particularly suitable for an initial estimation. As the sequential detailed design matures, effective improvements can be achieved quickly using \"local\" optimizations. The algorithm for the optimization of the detailed design has to be chosen depending on the function of the optical system (imaging or illuminating) as well as on the selected optimization type. Especially developed for detailed designs of optical systems, algorithms that operate according to the \"Damped Least Squares\" method are generally suitable [71]. The number of optimization cycles to be performed has to be defined depending on the design progress. Similar to the definition of variable parameters, a limited number of cycles is recommended in the early phase of the design process, which can be increased with the growing maturity of the sequential detailed design. * **Evaluate image quality of the SC-Design:** On the basis of the design of an imaging optical system, the image quality of the sequential detailed design must be evaluated  
Figure 9: Method for the sequential and non-sequential detailed design of high-resolution lighting systems according to [17]. after the optimization step. For the design of illumination optics, this step can be skipped. Different criteria such as modulation transfer function (MTF), point spread function (PSF), encircled energy (EE), RMS spot radius, wavefront, and aberrations are used to evaluate the image quality [51; 52; 72; 73]. The choice or suitability of an evaluation criterion is significantly influenced by the subsequent field of application of the optical system. For example, detailed designs of lenses used in the field of photography are evaluated using the MTF, and optical designs of LiDAR systems are often evaluated using the EE criterion [74; 75; 76; 77]. In case the required image quality of the sequential detailed design is not met, return to step \"Set functional surfaces and parameters\" (cf. Figure 9). If the requirements for the image quality are not met despite repeated runs through this loop, the preliminary design of the high-resolution lighting system must be revised (cf. Figure 9). * **Assign tolerances:** Since deviations due to manufacturing and alignment affect the image quality of the sequential detailed design, tolerances must be assigned to the individual functional surfaces and the image quality must be re-evaluated. Deviations caused by the manufacturing process (ultra-precision turning, CNC machining, etc.) must be taken into account by tolerancing the detailed design with regard to the position and surface of the functional surfaces. The influence of alignment-related deviations of individual optical elements in the manufactured optical system can be taken into account by decentering and tilting the functional surfaces in the sequential detailed design. If the requirements for the image quality of the sequential detailed design are met, while taking the assigned tolerances into account, one can continue with the assembly of the non-sequential detailed design. Otherwise, return to the step \"Set functional surfaces and parameters\".