Exhibit 99.4

UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL INFORMATION

On September 24, 2019 (the “Closing Date”), II-VI Incorporated (“II-VI”) completed its acquisition of Finisar Corporation (“Finisar”), a global technology leader for subsystems and components for fiber optic communications (“the Acquisition”).

The unaudited pro forma condensed combined financial information was prepared in accordance with Article 11 of Regulation S-X. The unaudited pro forma adjustments reflecting the Acquisition and other transactions described in this section and under “Notes to Unaudited Pro Forma Condensed Combined Financial Information” have been prepared in accordance with the acquisition method of accounting in accordance with FASB ASC Topic 805, Business Combinations, where II-VI is the accounting acquirer and Finisar is the accounting acquiree.

The unaudited pro forma combined balance sheet has been prepared to reflect the transaction as if the transaction had occurred on June 30, 2019. The unaudited pro forma combined statement of operations for the year-ended June 30, 2019 combine the results of operations of II-VI and Finisar for the fiscal years ended June 30, 2019 and April 28, 2019, respectively, as if the transaction had occurred on July 1, 2018.

The unaudited pro forma condensed combined financial statements have been adjusted to give effect to pro forma events that are (i) directly attributable to the Acquisition, (ii) factually supportable, and (iii) expected to have a continuing impact on the combined company’s results.

The unaudited pro forma condensed combined financial information is provided for illustrative purposes only and does not purport to represent what the actual consolidated results of operations or consolidated financial condition would have been had the Acquisition actually occurred on the dates indicated, nor do they purport to project the future consolidated results of operations or consolidated financial condition for any future period or as of any future date. The assumed accounting for the Acquisition, including the aggregate Acquisition Consideration, is based on provisional amounts, and the associated purchase accounting is not final. The preliminary allocation of the purchase price to the acquired assets and assumed liabilities was based upon the preliminary estimate of fair values. For the preliminary estimate of fair values of assets acquired and liabilities assumed of Finisar, II-VI used publicly available benchmarking information as well as a variety of other assumptions, including market participant assumptions. The unaudited pro forma adjustments are based upon available information and certain assumptions that II-VI believes are reasonable under the circumstances. Actual results may differ materially from the assumptions within the accompanying unaudited pro forma condensed combined financial information. The purchase price adjustments relating to the Finisar and II-VI combined financial information are preliminary and subject to change, as additional information becomes available and as additional analyses are performed. All pro forma adjustments and their underlying assumptions are described more fully in the notes to the unaudited pro forma condensed combined financial information.

Notes to Unaudited Pro Forma Condensed Combined Financial Information

Note 1. Description of the Acquisition

II-VI Incorporated (“II-VI” or “the Company”) and Finisar Corporation (“Finisar”) entered into an Agreement and Plan of Acquisition, dated as of November 8, 2018 (the “Acquisition Agreement”). Pursuant to the terms of the Acquisition Agreement, Mutation Merger Sub Inc., a wholly owned subsidiary of II-VI, merged with and into Finisar, with Finisar surviving the Acquisition and becoming a wholly owned subsidiary of II-VI. On September 24, 2019 (the “Closing Date”), the Company completed its acquisition of Finisar (the “Acquisition”). Each issued and outstanding share of Finisar’s common stock was automatically cancelled and converted into the right to receive the following consideration (collectively the “Acquisition Consideration”), at the election of the holder of the share of Finisar’s common stock:

The per share Cash Consideration and Stock Consideration were subject to adjustment pursuant to the terms of the Acquisition Agreement such that the aggregate Acquisition Consideration consisted of approximately 60.0% cash and approximately 40.0% shares of the Company’s common stock (assuming a per share price of the Company’s common stock equal to the closing price as of November 8, 2018, which was $46.88 per share) across all shares of Finisar’s common stock (the “Proration Adjustment”). Following the Proration Adjustment, the resulting consideration for Cash Consideration was adjusted to $15.94 in cash and 0.2146 shares of the Company’s common stock (“II-VI Common Stock”). No adjustment was made to the Stock Consideration and Mixed Consideration.

Note 2. Description of Financing Transactions

New Senior Credit Facilities

On September 24, 2019, in connection with the Acquisition, the Company entered into an Amended and Restated Credit Agreement (the “New Credit Agreement”) with Bank of America, N.A., as Administrative Agent, Swing Line Lender and a Line of Credit Issuer, and the other lenders party thereto.

The New Credit Agreement provides for senior secured financing of $2.425 billion in the aggregate, consisting of:

The New Credit Agreement also provides for a letter of credit sub-facility not to exceed $25.0 million and a swing loan sub-facility initially not to exceed $20.0 million.

The Company is obligated to repay the outstanding principal amount of the Term A Facility in quarterly installments equal to 1.25% of the initial aggregate principal amount of the Term A Facility, with the remaining outstanding balance due and payable on the fifth anniversary of the Closing Date. Similarly, the Company is obligated to repay the outstanding principal amount of the Term B Facility in quarterly installments equal to 0.25% of the initial aggregate principal amount of the Term B Facility, with the remaining outstanding balance due and payable on the seventh anniversary of the Closing Date. The Company is obligated to repay the aggregate principal amount of all outstanding revolving loans made under the Revolving Credit Facility on the fifth anniversary of the Closing Date.

The Company’s obligations under the New Senior Credit Facilities are guaranteed by each of the Company’s existing or future direct and indirect domestic subsidiaries, including Finisar and its domestic subsidiaries (collectively, the “Guarantors”). Borrowings under the New Senior Credit Facilities are collateralized by a first priority lien in substantially all of the assets of the Company and the Guarantors, except that no real property is collateral under the New Senior Credit Facilities.

All amounts outstanding under the New Senior Credit Facilities will become due and payable 120 days prior to the maturity of the Company’s currently outstanding 0.25% Convertible Senior Notes due 2022 (the “II-VI Notes”) if (i) the II-VI Notes remain outstanding, and (ii) the Company has insufficient cash and borrowing availability to repay the principal amount of the II-VI Notes.

The Company voluntarily may prepay, at any time or from time to time, any amounts outstanding under the New Senior Credit Facilities in whole or in part without premium or penalty; except for the Term B Facility, in which (a) a repayment made before September 24, 2020, (b) the occurrence of a repricing event, or (c) a change to the lenders, the Company will be subject to a prepayment premium in a an amount equal to one percent of: (i) the principal amount of the Term B Facility that is prepaid under an optional or mandatory prepayment due to a repricing event, (ii) the aggregate outstanding principal amount of the Term B Facility resulting from an amendment to the New Credit Agreement, and (iii) the principal amount of the Term B Facility that is mandatorily assigned. The Company may be subject to mandatory prepayment of amounts outstanding under the New Senior Credit Facilities under certain circumstances, including in connection with certain asset sales or other dispositions of property and debt issuances.

The Company also may be required to prepay amounts under the Term B Facility based on the Company’s excess cash flow (as calculated in accordance with the terms of the New Credit Agreement) for the Company’s prior fiscal year beginning with its fiscal year ending June 30, 2020 and the Company’s consolidated secured net leverage ratio (as calculated in accordance with the terms of the New Credit Agreement) as of the end of such fiscal year.

Amounts outstanding under the New Senior Credit Facilities will bear interest at a rate per annum equal to an applicable margin over a eurocurrency rate or an applicable margin over a base rate determined by reference to the highest of (a) the federal funds rate plus 0.50%, (b) Bank of America, N.A.’s prime rate and (c) a eurocurrency rate plus 1.00%, in each case as calculated in accordance with the terms of the New Credit Agreement. The applicable interest rate would increase under certain circumstances relating to events of default.

The New Credit Agreement contains customary affirmative and negative covenants with respect to the New Senior Credit Facilities, including limitations with respect to liens, investments, indebtedness, dividends, acquisitions, dispositions of assets and transactions with affiliates. The Company will be obligated to maintain a consolidated interest coverage ratio (as calculated in accordance with the terms of the new Credit Agreement) as of the end of each fiscal quarter of not less than 3.00 to 1.00. The Company will be obligated to maintain a consolidated total net leverage ratio (as calculated in accordance with the terms of the New Credit Agreement) of not greater than (i) 5.00 to 1.00 for the first four fiscal quarters after the Closing Date, commencing with the first full fiscal quarter after the Closing Date, (ii) 4.50 to 1.00 for the fifth fiscal quarter through and including the eighth fiscal quarter after the Closing Date, and (iii) 4.00 to 1.00 for each subsequent fiscal quarter.

0.50% Finisar Convertible Notes

Finisar’s outstanding 0.50% Convertible Senior Notes due 2036 (the “Finisar Notes”) may be redeemed at any time on or after December 22, 2021 in whole or in part at the option of the Company at a redemption price equal to one hundred percent (100%) of the principal amount of such Finisar Notes plus accrued and unpaid interest. Each holder of Finisar Notes also may require Finisar to repurchase all or any portion of such holder’s outstanding Finisar Notes for cash on December 15, 2021, December 15, 2026 and December 15, 2031 at a repurchase price equal to one hundred percent (100%) of the principal amount of such Finisar Notes plus accrued and unpaid interest. The Finisar Notes will mature on December 15, 2036. Interest on the Finisar Notes accrues at 0.50% per annum, paid semi-annually, in arrears, on June 15 and December 15 of each year.

In connection with the acquisition of Finisar, the Company, Finisar and Wells Fargo Bank, National Association, as trustee, entered into a First Supplemental Indenture, dated as of September 24, 2019 (the “First Supplemental Indenture”). The First Supplemental Indenture supplements the base indenture (as supplemented, the “Finisar Indenture”), which governs the Finisar Notes. Pursuant to the terms of the First Supplemental Indenture, the Company has fully and unconditionally guaranteed, on a senior unsecured basis, the due and punctual payment and performance of all obligations of Finisar to the holders of the Finisar Notes. The First Supplemental Indenture also provides that the right of holders of Finisar Notes to convert Finisar Notes into cash and/or shares of Finisar’s common stock is changed to a right to convert Finisar Notes into cash and/or shares of II-VI Common Stock, subject to the terms of the Finisar Indenture.

Under the terms of the Finisar Indenture, the consummation and effectiveness of the Acquisition on the Closing Date constituted a Fundamental Change (as defined in the Finisar Indenture) and a Make-Whole Fundamental Change (as defined in the Finisar Indenture). Accordingly, in accordance with the terms of the Finisar Indenture, each holder of Finisar Notes had the right to (i) convert its Finisar Notes into cash and/or shares of Company Common Stock, at Finisar’s option, or (ii) require that Finisar repurchase such holder’s Finisar Notes for an amount in cash equal to one hundred percent (100%) of the principal amount of such Finisar Notes plus accrued and unpaid interest.

Note 3. Basis of Pro Forma Presentation

The unaudited pro forma condensed combined financial information was prepared pursuant to Article 11 of Regulation S-X.

II-VI’s fiscal year ends on June 30. Prior to the consummation of the Acquisition, Finisar had a 52- or 53-week fiscal year ending on the Sunday closest to the last day of April in each calendar year. Finisar’s most recent fiscal year ended on April 28, 2019. Financial information for Finisar for the year-ended April 28, 2019 has been used in preparation of the unaudited pro forma condensed combined financial information.

The unaudited pro forma combined balance sheet has been prepared to reflect the transaction as if the transaction had occurred on June 30, 2019. The unaudited pro forma combined statement of operations combine the results of operations of II-VI and Finisar for their respective fiscal years ended June 30, 2019 and April 28, 2019 as if the transaction had occurred on July 1, 2018, the beginning of the Company’s 2019 fiscal year.

The unaudited pro forma condensed combined financial information has been prepared using the acquisition method of accounting in accordance with the business combination accounting guidance as provided in FASB ASC Topic 805, Business Combinations (“ASC 805”), with II-VI treated as the accounting acquirer and Finisar as the accounting acquiree. The unaudited pro forma condensed combined financial information may differ from the final purchase accounting for a number of reasons, including the fact that the estimates of fair values of assets and liabilities acquired are preliminary and subject to change when the formal valuation and other studies are finalized. The differences that may occur between the preliminary estimates and the final purchase accounting could have a material impact on the accompanying unaudited pro forma condensed combined financial information.

The historical consolidated financial information of II-VI and Finisar has been adjusted in the unaudited pro forma condensed combined financial information to give effect to pro forma matters that are (i) directly attributable to the Acquisition, and the financing used to finance the Acquisition, (ii) factually supportable and (iii) with respect to the unaudited pro forma condensed combined statement of operations, expected to have a continuing impact on the operating results of the combined company. The unaudited pro forma condensed combined financial information does not give effect to the potential impact of any anticipated synergies, operating efficiencies or cost savings that may result from the Acquisition or of any future integration costs.

The unaudited pro forma condensed combined financial information is provided for illustrative purposes only and does not purport to represent what the actual consolidated results of operations or the consolidated financial position of the Company would have been had the Acquisition occurred on the dates assumed, nor is it necessarily indicative of the future consolidated results of operations or consolidated financial position of the combined company. The unaudited pro forma condensed combined financial information was based on, and should be read in conjunction with, the following historical consolidated financial statements and accompanying notes:

Note 4. Summary of Significant Accounting Policies

The accounting policies used in the preparation of the unaudited pro forma condensed combined financial information are those set out in the Company’s audited consolidated financial statements as of and for the year ended June 30, 2019. Management has determined that certain adjustments, including those described in Notes 8 and 9, are necessary to conform Finisar’s financial statements to the accounting policies used by the Company in the preparation of the unaudited pro forma condensed combined financial information. The adjustment amounts are subject to change as further assessment is performed and finalized for purchase accounting. These reclassifications and adjustments have no effect on previous reported total assets, total liabilities, shareholders’ equity or income from continuing operations of the Company or Finisar.

Note 6. Preliminary Estimate of Assets to be Acquired and Liabilities to be Assumed

The Company allocated the fair value of the purchase price consideration to the tangible assets, liabilities, and intangible assets acquired, generally based on estimated fair values. The excess purchase price over those fair values is recorded as goodwill. Our valuation assumptions of acquired assets and assumed liabilities require significant estimates, especially with respect to intangible assets. Our preliminary allocation of the purchase price of Finisar, based on the estimated fair value of the assets acquired and liabilities assumed as of the Closing Date, is as follows (in millions):

The purchase price allocation set forth herein is preliminary and will be revised as additional information becomes available during the measurement period, which could be up to 12 months from the Closing Date. Any such revisions or changes may be material. The Company utilized market available benchmarking analysis to perform the preliminary allocation above.

The amortization related to the identifiable intangible assets is reflected as a pro forma adjustment in the unaudited pro forma condensed combined statement of operations based on the estimated useful lives above and as further described in Note 9(b). The identifiable assets and related amortization are preliminary and are based on management’s estimates after consideration of similar transactions. As discussed above, the amount will ultimately be allocated to identifiable intangible assets, and the related amount of amortization may differ materially from this preliminary allocation. In addition, the periods over which the amortization impacts will ultimately be based upon the periods in which the associated economic benefits are expected to be derived, or where appropriate, based on the use of straight-line method or other acceptable methods. Therefore, the amount of amortization following the Acquisition may differ significantly between periods based upon the final value assigned and amortization methodology used for each identifiable intangible asset.

Note 7. Reclassification Adjustments

The following reclassification adjustments were made to conform the presentation of Finisar’s financial information to II-VI’s presentation:

Note 8. Pro Forma Adjustments for Condensed Combined Balance Sheet

Note 9. Pro Forma Adjustments for Condensed Combined Statement of Operations