A Simple Model to Measure Linewidth Enhancement Factor (α) for Multi-wavelengths Semiconductor Laser

A novel and simple model is proposed for the measurement of the linewidth enhancement factor (LEF) {\alpha} of multiwavelengths semiconductor laser. It is based on the suppression characteristics of an arbitrary mode while other modes are optically injection locked individually. The proposed model can be used to measure {\alpha} value of individual modes of multi-wavelengths laser with large mode spacing. As a proof of the concept, the model is used to experimentally measure {\alpha} of a mode of a slotted Fabry- P\'erot laser source.