Research On Silicon Based Shallow Etching Micro/nano Grating Beam Splitters

Grating is an enduring source of optical device, it is still during the process of developing and improving with the developments of modern micro-nino production technology and integrated photonics circuit especially the development of silicon-based photonics. As with other photoelectric devices, grating makes great contribution to the developments of economy and society, To silica-based integrated circuit, grating possesses many advantages such as convenient to the phase matching, beam coupling and shaping, and wavelength conversion; moreover, it has the simple structure and craftsmanship, and easy to integration, has been widely used in the integration of the light path of active and passive components. In view of the silica micro-nano optical device is used to realize the light path integration, chip photoelectric conversion and detecting, all research contents of this paper will focus on the micro-nano scale.In this paper, two kinds of beam splitter of structure silicon-based micro-nano grating have been researched based on rigorous coupled-wave analysis and the finite-different time-domain, and take example by silicon-on-insulator (SOI) material system that used into the microelectronics processing technology:(1) By using the asymmetric gratings to control spectrum component of the grating regional distribution and stop the leak mode in grating fast attenuation, so as to realize the broadband, large Angle, and high diffraction efficiency unique properties, This paper has designed and optimized a double function of the single polarization grating splitter that, when TE polarization wave (nearby1550nm band) perpendicular incident, the reflectivity of this device can reach the97%; when TM polarization wave perpendicular incident, its can produce about50:50light reflection and transmission. In addition, we use the finite difference time domain algorithm rigorous coupled wave analysis method validation of the grating the correctness of design.(2) In addition, based on multi-level uniform cycle of grating structure, this paper has also designed and optimized a kind of1x3sub-wavelength grating power splitter which possesses high performance and polarization irrelevant,. Nearby the1550nm band, when the incident light illuminate vertically, the device to TE of polarized light grade0and grade±1transmission rate of31%,32%and32%respectively; For TM polarized light grade0and grade1transmission rate of33%,32%and32%respectively.