M. Akiyama

Polarisation-maintaining single-mode fibre with azimuthally inhomogeneous index profile

K. Kitayama, S. Seikai, N. Uchida, 1981 .

Transmission Characteristic Measurement of Two-Mode Optical Fiber with a Nearly Optimum Index-Profile

S. Seikai, O. Fukuda, N. Uchida, 1980 .