Application of 64 channel laser for free space interconnections

Abstract

We analyze and simulate the optical properties of the frequency hopping wavelength division multiplexing (WDM) laser. In order to design the multi-channel wavelength hopping laser as the light source of optics to the x(OTTx), our investigation describes how to design, simulate of 64×64 Array Waveguide Grating (AWG) on the silicon-on-insulator (SOI) substrate. The achieved AWG has a channel spacing of 0.4 nm (50GHz) with its spectrum centered at 1550.52 nm. The number of arrayed waveguides is 266 and the length difference is 9.89μm. We find out an optimal value of waveguide separation at the junction between arrayed waveguides region and free propagation region. In order to get a better uniformity for 64 channel outputs while insertion loss and crosstalk are taken into account, we also describe the improved design by using tapered waveguide structure at the both ends of AWG. The experimental results show the flatness can be improved to 0.71 dB which is very close to our previous simulation works. We also analyze the concentration effect of doping Er, cross-talk and thermal effect in SOI waveguide. We investigate the optical sphericity mirror station (BS) and relay station (RS) in OTTx system. We use the uniformity for 64 channel outputs as the light source of wavelength hopping laser of this system. The optic signals convert to the receiving signal by 4G over OTTx signal converting technique in this system.