Exhibit 4.6 THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE OF THIS WARRANT HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, AND MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED OR EXERCISED UNLESS AND UNTIL SAID SECURITY IS REGISTERED UNDER SUCH ACT OR AN OPINION OF COUNSEL SATISFACTORY TO THE COMPANY IS OBTAINED TO THE EFFECT THAT SUCH REGISTRATION IS NOT REQUIRED. THIS WARRANT AND THE SHARES OF COMMON STOCK ISSUABLE UPON EXERCISE OF THIS WARRANT ARE SUBJECT TO THE RESTRICTIONS ON TRANSFER SET FORTH IN SECTIONS 4 AND 10 OF THIS WARRANT. Ladenburg Thalmann Warrant No. 1 Number of Shares: 84,083 (subject to adjustment) Date of Issuance: June 21, 2000 APA OPTICS, INC. Common Stock Purchase Warrant (Void after June 20, 2003) APA Optics, Inc., a Minnesota corporation (the "Company"), for value received, hereby certifies that Ladenburg Thalmann & Co. Inc., or its registered assigns (the "Registered Holder"), is entitled, subject to the terms and conditions set forth below, to purchase from the Company, at any time or from time to time on or after the date of issuance and on or before 5:00 p.m. (Eastern time) on June 20, 2003, 84,083 shares of Common Stock, $.01 par value per share, of the Company, at a purchase price of $17.8395 per share. The shares purchasable upon exercise of this Warrant, and the purchase price per share, each as adjusted from time to time pursuant to the provisions of this Warrant, are hereinafter referred to as the "Warrant Shares" and the "Purchase Price," respectively. 1. Exercise. (a) This Warrant may be exercised by the Registered Holder, in whole or in part, by surrendering this Warrant, with the purchase form appended hereto as Exhibit I duly executed by the Registered Holder or by the Registered Holder's duly authorized attorney, at the principal office of the Company, or at such other office or agency as the Company may designate, accompanied by payment in full, in lawful money of the United States, of the Purchase Price payable in respect of the number of Warrant Shares purchased upon such exercise. (b) The Registered Holder may, at its option, elect to pay some or all of the Purchase Price payable upon an exercise of this Warrant by cancelling a portion of this Warrant. If the Registered Holder wishes to exercise this Warrant by this method, the number of Warrant Shares purchasable (which shall in no event exceed the total number of Warrant Shares purchasable under this Warrant as set forth above, subject to adjustment under Section 2 of this Warrant) shall be determined as follows: X = Y [(A-B) / A] X = the number of Warrant Shares to be issued to the Holder. Y = the number of Warrant Shares with respect to which this Warrant is being exercised. A = the Fair Market Value of one share of Common Stock. B = the Purchase Price of one share of Common Stock. The Fair Market Value per share of Common Stock shall be determined as follows: (i) If the Common Stock is listed on a national securities exchange, the Nasdaq National Market or another nationally recognized trading system (including, without limitation, the OTC Bulletin Board and, if the average daily trading volume for the preceding 10 days has been at least 100,000 shares, the Pink Sheets) as of the Exercise Date, the Fair Market Value per share of Common Stock shall be deemed to be the average of the high and low reported sale prices per share of Common Stock thereon on the trading day immediately preceding the Exercise Date (provided that if no such price is reported on such day, the Fair Market Value per share of Common Stock shall be determined pursuant to clause (ii)). (ii) If the Common Stock is not listed on a national securities exchange, the Nasdaq National Market or another nationally recognized trading system as of the Exercise Date, the Fair Market Value per share of Common Stock shall be deemed to be the amount most recently determined by the Board of Directors to represent the fair market value per share of the Common Stock (including without limitation a determination for purposes of granting Common Stock options or issuing Common Stock under an employee benefit plan of the Company); and, upon request of the Registered Holder, the Board of Directors (or a representative thereof) shall promptly notify the Registered Holder of the Fair Market Value per share of Common Stock. Notwithstanding the foregoing, if the Board of Directors has not made such a determination within the three-month period prior to the Exercise Date, then (A) the Board of Directors shall make a determination of the Fair Market Value per share of the Common Stock within 15 days of a request by the Registered Holder that it do so, and (B) the exercise of this Warrant pursuant to this subsection 1(b) shall be delayed until such determination is made. (c) Each exercise of this Warrant shall be deemed to have been effected immediately prior to the close of business on the day on which this Warrant shall have been surrendered to the Company as provided in subsection 1(a) above accompanied by payment in full of the Purchase Price (the "Exercise Date"). At such time, the person or persons in whose name or names any certificates for Warrant Shares shall be issuable upon such exercise as provided in subsection 1(d) below shall be deemed to have become the holder or holders of record of the Warrant Shares represented by such certificates. 2 (d) As soon as practicable after the exercise of this Warrant in full or in part, and in any event within 5 business days thereafter, the Company, at its expense, will cause to be issued in the name of, and delivered to, the Registered Holder, or as such Holder (upon payment by such Holder of any applicable transfer taxes) may direct: (i) a certificate or certificates for the number of full Warrant Shares to which the Registered Holder shall be entitled upon such exercise plus, in lieu of any fractional share to which the Registered Holder would otherwise be entitled, cash in an amount determined pursuant to Section 3 hereof; and (ii) in case such exercise is in part only, a new warrant or warrants (dated the date hereof) of like tenor, calling in the aggregate on the face or faces thereof for the number of remaining Warrant Shares (without giving effect to any adjustment therein). 2. Adjustments. (a) Adjustment for Stock Splits and Combinations. If the Company shall at any time or from time to time after the date on which this Warrant was first issued (the "Original Issue Date") effect a subdivision of the outstanding Common Stock, the Purchase Price then in effect immediately before that subdivision shall be proportionately decreased. If the Company shall at any time or from time to time after the Original Issue Date combine the outstanding shares of Common Stock, the Purchase Price then in effect immediately before the combination shall be proportionately increased. Any adjustment under this paragraph shall become effective at the close of business on the date the subdivision or combination becomes effective. (b) Adjustment for Certain Dividends and Distributions. In the event the Company at any time, or from time to time after the Original Issue Date shall make or issue, or fix a record date for the determination of holders of Common Stock entitled to receive, a dividend or other distribution payable in additional shares of Common Stock, then and in each such event the Purchase Price then in effect immediately before such event shall be decreased as of the time of such issuance or, in the event such a record date shall have been fixed, as of the close of business on such record date, by multiplying the Purchase Price then in effect by a fraction: (1) the numerator of which shall be the total number of shares of Common Stock issued and outstanding immediately prior to the time of such issuance or the close of business on such record date, and (2) the denominator of which shall be the total number of shares of Common Stock issued and outstanding immediately prior to the time of such issuance or the close of business on such record date plus the number of shares of Common Stock issuable in payment of such dividend or distribution; provided, however, if such record date shall have been fixed and such dividend is not fully paid or if such distribution is not fully made on the date fixed therefor, the Purchase Price shall be recomputed accordingly as of the close of business on such record date and thereafter the 3 Purchase Price shall be adjusted pursuant to this paragraph as of the time of actual payment of such dividends or distributions. (c) Adjustment in Number of Warrant Shares. When any adjustment is required to be made in the Purchase Price pursuant to subsections 2(a) or 2(b), the number of Warrant Shares purchasable upon the exercise of this Warrant shall be changed to the number determined by dividing (i) an amount equal to the number of shares issuable upon the exercise of this Warrant immediately prior to such adjustment, multiplied by the Purchase Price in effect immediately prior to such adjustment, by (ii) the Purchase Price in effect immediately after such adjustment. (d) Adjustment for Mergers or Reorganizations, etc. If there shall occur any reorganization, recapitalization, consolidation or merger involving the Company in which the Common Stock is converted into or exchanged for securities, cash or other property (other than a transaction covered by subsections 2(a) or 2(b)), then, following any such reorganization, recapitalization, consolidation or merger, the Registered Holder shall receive upon exercise hereof the kind and amount of securities, cash or other property which the Registered Holder would have been entitled to receive if, immediately prior to such reorganization, recapitalization, consolidation or merger, the Registered Holder had held the number of shares of Common Stock subject to this Warrant ("Substituted Property"). In the event that the Company is not the acquiring or surviving entity in such transaction, then the acquiror or survivor, at its option, may repurchase this Warrant, effective not later than the effective date of the acquisition, merger, or other transaction, by issuing to the Holder the Substituted Property which would have been issuable if the Holder had chosen to exercise this Warrant in full using the exercise method described in Section 1(b), above, at the time of the repurchase. (e) Certificate as to Adjustments. Upon the occurrence of each adjustment or readjustment of the Purchase Price pursuant to this Section 2, the Company at its expense shall promptly compute such adjustment or readjustment in accordance with the terms hereof and furnish to the Registered Holder a certificate setting forth such adjustment or readjustment (including the kind and amount of securities, cash or other property for which this Warrant shall be exercisable and the Purchase Price) and showing in detail the facts upon which such adjustment or readjustment is based. The Company shall, upon the written request at any time of the Registered Holder, furnish or cause to be furnished to the Registered Holder a certificate setting forth (i) the Purchase Price then in effect and (ii) the number of shares of Common Stock and the amount, if any, of other securities, cash or property which then would be received upon the exercise of this Warrant. 3. Fractional Shares. The Company shall not be required upon the exercise of this Warrant to issue any fractional shares, but shall make an adjustment therefor in cash on the basis of the Fair Market Value per share of Common Stock, as determined pursuant to subsection 1(b) above. 4. Requirements for Transfer. (a) This Warrant and the Warrant Shares shall not be sold or transferred unless either (i) they first shall have been registered under the Securities Act of 1933, as 4 amended (the "Act"), or (ii) the Company first shall have been furnished with an opinion of legal counsel, reasonably satisfactory to the Company, to the effect that such sale or transfer is exempt from the registration requirements of the Act. (b) Notwithstanding the foregoing, no registration or opinion of counsel shall be required for (i) a transfer by a Registered Holder which is a corporation to a wholly owned subsidiary of such corporation, a transfer by a Registered Holder which is a partnership to a partner of such partnership or a retired partner of such partnership or to the estate of any such partner or retired partner, a transfer by a Registered Holder which is a limited liability company to a member of such limited liability company or a retired member or to the estate of any such member or retired member, or a transfer by a Registered Holder which is a member of the National Association of Securities Dealers (the "NASD") to an officer of the Registered Holder as permitted by NASD rules, provided that the transferee in each case agrees in writing to be subject to the terms of this Section 4, or (ii) a transfer made in accordance with Rule 144 under the Act. (c) Each certificate representing Warrant Shares shall bear a legend substantially in the following form: "The securities represented by this certificate have not been registered under the Securities Act of 1933, as amended, and may not be offered, sold or otherwise transferred, pledged or hypothecated unless and until such securities are registered under such Act or an opinion of counsel satisfactory to the Company is obtained to the effect that such registration is not required." The foregoing legend shall be removed from the certificates representing any Warrant Shares, at the request of the holder thereof, at such time as they become eligible for resale pursuant to Rule 144(k) under the Act. 5. No Impairment. The Company will not, by amendment of its charter or through any reorganization, transfer of assets, consolidation, merger, dissolution, issue or sale of securities or any other voluntary action, avoid or seek to avoid the observance or performance of any of the terms of this Warrant, but will at all times in good faith assist in the carrying out of all such terms and in the taking of all such action as may be necessary or appropriate in order to protect the rights of the holder of this Warrant against impairment. 6. Notices of Record Date, etc. In the event: (a) the Company shall take a record of the holders of its Common Stock (or other stock or securities at the time deliverable upon the exercise of this Warrant) for the purpose of entitling or enabling them to receive any dividend or other distribution, or to receive any right to subscribe for or purchase any shares of stock of any class or any other securities, or to receive any other right; or (b) of any capital reorganization of the Company, any reclassification of the Common Stock of the Company, any consolidation or merger of the Company with or into another corporation (other than a consolidation or merger in which the Company is the surviving 5 entity and its Common Stock is not converted into or exchanged for any other securities or property), or any transfer of all or substantially all of the assets of the Company; or (c) of the voluntary or involuntary dissolution, liquidation or winding-up of the Company, then, and in each such case, the Company will mail or cause to be mailed to the Registered Holder a notice specifying, as the case may be, (i) the record date for such dividend, distribution or right, and the amount and character of such dividend, distribution or right, or (ii) the effective date on which such reorganization, reclassification, consolidation, merger, transfer, dissolution, liquidation or winding-up is to take place, and the time, if any is to be fixed, as of which the holders of record of Common Stock (or such other stock or securities at the time deliverable upon the exercise of this Warrant) shall be entitled to exchange their shares of Common Stock (or such other stock or securities) for securities or other property deliverable upon such reorganization, reclassification, consolidation, merger, transfer, dissolution, liquidation or winding-up. Such notice shall be mailed at least ten days prior to the record date or effective date for the event specified in such notice. Failure by the Company to give timely notice, as specified above, shall not invalidate any action taken by the Board of Directors or the stockholders in connection with the matter to which the record date relates. 7. Reservation of Stock. The Company will at all times reserve and keep available, solely for issuance and delivery upon the exercise of this Warrant, such number of Warrant Shares and other securities, cash and/or property, as from time to time shall be issuable upon the exercise of this Warrant. 8. Exchange of Warrants. Upon the surrender of this Warrant by the Registered Holder, properly endorsed, to the Company at the principal office of the Company, the Company will, subject to the provisions of Section 4 hereof, issue and deliver to or upon the order of such Holder, at the Company's expense, a new Warrant or Warrants of like tenor, in the name of the Registered Holder or as the Registered Holder (upon payment by the Registered Holder of any applicable transfer taxes) may direct, calling in the aggregate on the face or faces thereof for the number of shares of Common Stock (or other securities, cash and/or property) then issuable upon exercise of this Warrant. 9. Replacement of Warrants. Upon receipt of evidence reasonably satisfactory to the Company of the loss, theft, destruction or mutilation of this Warrant and (in the case of loss, theft or destruction) upon delivery of an indemnity agreement (with surety if reasonably required) in an amount reasonably satisfactory to the Company, or (in the case of mutilation) upon surrender and cancellation of this Warrant, the Company will issue, in lieu thereof, a new Warrant of like tenor. 6 10. Transfers, etc. (a) The Company will maintain a register containing the name and address of the Registered Holder of this Warrant. The Registered Holder may change its or his address as shown on the warrant register by written notice to the Company requesting such change. (b) Subject to the provisions of Section 4 hereof, this Warrant and all rights hereunder are transferable, in whole or in part, upon surrender of this Warrant with a properly executed assignment (in the form of Exhibit II hereto) at the principal office of the Company. (c) Until any transfer of this Warrant is made in the warrant register, the Company may treat the Registered Holder as the absolute owner hereof for all purposes; provided, however, that if and when this Warrant is properly assigned in blank, the Company may (but shall not be obligated to) treat the bearer hereof as the absolute owner hereof for all purposes, notwithstanding any notice to the contrary. 11. Representations of the Registered Holder. The Registered Holder of this Warrant represents and warrants to the Company as follows: (a) Investment. The Registered Holder is acquiring this Warrant and the Warrant Shares issuable upon the exercise of this Warrant, for its own account for investment and not with a view to, or for sale in connection with, any distribution thereof, nor with any present intention of distributing or selling the same, except as otherwise may be permitted under applicable securities laws. (b) Authority. The Registered Holder has full power and authority to enter into and to perform this Warrant in accordance with its terms. The Registered Holder has not been organized, reorganized or recapitalized specifically for the purpose of investing in the Company. (c) Accredited Investor. The Registered Holder is an Accredited Investor within the definition set forth in Rule 501(a) promulgated under the Securities Act. 12. Mailing of Notices, etc. All notices and other communications from the Company to the Registered Holder shall be mailed by first-class certified or registered mail, postage prepaid, to the address last furnished to the Company in writing by the Registered Holder. All notices and other communications from the Registered Holder or in connection herewith to the Company shall be mailed by first-class certified or registered mail, postage prepaid, to the Company at its principal office set forth below. If the Company should at any time change the location of its principal office to a place other than as set forth below, it shall give prompt written notice to the Registered Holder and thereafter all references in this Warrant to the location of its principal office at the particular time shall be as so specified in such notice. 13. No Rights as Stockholder. Until the exercise of this Warrant, the Registered Holder shall not have or exercise any rights by virtue hereof as a stockholder of the Company. Notwithstanding the foregoing, in the event (i) the Company effects a split of the Common Stock by means of a stock dividend and the Purchase Price of and the number of Warrant Shares are adjusted as of the date of the distribution of the dividend (rather than as of the record date for 7 such dividend), and (ii) the Registered Holder exercises this Warrant between the record date and the distribution date for such stock dividend, the Registered Holder shall be entitled to receive, on the distribution date, the stock dividend with respect to the shares of Common Stock acquired upon such exercise, notwithstanding the fact that such shares were not outstanding as of the close of business on the record date for such stock dividend. 14. Change or Waiver. Any term of this Warrant may be changed or waived only by an instrument in writing signed by the party against which enforcement of the change or waiver is sought. 15. Section Headings. The section headings in this Warrant are for the convenience of the parties and in no way alter, modify, amend, limit or restrict the contractual obligations of the parties. 16. Governing Law. This Warrant will be governed by and construed in accordance with the internal laws of the State of Minnesota (without reference to the conflicts of law provisions thereof). EXECUTED as of the Date of Issuance indicated above. APA OPTICS, INC. By:________________________________ Title:_______________________________ ATTEST: _________________________ 8 EXHIBIT I PURCHASE FORM To:_________________ Dated:____________ The undersigned, pursuant to the provisions set forth in the attached Warrant (No. ___), hereby irrevocably elects to purchase (CHECK APPLICABLE BOX): [ ] _____ shares of the Common Stock covered by such Warrant; or [ ] the maximum number of shares of Common Stock covered by such Warrant pursuant to the cashless exercise procedure set forth in Section 1(b). The undersigned herewith makes payment of the full purchase price for such shares at the price per share provided for in such Warrant, which is $________. Such payment takes the form of (CHECK APPLICABLE BOX OR BOXES): [ ] $______ in lawful money of the United States; and/or [ ] the cancellation of such portion of the attached Warrant as is exercisable for a total of _____ Warrant Shares (using a Fair Market Value of $_____ per share for purposes of this calculation); and/or [ ] the cancellation of such number of Warrant Shares as is necessary, in accordance with the formula set forth in Section 1(b), to exercise this Warrant with respect to the maximum number of Warrant Shares purchasable pursuant to the cashless exercise procedure set forth in Section 1(b). Signature: ______________________ Address: ______________________ ______________________ EXHIBIT II ASSIGNMENT FORM FOR VALUE RECEIVED, ________________________________________ hereby sells, assigns and transfers all of the rights of the undersigned under the attached Warrant (No. ____) with respect to the number of shares of Common Stock covered thereby set forth below, unto: Name of Assignee Address No. of Shares - ---------------- ------- ------------- Dated:_____________________ Signature:________________________________ Signature Guaranteed: By: ________________________________ The signature should be guaranteed by an eligible guarantor institution (banks, stockbrokers, savings and loan associations and credit unions with membership in an approved signature guarantee medallion program) pursuant to Rule 17Ad-15 under the Securities Exchange Act of 1934.