[1] Brannon P J. Improved method of measuring optical waveguide propagation losses. Appl. Opt., 1986, 25(20):3596～3598

[2] Haruna M, Segawa Y, Nishihara H. Nondestructive and simple method of optical-waveguide loss measurement with optimisation of end-fire coupling. Electron. Lett., 1992, 28(17):1612～1613

[3] Hunsperger R G. Integrated optics: theory and technology. New York: Springer-Verlag, 1982. 83～85