We introduce a new type of optical microconnector named "put-in microconnector-" using a planar microlens. The connector part is composed by a lens jack and fiber plug, where the lens jack is a hollow formed on a planar microlens surface, and the fiber plug is a protuberance formed on the core of an optical fiber. This concept can realize an alignment-free single mode fiber coupling. In this paper, we describe the structure and fabrication process, the optical coupling characteristics of the fabricated device, and finally, the basic analysis of optical coupling module. For the optical coupling characteristics, we measured the coupling loss and the return loss. The optical coupling loss of about 4 dB and the return loss of about 49 dB were obtained at wavelength of λ = 0.633 µm. Moreover, we have confirmed that the insertion loss of such a structure does not increase so much in comparison with that of the butt jointing. For the purpose of characterizing the optical property, the theoretical analysis was performed. We have made a software tool to estimate the optical coupling loss due to the position error. For this type of structure, the tolerance of about 15 µm for the distance between the laser and the planar microlens and 150 µm for the distance between the planar microlens and the optical fiber were estimated. Since the put-in microconnector does not require any precise alignment, it is appropriate for mass production.

At present, the widespread use of optoelectronic components is restricted by their high cost. Up to 90% of the cost of a semiconductor laser is in the packaging, with the fibre-chip alignment the major part. In this paper, an approach to low cost packaging is described, which uses an integrated mode size transformer to match the laser output to the fibre mode. This improves the alignment tolerance of the laser-fibre coupling by more than a factor of three, allowing simple passive alignment approaches to be used. It requires only minor modification to the processing of a standard buried heterostructure laser, and allows the coupling efficiency to be optimised without compromising the performance of the laser. The design of a silicon submount for passive laser-fibre alignment is described and coupling losses as low as 1.2 dB to standard cleaved single mode fibre are reported. The technology that has been developed is generic and its successful application to other optoelectronic devices such as fibre grating lasers, semiconductor optical amplifiers and laser arrays is described.