| 摘要 |
PURPOSE:To apply a bias voltage to the absorption region diode of a bistable semiconductor laser automatically and eliminate a bias voltage source and obtain a small size bistable semiconductor laser drive circuit with excellent characteristics by a method wherein a resistor is connected to both the ends of the absorption region diode or both the ends of the diode are short-circuited. CONSTITUTION:A bias resistor 6 is connected to an absorption region diode 3 instead of a conventional bias voltage source. A bias voltage Vb applied to the absorption region diode 3 is expressed by a formula Vbapprox.=RA/Ri+RA.Eg, wherein Eg denotes the forbidden band width (eV) of an active layer, RA denotes the resistance of the bias resistor 6 and Ri denotes the resistance of an isolation resistor 4. For instance, in the case of a GaAs bistable laser, as Eg=1.4eV, if Ri=2kOMEGA and RA=500OMEGA, Vb=0.4V is obtained. By varying the resistance RA between 0 and 2kOMEGA, the bias voltage Vb between 0 and 0.7V can be obtained. Thus, by connecting the bias resistor 6 to the absorption region diode 3, the arbitrary bias voltage between 0 and 0.9Eg (V) can be applied. |
