Fabrication tolerant polarization splitter and rotator based on a tapered directional coupler

Abstract

A polarization splitter and rotator (PSR) based on a tapered directional coupler with relaxed fabrication tolerance is proposed and demonstrated on the silicon-on-insulator platform. The device is simply constructed by parallel-coupling a narrow silicon waveguide with a linearly tapered wider waveguide. Compared to previously reported PSRs based on a normal directional coupler, which suffer from stringent requirements on the accuracy of the narrow waveguide width, the introduced tapered structure of the wide waveguide can be used to compensate the fabrication errors of the narrow waveguide. In addition, only a single step of exposure and etching is needed for the fabrication of the device. Similar high conversion efficiencies are experimentally demonstrated for a narrow waveguide width deviation of 14 nm with large tolerance to the coupler length.

Mode-selective wavelength conversion based on four-wave mixing in a multimode silicon waveguide

“…5(a), was fabricated on a SOI wafer (top silicon layer: 250 nm, buried silicon dioxide layer: 1 μm). Tapered DCs are used as TE 0 &TE 1 mode (de)multiplexers thanks to their simple structure and larger fabrication tolerance than normal DCs [7,20]. Fully etched apodized grating couplers [21] are used as input and output ports.…”

Mode-selective wavelength conversion based on four-wave mixing in a multimode silicon waveguide

“…2(a), was fabricated on a SOI wafer (top silicon layer: 250 nm, buried silicon dioxide layer: 1 μm). Tapered DCs are used as TE 0 &TE 1 mode (de)multiplexers thanks to their simple structure and larger fabrication tolerance than normal DCs 4,8 . A single step of E-beam lithography and inductively coupled plasma reactive ion etching was used for the fabrication.…”

Polarization Diversity DPSK Demodulator on the Silicon-on-Insulator Platform with Simple Fabrication

“…However, this scheme is limited by the insertion loss and bandwidth of the grating coupler. Another method is based on polarization splitter and rotator (PSR) technology [13][14][15][16][17][18]. Recently a Pol-D circuit for NRZ-DPSK demodulation relying on an asymmetrical coupler-based PSR has been demonstrated [19].…”