Dynamic properties of single mode semiconductor lasers have been investigated using different optical set-ups. Intergrated optical self-homodyne and heterodyne systems were mounted to measure the intensity (IM) and frequency (FM) modulation responses and to obtain the linewidth enhancement factor (a) of three single-section distributed feedback lasers (DFB). The self-homodyne interferometric system was used for the first time to obtain the linewidth enhancement factor. This system is more stable, reproducible and practical than the heterodyne set-up, since it is possible to obtain IM, FM characteristics and a parameter in one measurement without using another semiconductor lase as a local oscillator. The other system used was the Mach-Zehnder interferometer with balanced detection mounted with discrete optical elements. This instrument works as a frequency discriminator, therefore, it is possible to anlyse the modulation and noise properties of semiconductor lasers with one or more sections. Single section DFB lasers, multi-section DBR and grating assisted condirectional coupler with rear sampled reflector (GCSR) lasers were characterised using the interferometer. Measuring the IM response, frequency noise and linewidth of GCSR lasers it was possible to study the detuned loading effect in these devices. This effects was quantified for the first time in this work. The dynamic characterisation of widely tunable GCSR lasers is really relevant, once very little information is available about these devices and their structure was developed recently. The GCSR laser has four sections, one gain section and three tuning sections. These devices have quasi-continous tuning range from 1520 to 1560 nm. The relative intensity noise (RIN), frequency noise and linewidth characteristics, amplitude modulation (AM) and FM responses were measured at ten different wavelength spaced by 4 nm on the tuning range. The AM response hag quasi-constant characteristics on the tuning range and the FM response is comparable or better than on ordinary distributed Bragg reflector lasers (DBR). A new technique for a parameter extraction was developed measuring AM and FM responses using a Mach-Zehnder interferometer with balanced detection. The calculated a aparameter has a maximum value in the long wavelength side and decreases in the direction of the short wavelength side. An improvement of some laser properties like frequency noise, linewidth and modulation bandwidth with the phase tuning was observed. These are characteristics of the detuned loading effect, which usually occurs in DBR lasers. This effect explains the linewidth, bandwidth and a parameter behaviour on the tuning range.