Effect of fixed emission wavelength on threshold current of InGaAsP semiconductor laser diodes

The authors demonstrate and quantify the extent to which a reduced variation of laser diode threshold current with temperature can be achieved by fixing lasing wavelength on the long wavelength side of the room temperature gain peak. This enhancement (T₀=92 K) occurs at the expense of increased threshold current at low temperatures. Fixing the lasing wavelength on the short wavelength side of the room temperature gain peak to reduce dynamic spectral broadening occurring at high modulation rates leads to reduced T₀ (=30 K) in comparison to Fabry-Perot laser diodes T₀ (=42 K) made from the same material.