[20a-S621-1~8] 3.15 Silicon photonics

△ [20a-S621-7] High coupling efficiency Si-wire grating couplers by ArF-immersion lithography

〇Yohei Sobu¹, Seok-hwan Jeong¹, Yu Tanaka¹, Ken Morito¹ (1.PETRA)

Keywords:Grating coupler,Silicon photonics

We report two kinds of Si-wire grating couplers for transmitter (SP: single polarization GC) and receiver (PS: polarization splitting GC) as optical couplers of integrated optical IO device. In the transmitter, we used the apodized grating to match the radiation mode from SPGC with Gaussian-shaped profile. As a result, the coupling loss between SPGC and a 10°-oriented single mode fiber (SMF) was measured to be -2.2 dB at a wavelength of 1550 nm. In the receiver, the PSGC which is composed of circular-type air holes and two output waveguides oriented 90° of one another operates with an arbitrary polarization. From the viewpoint of the adjustment of the phase matching and the wave front, the waveguides of PSGC were tilted and the scattering elements of PSGC were changed to be like rhomboid. As a result, the coupling loss of PSGC was measured to be -4.5 dB and -14dB optical crosstalk was obtained.