We apply the phase portrait analysis to semiconductor lasers with Auger recombination and extend the analysis to high modulation frequency &ohgr;m. On the two‐dimensional bifurcation diagram of modulation depth and modulation frequency, there are seven regions: digital pulsing regions, analog modulation region, period doubling regions, chaos regions, and one multiloop region. It is found that Auger recombination tends to suppress chaos for &ohgr;m<&ohgr;r, the relaxation frequency. However, for &ohgr;m>&ohgr;r, chaotic behavior becomes prominent. Furthermore, in the pulsing region, the maximum pulsation frequency is limited to a value around &ohgr;reven though &ohgr;mmay be twice or three times &ohgr;r. A normalized two‐dimensional bifurcation diagram defining the digital pulse region and the analog modulation region is presented for the purpose of locating the suitable region for analog and digital operation of semiconductor lasers.