Ex Parte Schrodinger - Page 5



              Appeal No. 2007-0400                                                                                      
              Application 10/788,054                                                                                    

              applicant can overcome a rejection [for obviousness] by showing insufficient                              
              evidence of prima facie obviousness or by rebutting the prima facie case with                             
              evidence of secondary indicia of nonobviousness.”).                                                       

                                                     ANALYSIS                                                           
                     The reference discloses a reconfigurable DWDM (Dense Wavelength                                    
              Division Multiplexing) optical transmitter that employs “n” active lasers and “k”                         
              spare lasers (col. 5, ll. 46-47) and typically employs two spare lasers                                   
              for every eight active lasers (col. 13, ll. 7-8).                                                         
                     Referring to Figure 2, the transmitter employs a common gas cell 208                               
              comprising a gas of a known spectral line frequency and one etalon (also called the                       
              grid generator) 212 to establish a frequency grid for “n” lasers 202 and therefore                        
              “n” channels (col. 7, ll. 15-23).  More particularly, the etalon generates a comb of                      
              equally spaced laser wavelengths (col. 5, ll. 50-52; Fig. 4), also referred to as                         
              “successive fringes” (col. 7, ll. 22-23).  A reference frequency control loop 228                         
              initializes and tunes each laser to the reference spectral frequency derived from gas                     
              cell 208 (col. 7, ll. 23-25).  A grid positioning control loop 226 sequentially tunes                     
              each laser 202 in the bank to a respective “fringe” of the frequencies of grid                            
              generator 212 (col. 7, ll. 20-28).  The optical paths of all of the lasers, including the                 
              spare lasers, are always connected to the output of transmitter module 225 (col. 7,                       
              ll. 59-63).                                                                                               
                     As shown in Figure 1, which depicts only one of the lasers, a “Detector 1”                         
              (314) provides the control input for the reference frequency control loop 228                             
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