EX-23 4 ex2301.txt INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Statement No. 333-74682 of II-VI Incorporated on Form S-8 of our report dated September 25, 2003, appearing in this Annual Report on Form 10-K of II-VI Incorporated and subsidiaries for the year ended June 30, 2003. /s/ Deloitte & Touche LLP Pittsburgh, Pennsylvania September 25, 2003