纳米孔径激光器出射孔径设计

Aperture Design of Nano-Aperture Semiconductor Laser

采用三维时域有限差分(FDTD)方法计算和比较了不同形状和尺寸的纳米孔径半导体激光器的近场分布特性,结果表明采用C形孔径设计可使纳米孔径激光器的输出光强最大值比方孔和圆孔提高了3～4个数量级,通光效率也会有显著提高而聚焦光斑尺寸基本不变。并提出C形孔在孔径尺寸为1/3波长左右时输出光场分布最优。纳米孔径激光器可用于超高密度近场光存储、近场光学超衍射分辨成像、纳米光刻等。

The near-field distributions of nano-aperture semiconductor lasers with different shapes and dimensions were characterized by the method of 3-D finite-difference time-domain (FDTD). The calculation result reveals that the light intensity peak of the C-aperture is increased about 1000 times or more than that of the normal square or circular aperture with a comparable spot size and there is on obvious increase in power throughput. The maximum of the field enhancement occurs at the aperture size corresponding to one third of wavelength. This kind of nano-aperture semiconductor lasers can be used for the high density optical data storage, near field super resolution imaging and nano-photolithography.