ABSORPTION LOSS COEFFICIENT OF THE ACTIVE LAYER FOR 1.48-MU-M BULK AND MQW LASERS

It is shown that the absorption loss coefficient of the active layer f or 1.48-mu m bulk lasers is 66 cm(-1) which is between 45 and 107 cm(- 1) for 1.3-mu m bulk lasers and for 1.55-mu m bulk lasers, respectivel y, It is also described that the absorption loss coefficient of the ac tive layer for 1.48-mu m multiple-quantum-well (MQW) lasers is 28 cm(- 1) which is about two-fifths of that for 1.48-mu m bulk lasers, Theref ore, the high slope efficiency of the 1.48-mu m MQW lasers is attribut ed not only to the small optical confinement factor but also to the sm all absorption loss coefficient of the active layer.