Patent ID: 7889771
Filing Date: 2011-02-15
Classification: G01S,H01S

Abstract:
1. A driving device, comprising: a light emitter generating an optical signal; a biasing circuit generating a driving signal to activate the light emitter such that the light emitter operates in a working range; a light receiver detecting the output power of the optical signal for generating a corresponding electrical signal; an automatic control system adjusting the driving signal according to the corresponding electrical signal such that the output power of the optical signal approaches a preset value; and an alternating current (AC) path coupled between the light emitter and an external signal source for receiving at least one AC modulated signal such that the light emitter generates at least one modulated optical signal, wherein the AC path receives a plurality of AC modulated signals having different frequency such that the light emitter generates different modulated optical signals, wherein the AC path comprises: a first capacitor comprising a first terminal coupled to the light emitter and a second terminal; a second capacitor comprising a first terminal coupled to the light emitter and a second terminal; a first inductor comprising a first terminal coupled to the second terminal of the first capacitor and a second terminal receiving a first AC modulated signal; and a first resistor comprising a first terminal coupled to the second terminal of the second capacitor and a second terminal receiving a second AC modulated signal.