Title : 
Design Principles for Higher (Prime) Order Composite Directional Couplers
         
        
        
        
        
        
        
        
            Abstract : 
The theoretical construction of ideal (lossless) 3 times 3, 4 times 4, and 5 times 5 dimensional directional couplers from 2 times 2 directional couplers is demonstrated. Such devices could be fabricated as planar waveguide circuit elements.
         
        
            Keywords : 
optical directional couplers; optical planar waveguides; higher order composite directional couplers; ideal lossless directional couplers; planar waveguide circuit element; prime directional coupler; 5$,times,$ 5; Directional couplers; lossless; prime; single mode;
         
        
        
            Journal_Title : 
Photonics Technology Letters, IEEE
         
        
        
        
        
            DOI : 
10.1109/LPT.2009.2024431