The effects of conical optical channel parameters on divergence of the rays radiated from an emitter plate are investigated. The optical channel is used to maximize the radiant power (flux) in a given solid angle at the exit aperture of the channel. A simulation method is presented for optimizing the channel layout, using channel gain (efficiency) as a measure of the output radiant power. The Monte Carlo method is employed to generate emitted rays, and ray tracing is performed in a 3-D fashion using each of the three reflection models, i.e., specular, diffuse, and Gaussian. The simulation results indicate that, for a given solid angle of output radiation, the channel gain attains a maximum for certain values of length, cone angle and two radii of the semiconical channel. Moreover, the channel length has only a scaling effect on channel gain when the cone angle and ratio of two radii are constant.