Derivation of the Spectral Width of a 0.8µm AlGaAs Laser Considering 1/f Noise

The spectral profile of a CSP-type 0.8 µm AlGaAs laser and its spectral width (FWHM) were estimated from experimental results on the lasers FM noise at room temperature. The power-independent spectral width was also derived from the recently-reported power-independent 1/f noise. The result was 2.0 MHz, which agrees well with previous experimental results. The power-dependent width Δν was also derived as 2.0 MHz<Δν≦8.8 MHz for 0<(I/I th-1)-1≦7, where I and I th represent the injection current and its threshold value, respectively.