We present different configurations for a compact free-space optical interconnection module by combining two radial gradientrefractive- index lenses and/or two arrays of refractive microlenses. Based on our findings with ray tracing and radiometric analysis, we discuss how we have selected the proper optical system configurations and how we have chosen the different design parameters to optimally accommodate different types of optoelectronic emitters such as LEDs, microcavity LEDs, and vertical-cavity surface-emitting lasers. We focused on maximizing optical coupling efficiencies and misalignment tolerances while minimizing interchannel crosstalk.