1. Optical multi/demultiplexers for single-mode fiber transmission
2. Diffraction-compensated free-space WDM add-drop module with thin-film filters
3. CWDM multi/demultiplexer consisting of stacked dielectric interference filters and off-axis diffractive lenses
4. D.R. Hollars, P.T. Alexander, R.G. Cross, R. Dorn, K. Nelson, R.B. Zubeck, Miniature optical multiplexer/de-multiplexer DWDM device, United States Patent (Patent Application Publication), 2003/0206688, November 2003.
5. H. Chen, P. Gu, Y. Zhang, H. Li, X. Liu, Optical interleaver based on multi-cavity Fabry–Perot thin film filter, in: W.-S. Hu, S. Sudo, P. Kaiser (Eds.), SPIE Conference on Optical Components and Transmission Systems, vol. 4906, 2002, p. 561.