Next Article in Journal
Employing Shadows for Multi-Person Tracking Based on a Single RGB-D Camera
Previous Article in Journal
On Field Infrared Thermography Sensing for PV System Efficiency Assessment: Results and Comparison with Electrical Models
Open AccessArticle

Tandem Mach Zehnder Directional Coupler Design and Simulation on Silicon Platform for Optical Coherence Tomography Applications

1
Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan
2
Graduate Institute of Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 11031, Taiwan
*
Authors to whom correspondence should be addressed.
Sensors 2020, 20(4), 1054; https://doi.org/10.3390/s20041054
Received: 20 December 2019 / Revised: 12 February 2020 / Accepted: 13 February 2020 / Published: 15 February 2020
(This article belongs to the Section Optical Sensors)
We design and compare the splitting ratio wavelength flatness of directional coupler (DC), Mach-Zehnder directional coupler (MZDC), and tandem MZDC. All coupler responses are analyzed, and tandem MZDC performance is the best in the wavelength insensitivity compared with the other two. An MZDC with any coupling ratio could be utilized to match the maximum flatness in a 40-nm wavelength range. To extend a broad flatness range, the tandem MZDC is proposed and still follows the Mach Zehnder structure taking two MZDCs as couplers connected through a decoupled region. Unlike DC, MZDC with the flat wavelength response has a non-linear output phase. Hence, using two wavelength-insensitive MZDCs as the coupling function in a tandem MZDC could demonstrate a more extensive decoupled phase term to maximize the flat wavelength response. The tandem MZDC theoretically demonstrates the splitting ratio with 100-nm flatness in the wavelength range from 1250 nm to 1350 nm. Finally, a point spread function through the tandem MZDC shows a 24-dB signal-to-noise ratio improvement in optical coherence tomography applications. View Full-Text
Keywords: Mach-Zehnder; directional coupler; optical coherence tomography Mach-Zehnder; directional coupler; optical coherence tomography
Show Figures

Figure 1

MDPI and ACS Style

Lu, Y.-T.; Widhianto, B.Y.B.; Hsu, S.-H.; Chang, C.-C. Tandem Mach Zehnder Directional Coupler Design and Simulation on Silicon Platform for Optical Coherence Tomography Applications. Sensors 2020, 20, 1054.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop