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![Figure 1-4. Typical metal cutting operation [10].](profile/Charan-Bodlapati/publication/337745521/figure/fig3/AS:832492722475010@1575493140322/4-Typical-metal-cutting-operation-10_Q320.jpg)
![Figure 1-6. Force diagram for orthogonal cutting process [10].](profile/Charan-Bodlapati/publication/337745521/figure/fig5/AS:832492722483200@1575493140367/6-Force-diagram-for-orthogonal-cutting-process-10_Q320.jpg)
direction of Dr. Thomas Dow). Optical devices are extremely important since they play a critical role in optical recording and display. Single point diamond turning is one of the most common methods to create plastic optics. Diamond turning of plastics is influenced by a wide variety of factors such as the glass transition temperature of the polyme...
Citations
... Using a 50× objective, the roughness of the lens was measured to have an Sa of around 0.041 µm. While the surface finish is slightly higher than the typical diamond machined products, this corroborates well with the machining parameters when machining PMMA [15,16]. For the lens profile however, there were a few challenges encountered in the measurement of such optical structures. ...
High fill factor for Fresnel lens arrays has been achieved with the aid of polygonal lenses. This has been done for both circular trimmed lenses and full polygonal lenses, both of which present some optical drawbacks. The composite polygonal Fresnel lens (CPFL) avoids these issues with its unique design – a radial symmetric Fresnel center filling into a polygon, avoiding any intersecting facets within the lens by introducing fillets. To manufacture the CPFL, diamond shaping is applied to not only meet the strict standards required for optical fabrication but also maneuver around the curvilinear features that cannot be fabricated using conventional turning techniques. As such, direct diamond shaping (DDS) was employed to generate an array of CPFLs on a PMMA substrate. Optical simulation was used to validate the performance of the CPFL before production of the lens array, followed by testing of the fabricated lenses, showing less overall noise with better focus compared to conventional polygonal lenses.
