Second-Order Microring Filter with Large Free-Spectral-Range and Wavelength-Tunable-Range over 50 nm
Jiamei Gu,
Shuojian Zhang,
Qiongchan Shao,
Mingyu Li,
Xiao Ma,
Jian-Jun He
Affiliations
Jiamei Gu
State Key Laboratory of Extreme Photonics and Instrumentation, Centre for Integrated Optoelectronics, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
Shuojian Zhang
State Key Laboratory of Extreme Photonics and Instrumentation, Centre for Integrated Optoelectronics, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
Qiongchan Shao
State Key Laboratory of Extreme Photonics and Instrumentation, Centre for Integrated Optoelectronics, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
Mingyu Li
School of Opto-Electronic Engineering, Changchun University of Science and Technology, Changchun 130022, China
Xiao Ma
School of Information and Electronic Engineering, Zhejiang University of Science and Technology, Hangzhou 310023, China
Jian-Jun He
State Key Laboratory of Extreme Photonics and Instrumentation, Centre for Integrated Optoelectronics, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China
The high-order microring filter has been proposed for a larger free spectral range (FSR) compared with the single microring filter; therefore, it has great potential to be used in wavelength division multiplexing (WDM) systems. In this article, we have designed and fabricated a second-order microring filter made up of two rings connected in series with two Ti thermal heaters deposited above them. The large FSR of 56.8 nm is obtained by decreasing the difference of the radii between the two series rings, achieving similar FSRs to that of higher-order filters but with a simpler and more compact design. The average electrical tuning efficiencies of the two heaters are 0.186 nm/mW and 0.207 nm/mW, and the center wavelength of the filter can be tuned over the entire FSR with an applied electrical power of less than 40 mW.
