[OPTICAL REVIEW Vol. 17, No. 4 (2010) 404-409]
© 2010 The Japan Society of Applied Physics

Subwavelength-Sized Beam Spot Confinement Using an Optical Thin Core Dielectric Ridge-Type Waveguide in Leaky Mode

Shin-ya HASEGAWA and Fumihiro TAWA1

Human Centric Computing Laboratories, Fujitsu Laboratories Ltd., 10-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0124, Japan
1Enterprise Server Business Unit, Fujitsu Ltd., 4-1-1 Kamikodanaka, Nakahara, Kawasaki 211-8588, Japan

(Received December 23, 2009; Revised April 12, 2010; Accepted May 6, 2010)

Optical near-field plasmon-enhancement techniques have made marked contributions to the field of subwavelength optical beam spot generation for photonic devices. However, the metal material used is not sufficiently heat resistant for high-temperature operating requirements, such as laser-assisted magnetic recording storage. Therefore, it is preferable to use a dielectric material as a heat source for this application. To realize a subwavelength optical beam spot size using a dielectric material, we extensively analyze a leaky mode dielectric waveguide with a thin core. Finally, we show a new ridge-type dielectric waveguide using a leaky mode operation for a subwavelength beam spot.

Key words: optical waveguide, leaky mode, ridge-type waveguide, FDTD method, laser-assisted magnetic recording, resonance mode, radiation mode