Abstract: With the concept of mode, the beam construction of semi-conductor laser and single-mode fiber has been investigated. And with general mathematical method of quantummechenics, the only ideal beam corstruction of exciting single-mode fiber has beenfound. Also, as the mode-coupling element of semi-conductor laser and single-modefiber, the feasibility and composition of CGH has been discussed. The holographiccoupling elements are obtained from CGH. The experiment result to demonstrate thecorret calculation and derivation is also shown in this paper.