Robert Smythe

President, Äpre Instruments
Phone: 5206398195

Robert Smythe is president of Äpre Instruments (Tucson, AZ).

(Courtesy of Äpre Instruments)
FIGURE 1. When the SCI produces a single laser line, the fringe contrast is the same everywhere; this is the laser Fizeau mode (top). The spectral width determines the width of the interference fringes, just like a broadband source (bottom).
Test & Measurement

Understanding spectrally controlled interferometry

July 14, 2023
Revolutionary innovations are rare. In the field of optical test interferometry, the HeNe laser revolutionized its application and use; now, SCI promises to do the same.
FIGURE 1. A card printed with 1 mm black/white line pairs oriented horizontally (a) and vertically (b) can be used to assess vertical and horizontal interferometer imaging performance, respectively. Image degradation is seen at the edges of the image in this Gen II interferometer, indicating limitations in spatial frequencies that can be measured.
Test & Measurement

Interferometry: Three simple tests assess interferometer performance

Nov. 4, 2016
How good is your interferometer? Has system performance degraded since last year? How does one system compare to another? Do annual "calibrations" provide the complete picture...
FIGURE 1. A unique asphere metrology system uses a standard laser Fizeau interferometer and a displacement-measuring interferometer to sweep out the whole surface from center to edge in a common-path configuration, ensuring low measurement uncertainty.
Test & Measurement

INTERFEROMETRY: Asphere interferometry powers precision lens manufacturing

Oct. 1, 2006
A large-aperture, low-uncertainty laser Fizeau interferometer with highly expanded dynamic range enables accurate qualification of high-performance aspheric optics.