Abstract
A thermally tunable 1 × 4 channel optical demultiplexer was designed using an ultra low-loss Si3N4 (propagation loss ~3.1 dB/m) waveguide. The demultiplexer has three 2 × 2 Mach-Zehnder interferometers (MZI), where each of the MZI contains two 2 × 2 general interference based multimode interference (MMI) couplers. The MMI couplers exhibit −3.3 dB to −3.7 dB power division ratios over a 50 nm wavelength range from 1530 nm to 1580 nm. The chrome-based (Cr) heaters placed on the delay arms of the MZI filters enable thermal tuning to control the optical phase shift in the MZI delay arms. This facilitates achieving moderately low crosstalk (14.5 dB) between the adjacent channels. The optical insertion loss of the demultiplexer per channel is between 1.5 dB to 2.2 dB over the 1550 nm to 1565 nm wavelength range. Error free performance (BER of 10−12) is obtained for all four 40 Gb/s data rate channels. The optical demultiplexer is an important tool towards building photonic integrated circuits with complex optical signal processing functionalities in the low-loss Si3N4 waveguide platform.
Highlights
The growth of internet traffic over the last decade has pushed data capacity and increased the processing speed demand in modern computational server based networks such as data centers
For the applications where large optical time delays are required in addition to the wavelength filtering, the arrayed-waveguide grating (AWG) based multiplexer and Mach-Zehnder interferometers (MZI) filter based demultiplexer can be used together to build the complete photonic integrated circuits (PIC) on chip [1]
The performance results of the 1 × 4 channel optical demultiplexer circuit reported in this article suggests that complex optical signal processing functionalities can be added to the Si3N4 waveguide based components such that more advantage from this ultra low-loss PIC technology can be harnessed
Summary
The growth of internet traffic over the last decade has pushed data capacity and increased the processing speed demand in modern computational server based networks such as data centers. To design an integrated version of the PWM circuit, low-loss Si3N4 waveguides can be used to build its key building blocks (i.e., a demultiplexer to filter the optical channels and the long delay lines to implement the time delay between the adjacent channels). For the applications where large optical time delays are required in addition to the wavelength filtering, the AWG based multiplexer and MZI filter based demultiplexer can be used together to build the complete PIC on chip [1]. We present the analysis and experimental results of a 1 × 4 channel MZI based wavelength demultiplexer designed using the 2.8 μm × 72 nm cross-section area Si3N4 waveguide. We will present the simulation method and results used to design the MMI couplers and the overall MZI based demultiplexer
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
