Testing spherical surfaces: a fast, quasi-absolute technique

A technique for measuring the quality of spherical surfaces that provides a quasi-absolute result is presented. It requires only two measurement positions rather than the traditional method of absolute sphere measurement that requires three measurement positions. A measurement is taken with a mirror at the focus of the interferometer diverger lens and is subtracted from a measurement of the sphere tested at its center of curvature. This test assumes that the test sphere does not contain any aberrations with odd symmetry so that these aberrations can be subtracted to provide a fast, quasi-absolute measurement. We describe the new technique and compare measurement results from testing a X/ 12 peak-to-valley sphere (numerical aperture = 0.4) by using a phase-measuring Fizeau interferometer with results from the three-position absolute sphere measurement technique. The repeatability of this measurement technique is ±0.01 waves peak to valley

Picometer Level Spatial Metrology for Next Generation Telescopes

During the testing of the primary mirror segments for JWST, our team realized that some of the tools and techniques we had developed could be pushed further to achieve picometer resolution.We began developing incremental techniques for measuring, controlling, sensing to picometer levelsSeveral recent peer reviewed papers have shown that we can measure this level of change, control it with actuators, and potentially even develop active architectures using these ideasWe will show how the work on JWST evolved to systems applicable to measure picometer and even sub-picometer levels, show the results, and discuss implications for future telescope like LUVOIR and Habe

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

A wonderful life of holography, interferometry, and optical testing

The author had a very enjoyable career working with holography, interferometry, and optical testing and during this talk several projects the author worked on during his career will be discussed including 1) Use of computer generated holograms for testing aspheric optics, 2) temporal phase-shifting interferometry, 3) lateral shearing interferometry and adaptive optics, 4) computerized interference microscope, and 5) dynamic (single-shot) phase-shifting interferometry. It will be shown that as technology improves many things that were very difficult to do 30 or 40 years ago are now very simple to do and many ideas that were useless many years ago are now useful.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Amazing scatterplate interferometer

The scatterplate interferometer is an amazing instrument invented by James M. Burch in 1953 for testing optical components and it is especially good for testing concave mirrors. This interferometer requires no high-quality optical components and it generates its own reference wavefront without having a reference surface. The light source does not have to be a point source or monochromatic - almost any light source will work. The path lengths of the two interferometer paths are automatically matched and, regardless of the reflectance of the test mirror, the light intensities of the two interfering beams are matched. The interferometer is not very sensitive to vibration and it is inexpensive to build. There are several ways to use phase-shifting techniques with the interferometer. This talk will describe and explain the properties of the amazing scatterplate interferometer.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Moiré Pattern of Two Equally Spaced Circular Ring Patterns

Wave&#39;s theoryThis Demonstration shows the shape of the interference fringes in a plane containing the two point sourcesComponente Curricular::Educação Superior::Ciências Exatas e da Terra::Físic

Moiré pattern of two fresnel zone plates

Waves theoryThe Moiré pattern formed using two displaced Fresnel zone plates illustrates the straight line interference fringes produced by interfering two spherical waves having the same radius of curvature. The spacing of the straight line pattern depends on the separation between the centers of the two Fresnel zone plates, just like the spacing of interference fringes depends upon the separation between the two point sourcesComponente Curricular::Educação Superior::Ciências Exatas e da Terra::Físic

Moiré pattern of two fresnel zone plates

Waves theoryThe Moiré pattern formed using two displaced Fresnel zone plates illustrates the straight line interference fringes produced by interfering two spherical waves having the same radius of curvature. The spacing of the straight line pattern depends on the separation between the centers of the two Fresnel zone plates, just like the spacing of interference fringes depends upon the separation between the two point sourcesComponente Curricular::Educação Superior::Ciências Exatas e da Terra::Físic