TY - JOUR
T1 - Asymmetric, non-uniform 3-dB directional coupler with 300-nm bandwidth and a small footprint
AU - Nikbakht, Hamed
AU - Khoshmehr, Mohammad Talebi
AU - van Someren, Bob
AU - Teichrib, Dieter
AU - Hammer, Manfred
AU - Förstner, Jens
AU - Akca, B. Imran
N1 - Publisher Copyright:
© 2023 Optica Publishing Group.
PY - 2023/1/15
Y1 - 2023/1/15
N2 - Here we demonstrate a new, to the best of our knowledge, type of 3-dB coupler that has an ultra-broadband operational range from 1300 to 1600nm with low fabrication sensitivity. The overall device size is 800 μm including in/out S-bend waveguides. The coupler is an asymmetric non-uniform directional coupler that consists of two tapered waveguides. One of the coupler arms is shifted by 100 μm in the propagation direction, which results in a more wavelength-insensitive 3-dB response compared to a standard (not shifted) coupler. Moreover, compared to a long adiabatic coupler, we achieved a similar wavelength response at a 16-times-smaller device length. The couplers were fabricated using the silicon nitride platform of Lionix International.We also experimentally demonstrated an optical switch that is made by using two of these couplers in a Mach-Zehnder interferometer configuration. According to experimental results, this optical switch exhibits -10 dB of extinction ratio over the 1500-1600nm wavelength range. Our results indicate that this new type of coupler holds great promise for various applications, including optical imaging, telecommunications, and reconfigurable photonic processors where compact, fabrication-tolerant, and wavelength-insensitive couplers are essential.
AB - Here we demonstrate a new, to the best of our knowledge, type of 3-dB coupler that has an ultra-broadband operational range from 1300 to 1600nm with low fabrication sensitivity. The overall device size is 800 μm including in/out S-bend waveguides. The coupler is an asymmetric non-uniform directional coupler that consists of two tapered waveguides. One of the coupler arms is shifted by 100 μm in the propagation direction, which results in a more wavelength-insensitive 3-dB response compared to a standard (not shifted) coupler. Moreover, compared to a long adiabatic coupler, we achieved a similar wavelength response at a 16-times-smaller device length. The couplers were fabricated using the silicon nitride platform of Lionix International.We also experimentally demonstrated an optical switch that is made by using two of these couplers in a Mach-Zehnder interferometer configuration. According to experimental results, this optical switch exhibits -10 dB of extinction ratio over the 1500-1600nm wavelength range. Our results indicate that this new type of coupler holds great promise for various applications, including optical imaging, telecommunications, and reconfigurable photonic processors where compact, fabrication-tolerant, and wavelength-insensitive couplers are essential.
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U2 - 10.1364/OL.476537
DO - 10.1364/OL.476537
M3 - Article
C2 - 36638419
AN - SCOPUS:85146364223
SN - 0146-9592
VL - 48
SP - 207
EP - 210
JO - Optics Letters
JF - Optics Letters
IS - 2
ER -