Wavelength-scanning interferometer development using tunable laser

Abstract

A novel design for an external cavity diode laser that is not affected by mechanical noise and performs linear wavelength sweeps for the wavelength scanning interferometer system is studied. The proper design for the cavity will be suggested that can reduce mode hopping within the specific operating wavelength range. At a high speed, the performance of an external cavity diode laser that has a linear tuning range of 20 nm or more is reported. Using this tunable laser system, the wavelength scanning interferometer is designed and specimens having step height of 88 nm and 940 nm are measured with about three seconds time interval.