Abstract by Nick Porter
Physics and Astronomy
Etalon interference laser wavelength metrology using webcams
Many fields of research require precise measurement of a laser's wavelength, but commercially available wavemeters are often too expensive, too large, or too fragile to be practical. We have designed and constructed a robust, compact, and inexpensive wavelength meter based on etalon interference—a phenomenon similar to thin-film interference. The device uses a webcam to measure the interference patterns caused by a series of etalons. Analyzing this etaloning across a range of known wavelengths provides a set of wavelength-dependent reference functions, which can be used to calculate an unknown wavelength within the same range. We present data showing that this device can measure a laser's wavelength with an average error less than a picometer, and a standard deviation less than 2 picometers.