The influence of the dip angle on light distribution inside tissue was investigated. Based on the investigation, a LOT system with condensed dip-angle (cdaLOT) over the whole detection range was developed. A new method for correcting the deflection-angle of galvanometer mirrors was also proposed. A fast image reconstruction algorithm for LOT was also developed based on the virtual-source diffusion approximation and GPU. Light path simulation showed that the developed cdaLOT system decreased the dip angle of the incident light to 1/2 of that of the traditional LOT system. The relative deviation of the measured data to MC results was about 18% for cdaLOT while that for traditional LOT was as large as 38%. Reconstructed images showed that the reconstructed absorption coefficient, and the position and shape of the inhomogeneity coincided with the real target.