Novel packaging technique for laser diode arrays using film carrier

An innovative packaging technique for laser diode (LD) arrays has been developed. This technique uses a new film carrier which has high-density inner leads and microstrip lines on polyimide film. There is less mutual inductance between lines on the film carrier than with the wiring structure we conventionally use which comprises bonding wire and Al₂O₃ circuit board. This structure can reduce the electrical crosstalk between channels on the LD array. A 4-channel LD array sub-module is fabricated employing the above technique, and demonstrated. The module has good frequency characteristics over a bandwidth of 2.3 GHz. The electrical crosstalk between adjacent LDs is less than -30 dB at 1 GHz. This value is about 10 dB lower than with the conventional wiring structure