Single Mode Laser Diodes
Fabry Perot Laser Diodes

Direct Access
Fabry-Perot Laser Diodes operate on a single transverse resonator mode leading to an output which is diffraction-limited. However, multiple axial (longitudinal) modes may occur which can lead to differing optical frequencies. The frequencies are separated by the free spectral range of the resonator given by the reflecting facets of the laser chip.