The design and fabrication of an optical 2×490°hybrid based on birefringent crystals for a coherent receiver in a free−space optical communication system are presented.For the quadrature receiver,two pairs o...The design and fabrication of an optical 2×490°hybrid based on birefringent crystals for a coherent receiver in a free−space optical communication system are presented.For the quadrature receiver,two pairs of 180°phase−shift outputs are obtained and one pair has a phase difference of 90°with respect to the other.The 90°hybrid comprises two pairs of stacked birefringent plates,a phase retardation plate and an analyser birefringent plate.The testing results measured by the heterodyne method verify that the 2×4 optical 90°hybrid can work correctly and effectively.The phase compensation and further optimization schemes are also proposed.展开更多
基金by the Chinese Academy of Sciences,the National Natural Science Foundation of China under Grant No 60908029the Natural Science Foundation of Shanghai under Grant No 09ZR1435300the National High-Tech Research and Development Program of China under Grant No 2007AA01Z298.
文摘The design and fabrication of an optical 2×490°hybrid based on birefringent crystals for a coherent receiver in a free−space optical communication system are presented.For the quadrature receiver,two pairs of 180°phase−shift outputs are obtained and one pair has a phase difference of 90°with respect to the other.The 90°hybrid comprises two pairs of stacked birefringent plates,a phase retardation plate and an analyser birefringent plate.The testing results measured by the heterodyne method verify that the 2×4 optical 90°hybrid can work correctly and effectively.The phase compensation and further optimization schemes are also proposed.
