Highly coherent tunable semiconductor lasers in metrology of length

Abstract

Laser diodes became the most widespread lasers and now are available in a broad spectrum of wavelengths ranging from infrared to the visible region. The low power ones mainly those with the quantum well structure and gain or index guided configuration perform a narrow linewidth and soon became a favourite tool for interferometry and spectroscopy. The need for continuous tuning range led to the development Extended Cavity Laser systems (ECL) and Vertical Cavity Surface Emitting Lasers (VCSEL). Both systems seem to be promising laser sources for design of optical frequency standards or interferometric distance measurement devices. We present design of these laser systems and their applications in metrology of length.