Siddharth Nambiar

Silicon photonic IC embedded optical-PCB for high-speed interconnect application

Optical-Printed Circuit Board (PCB) is an emerging optical interconnect technology to bridge the gap between the board edge and the processing module. The technology so far has been used as a broadband transmitter using polymer waveguides in the PCB. In this paper, we report a Silicon Nitride based photonic IC embedded in the PCB along with the polymers as waveguides in the PCB. The motivation for such integration is to bring routing capability and to reduce the power loss due to broadcasting mode.

Integrated silicon nitride based TE dual-band grating coupler

Grating based fiber-chip couplers are an excellent scheme to couple between a sub-micron waveguide and an optical fiber. However, the operation bandwidth of the grating couplers is restricted to a particular wavelength band though high-coupler efficiency is achievable. An application such as Passive Optical Networks that use both O and C-band, it becomes essential to that grating couplers can be operated in two wavelength bands. We found very limited work on dual/multi-band grating coupling, which is an important part of a PON transceiver. However, dual-band grating with polarization splitting has been previously reported [2] in SOI platform. In this work, we propose and demonstrate a dual-band grating operating in O and C-band. The proposed dual-band grating coupler is implemented in Silicon Nitride (SiN) waveguide platform that is starting to emerge as an attractive alternative photonics circuit platform [3]. Unlike earlier demonstrations, both bands are directed to a single waveguide. To the best of our knowledge, this is the first ever demonstration of a unidirectional single polarization dual band grating couple.

Subwavelength grating fiber chip coupler in SOI with enhanced bandwidth and efficiency

We numerically investigate sub-wavelength based grating coupler in SOI platform. By optimized design we achieve a maximum coupling efficiency of 2.5 dB and 0.85 dB with Si substrate and Bragg mirrors respectively.