Thin Films Sing a New Tune
The growth of wavelength division multiplexing (WDM) fiber optic networks greatly accelerated the demand for tunability in components such as optical channel monitors, add/drop data filters, lasers and receivers. As a result, virtually every type of dispersive element used in telecom — fiber Bragg gratings, microelectromechanical systems (MEMS) Fabry-Perots, waveguides, diffraction gratings — has seen the development of a tunable version.
Until recently, however, thin-film interference...
Photonics Spectra, November 2004