1 × 4 Wavelength Demultiplexer C-Band Using Cascaded Multimode Interference on SiN Buried Waveguide Structure

Abstract

Back reflection losses are a key problem that limits the performances of optical communication systems that work on wavelength division multiplexing (WDM) technology based on silicon (Si) Multimode Interference (MMI) waveguides. In order to overcome this problem, we propose a novel design for a 1 × 4 optical demultiplexer based on the MMI in silicon nitride (SiN) buried waveguide structure that operates at the C-band spectrum. The simulation results show that the proposed device can transmit four channels with a 10 nm spacing between them that work in the C-band with a low power loss range of 1.98–2.35 dB, large bandwidth of 7.68–8.08 nm, and good crosstalk of 20.9–23.6 dB. Thanks to the low refractive index of SiN, a very low back reflection of 40.57 dB is obtained without using a special angled MMI design, which is usually required, using Si MMI technology. Thus, this SiN demultiplexer MMI technology can be used in WDM technique for obtaining a high data bitrate alongside a low back reflection in optical communication systems.

Miniaturization of 2 × 4 90-Degree Hybrid Optical Couplers

“…The expression (10) holds for both the modes in the input and output waveguides and it gives a linear dependence between the number of modes and the width of the device, which means that the width of the working devices can be associated to the number of modes.…”

“…The working principle is based on self-imaging caused by internal interference of the modes excited and propagating in it [2], [4]- [6]. They find an impressive number of applications such as splitter [7], couplers [8], multiplexers [9], demultiplexers [10], power combiners [11], filters [12], sensors [13], active components [14] to name a few. 90-degree hybrid couplers are a subclass of MMIs, which finds applications in coherent detection systems.…”

Silica-Titania Integrated Photonics Platform-Based 1 × 2 Demultiplexer Utilizing Two Serially Cascaded Racetrack Microrings for 1310 nm and 1550 nm Telecommunication Wavelengths

“…To distinguish these channels from one another and send them to their appropriate users, a proper photonic device is required at the user end of the network. Mach-Zehnder interferometers (MZI) [5,6], multimode interference (MMI) couplers [7][8][9], Y-branch devices [10,11], ring resonators [12][13][14][15], and other solutions can all be used to create optical demultiplexers based on different optical platforms, which are a crucial components of communication networks [16][17][18][19]. Moreover, small size and low crosstalk demultiplexer devices may have advantages in quantum information processing and quantum communication [20][21][22].…”

“…NIL is an etch-less fabrication method. It requires the previous fabrication of a "master stamp" and imprinting it over the deposited non-hardened WG film before the thermal annealing to form the structures [7]. However, both wet chemical etching and NIL are still under development for the SiO 2 :TiO 2 platform and give a less probable successful fabrication effect than ICP-RIE.…”

A silicon nitride MMI O-band power combiner based on slot waveguide structures

“…Researchers also show the ability to use slot waveguide technology for realization of TM/TE polarization [31] and green demultiplexer [32]. The using of SI3N4 waveguides for realization of optical devices such as combiner [33][34] and demultiplexer [35][36] have been reported recently. In this work, we propose a design of a 4×1 MMI power combiner based on SI3N4 slot waveguide technology.…”