Measurement of the linewidth enhancement factor in DFB lasers using a high-resolution optical spectrum analyzer

Linewidth enhancement factor (also know as chirp parameter is calculated for two distributed feedback lasers using the linewidth asymptotic behavior predicted by Schawles-Townes and Henry. A high-resolution optical spectrum analyzer (BOSA) is used to measure power and linewidth. Comparison with widely accepted network analyzer method is performed with very good agreement.