• Mark Nicholson

    Vice President of Operations, Zemax

    Mark Nicholson is vice president of operations at Zemax (Kirkland, WA).

    FIGURE 1. Global shape descriptors are shown for some common optical components.
    Mark Nicholson
    Jan. 1, 2013
    Recent design methods and software advances make it much easier to design aspheric surfaces that actually work in production and test by considering manufacturability issues at...
    In the design of a nonsequential system, the merit function curve is very choppy when just the base radius of curvature of a mirror is varied, so it is difficult to optimize (top). Pixel-interpolation routines improve the definition of the merit function by spreading the energy of a single ray to multiple pixels. The resulting merit function is smoother and indicates regions of minimized merit function and maximum on-axis brightness (center). Using the moment-of-illumination data, any slight change to the optical design that affects any ray is accounted for. The resulting merit function is far smoother (bottom).
    Mark Nicholson
    Dec. 1, 2007
    Computer-based design programs are now the standard design tool for optimization of imaging systems such as camera lenses and telescopes.
    FIGURE 1. Aspheric subaperture-stitching interferometry can be used to measure the surface figures of aspheres such as this ellipsoid (conic), which has a 100 mm aperture diameter, a base radius of -226 mm, and approximately 12 µm of aspheric departure. The asphere is fabricated from lightweighted silicon carbide with silicon cladding.
    Greg Forbes
    Feb. 1, 2007
    Distributed, mild aspheric surfaces and subaperture-stitching interferometry combine to form a cost-effective approach to fabricating aspheric optics.