An inclined coupling between laser and fiber scheme to reduce optical reflection with a spot-size converter integrated laser diode

An inclined coupling between laser and fiber (ICLF) scheme is proposed as a cost-effective means of reducing optical reflection, which causes degradation of the laser diode's relative intensity noise (RIN) characteristic. In wireless systems using sub-carrier optical transmission, it is important to achieve desirable transmission performance with low-cost optical devices to meet system requirements while keeping costs down. Optical reflection caused by optical connectors, however, prevents the attainment of such performance in optical devices. This paper describes the use of ICLF technology to reduce optical reflection. It is shown both theoretically and experimentally that the use of this technology greatly improves both the RIN and the receiver sensitivity. This technology will enable cheaper optical devices implementations in fiber-oriented wireless access systems.