Low operating current self‐sustained pulsation GaAlAs laser diodes with a real refractive index guided structure

We have developed a new real refractive index guided GaAlAs laser which satisfies both low operating current and low noise characteristics by self‐sustained pulsation. The structure has a planar active layer and a GaAlAs optical confinement layer which give large saturable absorber, and small internal loss. As a result, as operating current as low as 19.7 mA at an output power of 3 mW is obtained under self‐sustained pulsation, leading to a relative intensity noise level less than −135 dB/Hz.