Yoshiaki KOMMA,1 Shin-ichi KADOWAKI,1 Seiji NISHINO,1 Yoshikazu HORI2 and Makoto KATO1

1Optical Disk Systems Development Center, Matsushita Electric Industrial Co., Ltd., 1006, Kadoma, Kadoma-shi, Osaka, 571 Japan, 2Semiconductor Research Center, Matsushita Electric Industrial Co., Ltd., 3-1-1, Yagumonakamachi, Moriguchi-shi, Osaka, 570 Japan

(Received October 2, 1995; Accepted May 15, 1996)

Diffraction efficiencies of a reflection-type blazed holographic optical element (HOE) are analyzed and optimized for use in a totally integrated optical head. The HOE, consisting of four-step phase levels, was fabricated by a double-etching process. By controlling each etching depth, signal light power efficiency was maximized to 16% and the power ratio of noise components relative to signal light power was suppressed to 21%. Diffraction efficiencies were made uniform over the entire HOE in oblique positioning by controlling the respective step widths of the HOE.

Key words : holographic optical element, blazed HOE, diffraction efficiency, integrated optical head