1. Barnoski, M. K. and Jensen, S. M. (1976) Appl. Opt.,
15(2112–5.
2. Hartog, A. H. and Gold, M. P. (1984)J Lightwave Technol.,
LT-2(76–82.
3. Neumann, E-G (1980) AEU,
34(157–60.
4. Hartog, A. H. (1983) J Lightwave Technol. LT-1, 498–509.
5. Fames, M. C. et al (1986) Electron. Lett.(
22(418–9.