Athermal 4-channel (de-)multiplexer in silicon nitride fabricated at low temperature
We have designed and realized an athermal 4-channel wavelength (de-)multiplexer in silicon nitride (SiN). Minimized thermal sensitivity is achieved in a wide wavelength range by using wide and narrow waveguides with low and different thermal-optic coefficients in the two arms of Mach–Zehnder interferometers (MZIs). The SiN core layer and SiO2 cladding layers are deposited by a low-temperature plasma-enhanced chemical vapor deposition process. The fabricated MZI filter exhibits a thermal sensitivity within ±2.0 pm/°C in a wavelength range of 55 nm to near 1300 nm. Then, an athermal (de-)multiplexer based on cascaded MZIs has been demonstrated with a crosstalk ≤?22 dB and a thermal sensitivity <4.8 pm/°C for all four channels, reduced by 77% compared to a conventional SiN (de-)multiplexer. Owing to the passive operation and compatibility with the CMOS backend process, our devices have potential applications in 3D integration of photonics and electronics.
基金项目：863 Program (2015AA016904); National Natural Science Foundation of China (NSFC)10.13039/501100001809 (61335002, 11574102, 61675084, 61775094).
Qingzhong Huang：Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Chinae-mail: firstname.lastname@example.org
Liangqiu Zhu：Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
Jun Liu：Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
Yinglu Zhang：Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
Ying Huang：Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
Yi Wang：Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
Jinsong Xia：Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, Chinae-mail: email@example.com
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Shiqi Tao, Qingzhong Huang, Liangqiu Zhu, Jun Liu, Yinglu Zhang, Ying Huang, Yi Wang, and Jinsong Xia, "Athermal 4-channel (de-)multiplexer in silicon nitride fabricated at low temperature," Photonics Research 6(7), 686-691 (2018)