February 1, 2004
      
                  
        
  Author(s)
  Stefania  Castelletto,   Ivo P. Degiovanni,   M J. Ware,   Alan L. Migdall
 
       
            
    
    
        Many quantum computation and communication schemes require, or would significantly benefit from, true sources of single photon on-demand (SPOD). Unfortunately, such sources do not exist. It is becoming increasingly clear that coupling photons out of a SPOD