Efficient 1.55 and 2 m Dual-Band SOI Grating Coupler for Light Coupling and On-Chip Wavelength Division (De)multiplexing

Efficient fiber-chip couplers operating at distinct wavelength bands are key components to combine or split different optical bands for emerging data transmission and nonlinear applications. Herein, a dual-band silicon-integrated grating coupler (GC) operated at 1.55 and 2 mu m wavebands is designed and demonstrated. The proposed device can simultaneously couple 1.55 and 2 mu m wavebands light into the in-plane waveguides at the same incident angle. Numerical simulations indicate that coupling efficiencies (CEs) are -2.5 and -3.9 dB for center wavelengths at 1561 and 1979 nm, respectively. The dual-band GC is experimentally demonstrated on a commercially available 340 nm silicon-on-insulator wafer. The fabricated dual-band GC with center wavelengths of 1559 and 1968 nm obtains CEs of -4.9 and -6.4 dB, with 3 dB bandwidths of 81 and 80.4 nm, respectively. Also, the first proof-of-concept demonstration of 10 Gb s(-1) wavelength division multiplexing transmission at 1.55 and 2 mu m waveband is presented based on the fabricated dual-band GC.