Optical interconnections and integrated optoelectronic devices are expected to be promising candidates that solve the lack of interconnection bandwidth between large-scale integrated circuits (LSIs). However, although two-dimensional parallel devices such as vertical-cavity surface-emitting lasers (VCSELs) and spatial light modulators (SLMs) have massive parallelism, their capabilities are not fully utilized without appropriate way to yields high speed processing. From the viewpoint of system and algorithm, the improvement of the physical layer by optical technologies should require the reconsideration of the architectural design and algorithms so that enough performance improvements could be obtained. In this paper, we will present several of our optoelectronic parallel computing systems including a two-layer pipelined parallel system, which is called OCULAR-Il. The system uses VCSELs and phase modulation SLM for realizing free-space reconfigurable optical interconnects. The algorithmic approach is discussed including the optimal load allocation for optically interconnected systems and a novel database management algorithm. As one of the most important technological challenges, the alignment problem of optical beam is also investigated.