Spatially resolved multimode excitation for smooth supercontinuum generation in a SiN waveguide

• Published in: Optics express Vol. 31; no. 4; p. 6088
• Main Authors: Kou, Rai, Ishizawa, Atsushi, Yoshida, Koki, Yamamoto, Noritsugu, Xu, Xuejun, Kikkawa, Yugo, Kawashima, Kota, Aihara, Takuma, Tsuchizawa, Tai, Cong, Guangwei, Hitachi, Kenichi, Nishikawa, Tadashi, Oguri, Katsuya, Yamada, Koji
• Format: Journal Article
• Language: English
• Published: United States 13.02.2023
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.478481

We propose a method of supercontinuum light generation enhanced by multimode excitation in a precisely dispersion-engineered deuterated SiN (SiN:D) waveguide. Although a regularly designed SiN-based nonlinear optical waveguide exhibits anomalous dispersion with the fundamental and first-order multimode operation, the center-symmetric light pumping at the input edge has so far inhibited the full potential of the nonlinearity of SiN-based materials. On the basis of numerical analysis and simulation for the SiN:D waveguide, we intentionally applied spatial position offsets to excite the fundamental and higher-order modes to realize bandwidth broadening with flatness. Using this method, we achieved an SNR improvement of up to 18 dB at a wavelength of 0.6 µm with an offset of about 1 µm in the Y-axis direction and found that the contribution was related to the presence of dispersive waves due to the excitation of TE 10 , and TE 01 modes.