AMENDMENT
      NO. 1 TO 

    


    STOCK
      PURCHASE AGREEMENT

    


    This
      Amendment No. 1 (this “Amendment”),
      dated
      October 22, 2008, to the Stock Purchase Agreement (as defined below) is made
      by
      and among Vector Intersect Security Acquisition Corporation, a Delaware
      corporation (“Parent”),
      Cyalume Acquisition Corp., a Delaware corporation (“Purchaser”), Cyalume
      Technologies, Inc., a Delaware corporation (the “Company”),
      and
      GMS Acquisition Partners Holdings, LLC (“Seller”).
      Any
      capitalized term not defined herein shall have the meaning for such term
      specified in the Stock Purchase Agreement.

    


    WHEREAS,
      Parent,
      Purchaser, the Company and Seller entered into a Stock Purchase Agreement dated
      February 14, 2008, (the “Stock
      Purchase Agreement”);
      and

    


    WHEREAS,
      Sections
      2.3(c)(ii) and (iii) of the Stock Purchase Agreement set forth certain terms
      governing the payment of the Estimated Purchase Price to or for the benefit
      of
      the Members who hold Series A Preferred Units of Seller as of the Closing Date;
      and 

    


    WHEREAS,
      Parent,
      Purchaser, the Company and the Sellers desire to amend the terms of such
      payments so that the Members holding Series A Preferred Units of Seller shall
      receive and Parent shall issue additional Parent Common Stock in lieu of an
      amount in cash equal to $10,000,000.

    


    NOW
      THEREFORE, in
      consideration of the foregoing and the representations, warranties, covenants
      and agreements herein contained and other good and valuable consideration,
      the
      receipt and sufficiency of which is hereby acknowledged, the parties hereto
      hereby agree as follows:

    


    1. Section
      2.3(c)(ii) of the Stock Purchase Agreement is hereby amended by deleting the
      number $15,000,000 and replacing
      it with the number $5,000,000.

    


    2. Section
      2.3(c)(iii) of the Stock Purchase Agreement is hereby amended by deleting the
      number $15,000,000 and replacing it with the number $5,000,000.

    


    3. The
      Amendment set forth herein is limited precisely as written and shall not be
      deemed to be an amendment of any other term or condition of the Stock Purchase
      Agreement or any of the documents referred to therein. For the avoidance of
      doubt, the purpose of this Amendment is to change the form of payment with
      respect to a portion of the amount payable to the Members holding Series A
      Preferred Units of Seller, and not to change the aggregate Purchase Price
      payable under the Stock Purchase Agreement. Whenever the Stock Purchase
      Agreement is referred to in any agreement, document or instrument, such
      reference shall be to the Stock Purchase Agreement as amended hereby. Except
      as
      expressly amended hereby, the terms and conditions of the Stock Purchase
      Agreement shall continue in full force and effect.

    


    4. This
      Amendment may be signed in any number of counterparts, each of which shall
      be an
      original and all of which shall be deemed to be one and the same instrument,
      with the same effect as if the signatures thereto and hereto were upon the
      same
      instrument. A facsimile signature shall be deemed to be an original signature
      for purposes of this Amendment.

     

    5. This
      Amendment is intended to be in full compliance with the requirements for an
      Amendment to the Stock Purchase Agreement as required by Section 14.2 of the
      Stock Purchase Agreement, and every defect in fulfilling such requirements
      for
      an effective amendment to the Stock Purchase Agreement is hereby ratified,
      intentionally waived and relinquished by all parties hereto. 

     

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

     

    IN
      WITNESS WHEREOF,
      the
      parties hereto have duly executed this Amendment No.1 to the Stock Purchase
      Agreement as of the day and year first above written.

     

    

      
        	 	
                VECTOR
                  INTERSECT ACQUISITION CORP.

              	 
	 	 	 	 
	 	 	 	 
	 	
                By: 
                  

              	
                /s/
                  Yaron Eitan

              	 
	 	 	
                Name:
                  Yaron Eitan

              	 
	 	 	
                Title:
                  Chief Executive Officer 

              	 
	 	 	 	 
	 	
                CYALUME
                  ACQUISITION CORP.

              	 
	 	 	 	 
	 	 	 	 
	 	
                By: 
                  

              	
                /s/
                  Yaron Eitan

              	 
	 	 	
                Name:
                  Yaron Eitan

              	 
	 	 	
                Title:
                  Director 

              	 
	 	 	 	 
	 	
                CYALUME
                  TECHNOLOGIES, INC.

              	 
	 	 	 	 
	 	 	 	 
	 	
                By: 
                  

              	
                /s/
                  Michael Bielonko

              	 
	 	 	
                Name:
                  Michael Bielonko

              	 
	 	 	
                Title:
                  Chief Financial Officer

              	 
	 	 	 	 
	 	
                GMS
                  ACQUISITION PARTNERS HOLDINGS, LLC

              	 
	 	 	 	 
	 	 	 	 
	 	
                By: 
                  

              	
                /s/
                  Frank R. Kline

              	 
	 	 	
                Name:
                  Frank R. Kline

              	 
	 	 	
                Title:
                  Director