Third Amendment to Purchase and Sale Agreement and Preliminary Escrow Instructions
      dated February 27, 2005, with Pulte Home Corporation.


    Exhibit
      10.8.3

     

    THIRD
      AMENDMENT TO

    PURCHASE
      AND SALE AGREEMENT

    AND
      PRELIMINARY ESCROW INSTRUCTIONS

    [Portion
      of DiCon Fiberoptics Inc. Land, Regatta Boulevard, Richmond,
      California]

    


    This
      Third Amendment to Purchase and Sale Agreement and Preliminary Escrow
      Instructions (the “Third
      Amendment”)
      is
      entered into as of February 27, 2005, between DICON FIBEROPTICS, INC., a
      California corporation (“Seller”)
      and
      PULTE HOME CORPORATION, a Michigan corporation (“Buyer”).

    


    RECITALS

    


    
      	 	
              A.

            	
              Seller
                and Buyer entered into a Purchase and Sale Agreement and Preliminary
                Escrow Instructions as of February 27, 2004, a First Amendment to
                Purchase
                and Sale Agreement and Preliminary Escrow Instructions as of March
                1,
                2004, and a Second Amendment to Purchase and Sale Agreement and
                Preliminary Escrow Instructions as of April 29, 2004 (collectively,
                the
                “Agreement”).

            


    

    


    
      
        	 	
                B.

              	
                Seller
                  and Buyer desire to amend and restate certain provision of the
                  Agreement
                  as provided in this Second
                  Amendment.

              


      

       

    

    The
      parties agree as follows:

    


    AGREEMENT

    


    
      	 	
              1.

            	
              Section
                13.2.1 of the Agreement is hereby amended and restated in its entirety
                to
                read as follows:

            


    

    


    
      	
            	“13.2.1	
              Extension
                of Closing Date if City has not approved the Tentative Map.
                Buyer may elect to extend the Closing Date as provided and subject
                to the
                conditions precedent in this Section
                13.2.1.

            


    

    


    1st
      Extension: If the City has not approved the Tentative Map on or before the
      date
      of February 28, 2005, Buyer may extend the Closing Date to the date of March
      30,
      2005.

    


    2nd
      Extension: If Buyer has extended the Closing Date as provided under the
      1st
      extension and if the City has not approved the Tentative Map on or before the
      date of March 30, 2005, Buyer may extend the Closing Date to the date of April
      29, 2005.

    


    3rd
      Extension: If Buyer has extended the Closing Date as provided under the
      2nd
      extension and if the City has not approved the Tentative Map on or before the
      date of April 29, 2005, Buyer may extend the Closing Date to the date of May
      31,
      2005.

    


    4th
      Extension: If Buyer has extended the Closing Date as provided under the
      3rd
      extension and if the City has not approved the Tentative Map on or before the
      date May 31, 2005, Buyer may extend the Closing Date to the date of June 30,
      2005.

    


    5th
      Extension: If Buyer has extended the Closing Date as provided under the
      4th
      extension and if the City has not approved the Tentative Map on or before the
      date of June 30, 2005, Buyer may extend the Closing Date to the date of July
      29,
      2005.

    


    6th
      Extension: If Buyer has extended the Closing Date as provided under the
      5th
      extension and if the City has not approved the Tentative Map on or before the
      date of July 29, 2005, Buyer may extend the Closing Date to the date of August
      29, 2005.

    


    Each
      of
      the 1st,
      2nd,
      and
      3rd
      extensions is subject to the conditions precedent that, on or before the Closing
      Date as in effect prior to each such extension (a) Seller and Escrow Agent
      shall
      each have received from Buyer a written notice of Buyer’s election to extend the
      Closing Date, and (b) Seller shall have received from Buyer by wire transfer
      an
      extension payment in the amount of Twenty Five Thousand Dollars ($25,000.00).
      

    


    Each
      of
      the 4th,
      5th
      and
      6th
      extensions is subject to the conditions precedent that, on or before the Closing
      Date as in effect prior to each such extension (a) Seller and Escrow Agent
      shall
      each have received from Buyer a written notice of Buyer’s election to extend the
      Closing Date, (b) Seller shall have received from Buyer by wire transfer an
      extension payment in the amount of Fifty Thousand Dollars ($50,000.00), and
      (c)
      Seller shall have received from Buyer by wire transfer an extension deposit
      in
      the amount of One Hundred Thousand Dollars ($100,000.00). 

    


    The
      extension payments under this Section 13.2.1 are not applicable to the Purchase
      Price. The extension deposits under this Section 13.2.1 actually received by
      Seller shall be applied to the Purchase Price on the Close of Escrow. The
      extension payments and the extension deposits are non-refundable under any
      and
      all circumstances including, but not limited to, any termination of Buyer’s
      obligation to purchase and Seller’s obligation to sell the Purchase Property
      under this Agreement.

    


    
      	 	
              2.

            	
              Section
                22 of the Agreement is hereby amended to change the address for notices
                to
                Buyer as follows:

            


    

    


    PULTE
      HOME CORPORATION

    6210
      Stoneridge Mall Road, 5th
      Floor

    Pleasanton,
      CA 94588

    Attn:
      Steve Kalmbach

    Fax
      No.:
      (925) 249-4373

     

    
      	 	
              3.

            	
              The
                parties hereby affirm the Purchase and Sale Agreement and Preliminary
                Escrow Instructions dated as of February 27, 2004, the First Amendment
                to
                Purchase and Sale Agreement and Preliminary Escrow Instructions dated
                as
                of March 1, 2004, and the Second Amendment to Purchase and Sale Agreement
                and Preliminary Escrow Instructions dated as of April 29,
                2004.

            


    

     

    
      
        	 	
                4.

              	
                
                  Except
                    as amended and restated by this Third Amendment, all terms, conditions
                    and
                    provisions of the Agreement shall remain in full force and
                    effect.

                

              


      


      
        	 	
                5.

              	
                
                  This
                    Third Amendment may be executed by the different parties hereto
                    on
                    separate counterparts each of which, when so executed, shall
                    be deemed an
                    original but all such counterparts shall constitute but one and
                    the same
                    agreement.

                

              


      

    

    
IN
      WITNESS HEREOF,
      the
      parties hereto have executed this Third Amendment as of the date first above
      written.

    


    
      	
              Seller:

            	
              Buyer:

            
	 	 
	
              DICON
                FIBEROPTICS, INC., 

            	
              PULTE
                HOME CORPORATION

            
	
              a
                California corporation

            	
              a
                Michigan corporation

            
	 	 
	
              By: /s/
                Ho-Shang Lee

            	
              By:
                /s/ Steven Kalmbach

            
	
              Name:
                 Ho-Shang
                Lee, Ph.D.

            	
              Name:
                 Steven
                Kalmbach

            
	
              Its:
                President & CEO

            	
              Its:
                 Division
                President

            


    

     

    Acceptance
      by Escrow Holder

    


    CHICAGO
      TITLE COMPANY hereby acknowledges that it has received originally executed
      counterparts or a fully executed original of the foregoing Third Amendment
      to
      Purchase and Sale Agreement and Preliminary Escrow Instructions and agrees
      to
      act as Escrow Agent thereunder and to be bound by and perform the terms thereof
      as such terms apply to Escrow Agent.

     

    


    CHICAGO
      TITLE COMPANY

    


    By:
       /s/
      Laurie J. Edwards  

    


    Name:
       Laurie
      J.
      Edwards

    Its:
       Assistant
      Vice President

    Date
      of
      Execution:  5-3-05