Coupling efficiency between a laser diode and a conically lensed single mode fibre

Both the far field intensity pattern (FFIP) of a laser diode and the fibre electric field profile play an important role in determining the coupling efficiency between laser diodes (LDs) and optical fibres. In this paper, we would present a model for the FFIP of laser diodes, which is based on the non-linear regression technique. The model reflects a more accurate representation of the far field intensity pattern compared to the Gaussian model, thus enabling a better estimation of the spot size of the LD. We would also present a theoretical analysis of coupling efficiency between a laser diode and a conically lensed fibre taking into account the effect of multiple reflection from the lens surface