A GaAs Semiconductor Laser Operating At 870 Nm Has A Cavity Length Of 50um. The Two Cavity Mirrors Are Coated And Have Reflectivity Of R1 = 1.0 And R2 = 60%, Respectively. The GaAs Material Has A Loss Coefficient At Normal Temperature Of Gamma = 10 Cm^-1. The Threshold Gain Coefficient Of The Semiconductor Laser Is: 65 (5 Points) (A) 81cm^-1 O (B) 61 Cm

 

1. A GaAs semiconductor laser operating at 870 nm has a cavity length of 50m. The two cavity mirrors are coated and have reflectivity of R1 = 1.0 and R2 = 60%, respectively. The GaAs material has a loss coefficient at normal temperature of gamma = 10 cm^-1. The threshold gain coefficient of the semiconductor laser is: (5 Points) (a) 81cm^-1 (b) 61 cm^-1 (c) 71cm^-1 (d) 51cm-1